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Alex Protsenko
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id,displayName,message,tags,description,helpLink,target.type,target.platform,target.engineEdition,target.version,level
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AutoCreateStats,Auto-Create Statistics should be on,Turn Auto-Create Statistics option on to improve query performance.,"['DefaultRuleset', 'Performance', 'Statistics', 'QueryOptimizer']","The Query Optimizer determines whether an index is useful for a specific query by evaluating the stored statistics. If the statistics become out of date and significant changes have occurred against the underlying data, this can result in less than optimal query performance. In most cases, it's best to let SQL Server maintain the statistics. If you turn 'Auto Create Stats' and 'Auto Update Stats' off, then it is up to you to keep the statistics up-to-date somehow. Failure to do so will lead to poor query performance. Most applications should have these options ON.
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AutoCreateStats,Auto-Create Statistics should be on,Turn Auto-Create Statistics option on to improve query performance.,"['DefaultRuleset', 'Performance', 'Statistics', 'QueryOptimizer']","The Query Optimizer determines whether an index is useful for a specific query by evaluating the stored statistics. If the statistics become out of date and significant changes have occurred against the underlying data, this can result in less than optimal query performance. In most cases, it's best to let SQL Server maintain the statistics. If you turn 'Auto Create Stats' and 'Auto Update Stats' off, then it is up to you to keep the statistics up-to-date somehow. Failure to do so will lead to poor query performance. Most applications should have these options ON.
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When the Auto Create statistics setting is ON, the Query Optimizer creates statistics on one or more columns of a table or an indexed view, as necessary, to improve query plans and query performance.",https://docs.microsoft.com/sql/relational-databases/statistics/statistics#CreateStatistics,Database,/^(Windows|Linux)$/,"OnPremises, ManagedInstance",,Warning
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AutoUpdateStats,Auto-Update Statistics should be on,Turn Auto-Update Statistics option on to improve query performance.,"['DefaultRuleset', 'Performance', 'Statistics', 'QueryOptimizer']","The Query Optimizer determines whether an index is useful for a specific query by evaluating the stored statistics. If the statistics become out of date and significant changes have occurred against the underlying data, this can result in less than optimal query performance. In most cases, it's best to let SQL Server maintain the statistics. If you turn 'Auto Create Stats' and 'Auto Update Stats' off, then it is up to you to keep the statistics up-to-date somehow. Failure to do so will lead to poor query performance. Most applications should have these options ON.
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AutoUpdateStats,Auto-Update Statistics should be on,Turn Auto-Update Statistics option on to improve query performance.,"['DefaultRuleset', 'Performance', 'Statistics', 'QueryOptimizer']","The Query Optimizer determines whether an index is useful for a specific query by evaluating the stored statistics. If the statistics become out of date and significant changes have occurred against the underlying data, this can result in less than optimal query performance. In most cases, it's best to let SQL Server maintain the statistics. If you turn 'Auto Create Stats' and 'Auto Update Stats' off, then it is up to you to keep the statistics up-to-date somehow. Failure to do so will lead to poor query performance. Most applications should have these options ON.
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When the Auto Update Statistics setting is ON, the Query Optimizer updates statistics when they are used by a query and when they might be out-of-date. Statistics become out-of-date after insert, update, delete, or merge operations change the data distribution in the table or indexed view. The Query Optimizer determines when statistics might be out-of-date by counting the number of data modifications since the last statistics update and comparing the number of modifications to a threshold. The threshold is based on the number of rows in the table or indexed view. The Query Optimizer checks for out-of-date statistics before compiling a query and before executing a cached query plan. Before compiling a query, the Query Optimizer uses the columns, tables, and indexed views in the query predicate to determine which statistics might be out-of-date. Before executing a cached query plan, the Database Engine verifies that the query plan references up-to-date statistics. The AUTO_UPDATE_STATISTICS option applies to statistics created for indexes, single-columns in query predicates, and statistics that are created by using the CREATE STATISTICS statement. This option also applies to filtered statistics.",https://docs.microsoft.com/sql/relational-databases/statistics/statistics#UpdateStatistics,Database,/^(Windows|Linux)$/,"OnPremises, ManagedInstance",,Warning
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QueryStoreOn,Query Store should be active,Make sure Query Store actual operation mode is 'Read Write' to keep your performance analysis accurate,"['DefaultRuleset', 'Performance', 'QueryStore', 'Statistics']","The Query Store feature provides you with insight on query plan choice and performance. It simplifies performance troubleshooting by helping you quickly find performance differences caused by query plan changes. Query Store automatically captures a history of queries, plans, and runtime statistics, and retains these for your review. It separates data by time windows so you can see database usage patterns and understand when query plan changes happened on the server. While Query Store collects queries, execution plans and statistics, its size in the database grows until this limit is reached. When that happens, Query Store automatically changes the operation mode to read-only and stops collecting new data, which means that your performance analysis is no longer accurate.",https://docs.microsoft.com/sql/relational-databases/performance/monitoring-performance-by-using-the-query-store,Database,/^(Windows|Linux)$/,"OnPremises, ManagedInstance","[13.0,)",Warning
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TF174,TF 174 increases the plan cache bucket count,Consider enabling trace flag 174 to increase the plan cache bucket count.,"['DefaultRuleset', 'TraceFlag', 'Memory', 'Performance']","Trace Flag 174 increases the SQL Server plan cache bucket count from 40,009 to 160,001 on 64-bit systems.
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When the SQL Server plan cache reaches its entry limit, plans that have low cost must be evicted in order to insert new plans. This can cause severe contention on the SOS_CACHESTORE spinlock and a high CPU usage occurs in SQL Server.
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TF174,TF 174 increases the plan cache bucket count,Consider enabling trace flag 174 to increase the plan cache bucket count.,"['DefaultRuleset', 'TraceFlag', 'Memory', 'Performance']","Trace Flag 174 increases the SQL Server plan cache bucket count from 40,009 to 160,001 on 64-bit systems.
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When the SQL Server plan cache reaches its entry limit, plans that have low cost must be evicted in order to insert new plans. This can cause severe contention on the SOS_CACHESTORE spinlock and a high CPU usage occurs in SQL Server.
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On 64-bit systems, the number of buckets for the SQL Server plan cache is 40,009. Therefore, the maximum number of entries that can fit inside the SQL Server plan cache is 160,036. Enabling trace flag 174 on high performance systems increases the size of the cache and can avoid SOS_CACHESTORE spinlock contention.",https://docs.microsoft.com/sql/t-sql/database-console-commands/dbcc-traceon-trace-flags-transact-sql,Server,/^(Windows|Linux)$/,OnPremises,"['[11.0.3368,12.0)', '[12.0.2480,13.0)', '[13.0,)']",Information
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TF634,TF 634 disables background columnstore compression,Trace Flag 634 disables the background columnstore compression task. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'Memory', 'Performance', 'ColumnStore']","Trace Flag 634 disables the background columnstore compression task.
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SQL Server periodically runs the Tuple Mover background task that compresses columnstore index rowgroups with uncompressed data, one such rowgroup at a time.
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Columnstore compression improves query performance but also consumes system resources.
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TF634,TF 634 disables background columnstore compression,Trace Flag 634 disables the background columnstore compression task. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'Memory', 'Performance', 'ColumnStore']","Trace Flag 634 disables the background columnstore compression task.
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SQL Server periodically runs the Tuple Mover background task that compresses columnstore index rowgroups with uncompressed data, one such rowgroup at a time.
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Columnstore compression improves query performance but also consumes system resources.
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You can control the timing of columnstore compression manually, by disabling the background compression task with trace flag 634, and then explicitly invoking ALTER INDEX...REORGANIZE or ALTER INDEX...REBUILD at the time of your choice.",https://docs.microsoft.com/sql/t-sql/database-console-commands/dbcc-traceon-trace-flags-transact-sql,Server,/^(Windows|Linux)$/,OnPremises,,Information
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TF652,TF 652 disables page pre-fetching scans,Trace Flag 652 disables Page Pre-fetching Scans. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'Performance', 'Memory', 'Pages']","Trace Flag 652 disables page pre-fetching for scans.
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The read-ahead process reads the full extent of a referenced database page into the buffer pool, before those contiguous database pages are consumed by scans.
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TF652,TF 652 disables page pre-fetching scans,Trace Flag 652 disables Page Pre-fetching Scans. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'Performance', 'Memory', 'Pages']","Trace Flag 652 disables page pre-fetching for scans.
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The read-ahead process reads the full extent of a referenced database page into the buffer pool, before those contiguous database pages are consumed by scans.
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Enabling the trace flag can lead to performance issues on queries that leverage pre-fetching.",http://support.microsoft.com/kb/920093,Server,Windows,OnPremises,,Information
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TF661,TF 661 disables Ghost Cleanup Task,Trace flag 661 disables the background ghost cleanup task. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'Performance']","Trace Flag 661 disables the ghost record removal process. A ghost record is the result of a delete operation.
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When you delete a record, the deleted record is kept as a ghost record. Later, the deleted record is purged by the ghost record removal process. When you disable this process, the deleted record is not purged.
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Therefore, the space that the deleted record consumes is not freed. This behavior affects space consumption and the performance of scan operations.
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TF661,TF 661 disables Ghost Cleanup Task,Trace flag 661 disables the background ghost cleanup task. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'Performance']","Trace Flag 661 disables the ghost record removal process. A ghost record is the result of a delete operation.
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When you delete a record, the deleted record is kept as a ghost record. Later, the deleted record is purged by the ghost record removal process. When you disable this process, the deleted record is not purged.
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Therefore, the space that the deleted record consumes is not freed. This behavior affects space consumption and the performance of scan operations.
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If you turn off this trace Flag, the ghost record removal process works correctly.",https://support.microsoft.com/help/920093,Server,Windows,OnPremises,,Information
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TF834,TF 834 enables large-page allocations,Enable trace flag 834 to use large-page allocations to improve analytical and data warehousing workloads.,"['DefaultRuleset', 'TraceFlag', 'Performance', 'Memory', 'ColumnStore']","Trace Flag 834 causes the server to use large-page memory (LPM) model for the buffer pool allocations. Consider enabling TF 834 if you have a server that has a lot of memory, particularly for an analytical or data warehousing workload. Trace flag 834 is NOT recommended on SQL Server instances that use columnstore indexes.",https://support.microsoft.com/help/4465518,Server,/^(Windows|Linux)$/,OnPremises,,Information
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TF845,TF 845 is not needed in SQL Server 2012 and higher versions,Disable trace flag 845 in SQL Server 2012 and higher versions.,"['DefaultRuleset', 'TraceFlag', 'Memory', 'Performance']","Trace Flag 845 supports locking pages in memory in SQL Server Standard edition, which is needed together with trace flag 834 to use the large-page memory (LPM) model for the buffer pool allocations.
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Consider enabling TF 834 if you have a server that has a lot of memory, particularly for an analytical or data warehousing workload.
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TF845,TF 845 is not needed in SQL Server 2012 and higher versions,Disable trace flag 845 in SQL Server 2012 and higher versions.,"['DefaultRuleset', 'TraceFlag', 'Memory', 'Performance']","Trace Flag 845 supports locking pages in memory in SQL Server Standard edition, which is needed together with trace flag 834 to use the large-page memory (LPM) model for the buffer pool allocations.
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Consider enabling TF 834 if you have a server that has a lot of memory, particularly for an analytical or data warehousing workload.
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Starting with SQL Server 2012 this behavior is enabled by default for Standard edition, and trace flag 845 must not be used.",https://docs.microsoft.com/sql/t-sql/database-console-commands/dbcc-traceon-trace-flags-transact-sql,Server,Windows,OnPremises,"[11.0,)",Warning
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TF902,TF 902: Database Upgrade Bypass should be disabled,Disable trace flag 902 which bypasses database upgrade.,"['DefaultRuleset', 'TraceFlag', 'UpdateIssues']","Trace Flag 902 bypasses execution of database upgrade script when installing a Cumulative Update or Service Pack.
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This trace flag is not supported to run it continuously in a production environment.
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TF902,TF 902: Database Upgrade Bypass should be disabled,Disable trace flag 902 which bypasses database upgrade.,"['DefaultRuleset', 'TraceFlag', 'UpdateIssues']","Trace Flag 902 bypasses execution of database upgrade script when installing a Cumulative Update or Service Pack.
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This trace flag is not supported to run it continuously in a production environment.
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If you encounter an error during script upgrade mode, it is recommended to contact Microsoft SQL Customer Service and Support (CSS) for further guidance.",https://support.microsoft.com/help/2163980,Server,Windows,OnPremises,,Warning
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TF1117,TF 1117 Enables Filegroup-level Autogrow,Consider enabling trace flag 1117 to enable filegroup autogrow.,"['DefaultRuleset', 'TraceFlag', 'DBFileConfiguration', 'Performance']","Trace Flag 1117 initiates the growth of every file in the filegroup, when a file in the filegroup meets the autogrow threshold, and together with trace flag 1118, can help reduce allocation contention in the SQL Server TempDB database.
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TF1117,TF 1117 Enables Filegroup-level Autogrow,Consider enabling trace flag 1117 to enable filegroup autogrow.,"['DefaultRuleset', 'TraceFlag', 'DBFileConfiguration', 'Performance']","Trace Flag 1117 initiates the growth of every file in the filegroup, when a file in the filegroup meets the autogrow threshold, and together with trace flag 1118, can help reduce allocation contention in the SQL Server TempDB database.
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This trace flag affects all databases and is recommended only if every database is safe to be grow all files in a filegroup by the same amount.",https://support.microsoft.com/help/2154845,Server,Windows,OnPremises,,Information
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TF1118,TF 1118 Disables Single Page Allocations,Consider enabling trace flag 1118 to force page allocations on uniform extents.,"['DefaultRuleset', 'TraceFlag', 'Memory', 'Performance', 'Pages']","Trace Flag 1118 forces page allocations on uniform extents instead of mixed extents, and together with trace flag 1117, can help reduce allocation contention in the SQL Server TempDB database.
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When a new object is created, by default, the first eight pages are allocated from different extents (mixed extents).
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Afterwards, when more pages are needed, those are allocated from that same extent (uniform extent).
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The SGAM page is used to track these mixed extents, so can quickly become a bottleneck when numerous mixed page allocations are occurring.
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TF1118,TF 1118 Disables Single Page Allocations,Consider enabling trace flag 1118 to force page allocations on uniform extents.,"['DefaultRuleset', 'TraceFlag', 'Memory', 'Performance', 'Pages']","Trace Flag 1118 forces page allocations on uniform extents instead of mixed extents, and together with trace flag 1117, can help reduce allocation contention in the SQL Server TempDB database.
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When a new object is created, by default, the first eight pages are allocated from different extents (mixed extents).
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Afterwards, when more pages are needed, those are allocated from that same extent (uniform extent).
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The SGAM page is used to track these mixed extents, so can quickly become a bottleneck when numerous mixed page allocations are occurring.
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This trace flag allocates all eight pages from the same extent when creating new objects, minimizing the need to scan the SGAM page and forces uniform extent allocations instead of mixed page allocations.",https://support.microsoft.com/help/328551,Server,Windows,OnPremises,,Information
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TF1204,TF 1204 returns deadlock information,Trace Flag 1204 returns deadlock information.,"['DefaultRuleset', 'TraceFlag', 'Locks', 'Performance']","Trace Flag 1204 returns the resources and types of locks that are participating in a deadlock, including the affected command.
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TF1204,TF 1204 returns deadlock information,Trace Flag 1204 returns deadlock information.,"['DefaultRuleset', 'TraceFlag', 'Locks', 'Performance']","Trace Flag 1204 returns the resources and types of locks that are participating in a deadlock, including the affected command.
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The resulting information is recorded in the SQL Server Errorlog.",https://support.microsoft.com/help/832524,Server,/^(Windows|Linux)$/,OnPremises,,Information
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TF1211,TF 1211: Lock Escalation should be enabled,Disable trace flag 1211 to allow lock escalation.,"['DefaultRuleset', 'TraceFlag', 'Locks', 'Performance']","Trace Flag 1211 disables lock escalation based on memory pressure, or based on number of locks. Because SQL Server will not escalate row or page locks to table locks, this can generate an excessive number of locks. If the lock memory grows large enough, attempts to allocate additional locks for any query may fail and cause performance issues.
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TF1211,TF 1211: Lock Escalation should be enabled,Disable trace flag 1211 to allow lock escalation.,"['DefaultRuleset', 'TraceFlag', 'Locks', 'Performance']","Trace Flag 1211 disables lock escalation based on memory pressure, or based on number of locks. Because SQL Server will not escalate row or page locks to table locks, this can generate an excessive number of locks. If the lock memory grows large enough, attempts to allocate additional locks for any query may fail and cause performance issues.
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This trace flag should not be used in order to avoid inability to allocate lock resources because of insufficient memory. If lock escalation needs to be disabled, use trace flag 1224 instead.",https://docs.microsoft.com/sql/t-sql/database-console-commands/dbcc-traceon-trace-flags-transact-sql,Server,/^(Windows|Linux)$/,OnPremises,,Warning
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TF1222,TF 1222 returns deadlock information,Trace Flag 1222 returns deadlock information.,"['DefaultRuleset', 'TraceFlag', 'Locks', 'Performance']","Trace Flag 1222 returns the resources and types of locks that are participating in a deadlock, including the affected command.
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TF1222,TF 1222 returns deadlock information,Trace Flag 1222 returns deadlock information.,"['DefaultRuleset', 'TraceFlag', 'Locks', 'Performance']","Trace Flag 1222 returns the resources and types of locks that are participating in a deadlock, including the affected command.
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The resulting information is recorded in the SQL Server Errorlog, in XML format that does not comply with any XSD schema.",https://docs.microsoft.com/sql/t-sql/database-console-commands/dbcc-traceon-trace-flags-transact-sql,Server,/^(Windows|Linux)$/,OnPremises,,Information
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TF1224,TF 1224 should be disabled,Disable trace flag 1224 to allow lock escalation.,"['DefaultRuleset', 'TraceFlag', 'Locks', 'Performance']","Trace Flag 1224 disables lock escalation based on the number of locks, unless SQL Server is under memory pressure. Because SQL Server will not escalate row or page locks to table locks, this can generate an excessive number of locks.",https://docs.microsoft.com/sql/t-sql/database-console-commands/dbcc-traceon-trace-flags-transact-sql,Server,/^(Windows|Linux)$/,OnPremises,,Warning
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TF1229,TF 1229: Lock Partitioning should be enabled,Disable trace flag 1229 to allow lock partitioning.,"['DefaultRuleset', 'TraceFlag', 'Locks', 'Performance', 'CPU']","Trace Flag 1229 disables lock partitioning regardless of the number of CPUs. By default, SQL Server enables lock partitioning when a server has 16 or more CPUs, to improve the scalability characteristics of larger systems.
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TF1229,TF 1229: Lock Partitioning should be enabled,Disable trace flag 1229 to allow lock partitioning.,"['DefaultRuleset', 'TraceFlag', 'Locks', 'Performance', 'CPU']","Trace Flag 1229 disables lock partitioning regardless of the number of CPUs. By default, SQL Server enables lock partitioning when a server has 16 or more CPUs, to improve the scalability characteristics of larger systems.
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Disabling lock partitioning may cause can cause spinlock contention and poor performance, or unexpected behaviors when switching partitions.",https://docs.microsoft.com/sql/t-sql/database-console-commands/dbcc-traceon-trace-flags-transact-sql,Server,/^(Windows|Linux)$/,OnPremises,,Warning
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TF1236,TF 1236: Database Lock Partitioning should be enabled,Enable trace Flag 1236 to allow database lock partitioning.,"['DefaultRuleset', 'TraceFlag', 'Locks', 'Performance']","Trace Flag 1236 enables database-level lock partitioning.
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TF1236,TF 1236: Database Lock Partitioning should be enabled,Enable trace Flag 1236 to allow database lock partitioning.,"['DefaultRuleset', 'TraceFlag', 'Locks', 'Performance']","Trace Flag 1236 enables database-level lock partitioning.
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Lock Partitioning is utilized to improve the scalability characteristics on larger systems.",https://support.microsoft.com/help/2926217,Server,Windows,OnPremises,"[9.0,)",Warning
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TF1462,TF 1462 should be disabled to allow Log Stream Compression,Disable trace flag 1462 to allow log stream compression.,"['DefaultRuleset', 'TraceFlag', 'Performance', 'AvailabilityGroups']","Trace Flag 1462 disables log stream compression for asynchronous availability groups.
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TF1462,TF 1462 should be disabled to allow Log Stream Compression,Disable trace flag 1462 to allow log stream compression.,"['DefaultRuleset', 'TraceFlag', 'Performance', 'AvailabilityGroups']","Trace Flag 1462 disables log stream compression for asynchronous availability groups.
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This feature is enabled by default on asynchronous replicas to optimize network bandwidth.",https://docs.microsoft.com/sql/database-engine/availability-groups/windows/tune-compression-for-availability-group,Server,/^(Windows|Linux)$/,OnPremises,,Warning
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TF2312,TF 2312 sets the default Cardinality Estimation model,Trace Flag 2312 does not apply to this SQL Server version. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'QueryOptimizer', 'Performance']","Trace Flag 2312 sets the Query Optimizer cardinality estimation model to the default version of the database compability level of SQL Server 2014 and higher versions. If the database compatibility level is lower than 120, enabling trace flag 2312 uses the cardinality estimation model of SQL Server 2014 (120).",https://support.microsoft.com/help/2801413,Server,Windows,OnPremises,,Warning
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TF2330,TF 2330 disables recording of index usage stats,Trace Flag 2330 does not apply to this SQL Server version. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'Performance', 'Indexes']","Trace Flag 2330 disables recording of index usage stats, which could lead to a non-yielding condition in SQL 2005.",,Server,/^(Windows|Linux)$/,OnPremises,"[10.0,)",Warning
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TF2340,TF 2340 disables Batch Sorts for optimized nested loops joins,Trace Flag 2340 disables Batch Sorts for optimized nested loops joins.,"['DefaultRuleset', 'TraceFlag', 'QueryOptimizer', 'Performance']","Trace Flag 2340 causes SQL Server not to use a sort operation (batch sort) for optimized nested loops joins when generating a plan.
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TF2340,TF 2340 disables Batch Sorts for optimized nested loops joins,Trace Flag 2340 disables Batch Sorts for optimized nested loops joins.,"['DefaultRuleset', 'TraceFlag', 'QueryOptimizer', 'Performance']","Trace Flag 2340 causes SQL Server not to use a sort operation (batch sort) for optimized nested loops joins when generating a plan.
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Verify need to set a non-default trace flag with the current system build and configuration.",https://docs.microsoft.com/sql/t-sql/database-console-commands/dbcc-traceon-trace-flags-transact-sql,Server,/^(Windows|Linux)$/,OnPremises,,Information
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TF2371,TF 2371 enables a linear recompilation threshold for statistics,Enable trace Flag 2371 to allow a linear recompilation threshold for statistics.,"['DefaultRuleset', 'TraceFlag', 'Performance', 'Statistics']","Trace Flag 2371 causes SQL Server to change the fixed update statistics threshold to a linear update statistics threshold.
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TF2371,TF 2371 enables a linear recompilation threshold for statistics,Enable trace Flag 2371 to allow a linear recompilation threshold for statistics.,"['DefaultRuleset', 'TraceFlag', 'Performance', 'Statistics']","Trace Flag 2371 causes SQL Server to change the fixed update statistics threshold to a linear update statistics threshold.
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This is especially useful to keep statistics updated on large tables.",https://docs.microsoft.com/sql/t-sql/database-console-commands/dbcc-traceon-trace-flags-transact-sql,Server,Windows,OnPremises,"[10.5.2500,)",Information
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TF2389,TF 2389 enables automatic statistics for Ascending Keys,Trace Flag 2389 enables automatic statistics for ascending keys. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'Statistics', 'Performance']","Trace Flag 2389 enables automatically generated quick statistics for ascending keys (histogram amendment).
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This trace flag is recommended to be set in cases where queries access newly inserted ascending key values (such as an IDENTITY column), but the new values are not yet updated in the statistics histogram for the affected columns. In this case the histogram used to estimate cardinality will be adjusted at query compile time.
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TF2389,TF 2389 enables automatic statistics for Ascending Keys,Trace Flag 2389 enables automatic statistics for ascending keys. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'Statistics', 'Performance']","Trace Flag 2389 enables automatically generated quick statistics for ascending keys (histogram amendment).
|
||||
This trace flag is recommended to be set in cases where queries access newly inserted ascending key values (such as an IDENTITY column), but the new values are not yet updated in the statistics histogram for the affected columns. In this case the histogram used to estimate cardinality will be adjusted at query compile time.
|
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Verify need to set a non-default trace flag with the current system build and configuration.",https://support.microsoft.com/help/2801413,Server,/^(Windows|Linux)$/,"OnPremises, ManagedInstance",,Information
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TF2390,TF 2390 enables automatic statistics for Ascending or Unknown Keys,Trace Flag 2390 enables automatic statistics for ascending or unknown keys. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'Statistics', 'Performance', 'Indexes']","Trace Flag 2390 enables automatically generated quick statistics for ascending or unknown keys (histogram amendment).
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This trace flag is recommended to be set in cases where queries access newly inserted ascending key values (such as an IDENTITY column), but the new values are not yet updated in the statistics histogram for the affected columns. In this case the histogram used to estimate cardinality will be adjusted at query compile time.
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TF2390,TF 2390 enables automatic statistics for Ascending or Unknown Keys,Trace Flag 2390 enables automatic statistics for ascending or unknown keys. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'Statistics', 'Performance', 'Indexes']","Trace Flag 2390 enables automatically generated quick statistics for ascending or unknown keys (histogram amendment).
|
||||
This trace flag is recommended to be set in cases where queries access newly inserted ascending key values (such as an IDENTITY column), but the new values are not yet updated in the statistics histogram for the affected columns. In this case the histogram used to estimate cardinality will be adjusted at query compile time.
|
||||
Verify need to set a non-default trace flag with the current system build and configuration.",https://support.microsoft.com/help/2801413,Server,/^(Windows|Linux)$/,"OnPremises, ManagedInstance",,Information
|
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TF2528,TF 2528 disables parallel operations for integrity checking,Trace Flag 2528 disables parallel operations for integrity checking.,"['DefaultRuleset', 'TraceFlag', 'DataIntegrity', 'DBCC']","Trace Flag 2528 disables parallel checking of objects by DBCC CHECKDB, DBCC CHECKFILEGROUP, and DBCC CHECKTABLE.
|
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By default, the degree of parallelism is automatically determined by the query processor. The maximum degree of parallelism is configured just like that of parallel queries.
|
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When parallel checks are disabled, the DBCC commands will take longer to complete.
|
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TF2528,TF 2528 disables parallel operations for integrity checking,Trace Flag 2528 disables parallel operations for integrity checking.,"['DefaultRuleset', 'TraceFlag', 'DataIntegrity', 'DBCC']","Trace Flag 2528 disables parallel checking of objects by DBCC CHECKDB, DBCC CHECKFILEGROUP, and DBCC CHECKTABLE.
|
||||
By default, the degree of parallelism is automatically determined by the query processor. The maximum degree of parallelism is configured just like that of parallel queries.
|
||||
When parallel checks are disabled, the DBCC commands will take longer to complete.
|
||||
Starting with SQL Server 2014 SP2, a MAXDOP option is available to override the max degree of parallelism configuration option of sp_configure for the DBCC statements.",https://docs.microsoft.com/sql/t-sql/database-console-commands/dbcc-traceon-trace-flags-transact-sql,Server,/^(Windows|Linux)$/,OnPremises,,Warning
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TF2549,TF 2549 optimizes PHYSICAL_ONLY option of DBCC CHECKDB,Trace Flag 2549 forces DBCC CHECKDB to treat different physical files as one logical file.,"['DefaultRuleset', 'TraceFlag', 'DBCC']","Trace Flag 2549 forces the DBCC CHECKDB command to assume each database file is on a unique disk drive but treating different physical files as one logical file.
|
||||
TF2549,TF 2549 optimizes PHYSICAL_ONLY option of DBCC CHECKDB,Trace Flag 2549 forces DBCC CHECKDB to treat different physical files as one logical file.,"['DefaultRuleset', 'TraceFlag', 'DBCC']","Trace Flag 2549 forces the DBCC CHECKDB command to assume each database file is on a unique disk drive but treating different physical files as one logical file.
|
||||
This trace flag can improve the performance when using the PHYSICAL_ONLY option, but it's not recommended unless it is known that each file is based on a unique physical disk.",https://support.microsoft.com/help/2634571,Server,/^(Windows|Linux)$/,OnPremises,,Warning
|
||||
TF2562,TF 2562 forces the DBCC CHECKDB command to execute in a single batch,Trace Flag 2562 forces the DBCC CHECKDB command to execute in a single batch.,"['DefaultRuleset', 'TraceFlag', 'DBCC', 'TempDB']","Trace Flag 2562 forces the DBCC CHECKDB command to execute in a single batch regardless of the number of indexes in the database.
|
||||
TF2562,TF 2562 forces the DBCC CHECKDB command to execute in a single batch,Trace Flag 2562 forces the DBCC CHECKDB command to execute in a single batch.,"['DefaultRuleset', 'TraceFlag', 'DBCC', 'TempDB']","Trace Flag 2562 forces the DBCC CHECKDB command to execute in a single batch regardless of the number of indexes in the database.
|
||||
This trace flag can improve the performance when using the PHYSICAL_ONLY option, but space requirements for TempDB may increase.",https://support.microsoft.com/help/2634571,Server,/^(Windows|Linux)$/,OnPremises,,Warning
|
||||
TF2566,TF 2566 disables default data purity check,Trace Flag 2566 disables default data purity check.,"['DefaultRuleset', 'TraceFlag', 'DBCC', 'DataIntegrity']","Trace Flag 2566 forces the DBCC CHECKDB command to execute without data purity check unless the DATA_PURITY option is specified.
|
||||
TF2566,TF 2566 disables default data purity check,Trace Flag 2566 disables default data purity check.,"['DefaultRuleset', 'TraceFlag', 'DBCC', 'DataIntegrity']","Trace Flag 2566 forces the DBCC CHECKDB command to execute without data purity check unless the DATA_PURITY option is specified.
|
||||
For databases upgraded from earlier versions of SQL Server, it is recommended to run the DBCC CHECKDB WITH DATA_PURITY command at least once, to enable column-value integrity checks to happen by default.",https://support.microsoft.com/help/945770,Server,/^(Windows|Linux)$/,OnPremises,,Warning
|
||||
TF3023,TF 3023 enables Backup Checksum option by default,Trace Flag 3023 enables CHECKSUM option as default for BACKUP command.,"['DefaultRuleset', 'TraceFlag', 'Backup']","Trace Flag 3023 enables the CHECKSUM option of the BACKUP command by default.
|
||||
This trace flag forces the CHECKSUM option for BACKUP command even when not explicitely set.
|
||||
TF3023,TF 3023 enables Backup Checksum option by default,Trace Flag 3023 enables CHECKSUM option as default for BACKUP command.,"['DefaultRuleset', 'TraceFlag', 'Backup']","Trace Flag 3023 enables the CHECKSUM option of the BACKUP command by default.
|
||||
This trace flag forces the CHECKSUM option for BACKUP command even when not explicitely set.
|
||||
Starting with SQL Server 2014, this behavior is controlled by setting the Backup Checksum Default configuration option.",https://support.microsoft.com/help/2656988,Server,Windows,OnPremises,,Information
|
||||
TF3042,TF 3042 bypasses the default backup compression pre-allocation algorithm,Trace Flag 3042 enables the bypass of the default backup compression.,"['DefaultRuleset', 'TraceFlag', 'Backup']","Trace Flag 3042 bypasses the default backup compression pre-allocation algorithm to allow the backup file to grow only as needed to reach its final size.
|
||||
TF3042,TF 3042 bypasses the default backup compression pre-allocation algorithm,Trace Flag 3042 enables the bypass of the default backup compression.,"['DefaultRuleset', 'TraceFlag', 'Backup']","Trace Flag 3042 bypasses the default backup compression pre-allocation algorithm to allow the backup file to grow only as needed to reach its final size.
|
||||
This trace flag can achieve space savings by allocating only the actual size required for the compressed backup, but might increase the overall backup operation time.",https://docs.microsoft.com/sql/relational-databases/backup-restore/backup-compression-sql-server,Server,/^(Windows|Linux)$/,OnPremises,,Information
|
||||
TF3226,TF 3226 disables ErrorLog entries for every successful backup operation,Trace Flag 3226 disables ErrorLog entries for every successful backup operation.,"['DefaultRuleset', 'TraceFlag', 'Backup']","Trace Flag 3226 prevents SQL Server from recording an entry to the Errorlog on every successful backup operation.
|
||||
TF3226,TF 3226 disables ErrorLog entries for every successful backup operation,Trace Flag 3226 disables ErrorLog entries for every successful backup operation.,"['DefaultRuleset', 'TraceFlag', 'Backup']","Trace Flag 3226 prevents SQL Server from recording an entry to the Errorlog on every successful backup operation.
|
||||
Backup operations are registered in the Errorlog by default. Frequent backup operations can contribute to massive Errorlog files that become unwieldy.",https://docs.microsoft.com/sql/t-sql/database-console-commands/dbcc-traceon-trace-flags-transact-sql,Server,/^(Windows|Linux)$/,OnPremises,,Information
|
||||
TF4136,TF 4136 disables Parameter Sniffing,Trace Flag 4136 does not apply to this SQL Server version. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag']","Trace Flag 4136 disables parameter sniffing unless OPTION(RECOMPILE), WITH RECOMPILE or OPTIMIZE FOR value is used, but does not apply to this SQL Server version. Starting with SQL Server 2016, to accomplish this at the database level use the PARAMETER_SNIFFING option in ALTER DATABASE SCOPED CONFIGURATION. Verify need to set a non-default trace flag with the current system build and configuration.",https://support.microsoft.com/help/980653,Server,/^(Windows|Linux)$/,OnPremises,,Warning
|
||||
TF4137,TF 4137 causes plans to use partial correlation for filters,Trace flag 4137 does not apply to this SQL Server version. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'QueryOptimizer', 'Performance']","Trace Flag 4137 causes SQL Server to generate a plan using minimum selectivity when estimating AND predicates for filters to account for partial correlation instead of independence, under the query optimizer cardinality estimation model of SQL Server 2012 and earlier versions (CE 70). However it does not apply to this SQL Server version.
|
||||
Does not apply to CE version 120 or above. Use trace flag 9471 instead.
|
||||
Starting with SQL Server 2016 SP1, to accomplish this at the query level use the USE HINT 'ASSUME_MIN_SELECTIVITY_FOR_FILTER_ESTIMATES' query hint.
|
||||
TF4137,TF 4137 causes plans to use partial correlation for filters,Trace flag 4137 does not apply to this SQL Server version. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'QueryOptimizer', 'Performance']","Trace Flag 4137 causes SQL Server to generate a plan using minimum selectivity when estimating AND predicates for filters to account for partial correlation instead of independence, under the query optimizer cardinality estimation model of SQL Server 2012 and earlier versions (CE 70). However it does not apply to this SQL Server version.
|
||||
Does not apply to CE version 120 or above. Use trace flag 9471 instead.
|
||||
Starting with SQL Server 2016 SP1, to accomplish this at the query level use the USE HINT 'ASSUME_MIN_SELECTIVITY_FOR_FILTER_ESTIMATES' query hint.
|
||||
Verify need to set a non-default trace flag with the current system build and configuration.",https://support.microsoft.com/help/2658214,Server,/^(Windows|Linux)$/,OnPremises,,Warning
|
||||
TF4138,TF 4138 causes plans to not use Row Goal adjustments,Trace flag 4138 does not apply to this SQL Server version. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'QueryOptimizer', 'Performance']","Trace Flag 4138 causes SQL Server to generate a plan that does not use row goal adjustments with queries that contain TOP, OPTION (FAST N), IN, or EXISTS keywords.
|
||||
Starting with SQL Server 2016 SP1, to accomplish this at the query level use the USE HINT 'DISABLE_OPTIMIZER_ROWGOAL' query hint. However it does not apply to this SQL Server version.
|
||||
TF4138,TF 4138 causes plans to not use Row Goal adjustments,Trace flag 4138 does not apply to this SQL Server version. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'QueryOptimizer', 'Performance']","Trace Flag 4138 causes SQL Server to generate a plan that does not use row goal adjustments with queries that contain TOP, OPTION (FAST N), IN, or EXISTS keywords.
|
||||
Starting with SQL Server 2016 SP1, to accomplish this at the query level use the USE HINT 'DISABLE_OPTIMIZER_ROWGOAL' query hint. However it does not apply to this SQL Server version.
|
||||
Verify need to set a Non-default trace flag with current system build and configuration.",https://support.microsoft.com/help/2667211,Server,/^(Windows|Linux)$/,OnPremises,,Warning
|
||||
TF4139,TF 4139 enables automatic statistics for any key ordering,Trace flag 4139 does not apply to this SQL Server version. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'Statistics']","Trace Flag 4139 enables automatically generated quick statistics (histogram amendment) regardless of key column status.
|
||||
However, this trace flag does not apply to this SQL Server version.
|
||||
TF4139,TF 4139 enables automatic statistics for any key ordering,Trace flag 4139 does not apply to this SQL Server version. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'Statistics']","Trace Flag 4139 enables automatically generated quick statistics (histogram amendment) regardless of key column status.
|
||||
However, this trace flag does not apply to this SQL Server version.
|
||||
Verify need to set a non-default trace flag with the current system build and configuration.",https://support.microsoft.com/help/2952101,Server,/^(Windows|Linux)$/,OnPremises,,Warning
|
||||
TF4199,TF 4199 enables Query Optimizer fixes,Trace Flag 4199 enables Query Optimizer fixes. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'QueryOptimizer']",Trace Flag 4199 enables Query Optimizer fixes released in SQL Server Cumulative Updates and Service Packs.,http://support.microsoft.com/help/974006,Server,/^(Windows|Linux)$/,OnPremises,"[9.0.4035,)",Information
|
||||
TF6498,TF 6498 enables additional concurrent large queries,Trace Flag 6498 does not apply to this SQL Server version. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'Performance', 'Memory']","Trace Flag 6498 enables more than one large query compilation to gain access to the big gateway when there is sufficient memory available.
|
||||
However, this trace flag does not apply to this SQL Server version.
|
||||
This trace flag can be used to keep memory usage for the compilation of incoming queries under control, avoiding compilation waits for concurrent large queries.
|
||||
TF6498,TF 6498 enables additional concurrent large queries,Trace Flag 6498 does not apply to this SQL Server version. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'Performance', 'Memory']","Trace Flag 6498 enables more than one large query compilation to gain access to the big gateway when there is sufficient memory available.
|
||||
However, this trace flag does not apply to this SQL Server version.
|
||||
This trace flag can be used to keep memory usage for the compilation of incoming queries under control, avoiding compilation waits for concurrent large queries.
|
||||
Starting with SQL Server 2014 SP2 and SQL Server 2016, this behavior is controlled by the engine and trace flag 1236 has no effect.",https://support.microsoft.com/help/3024815,Server,Windows,OnPremises,,Warning
|
||||
TF6532,TF 6532 enables performance improvements for Spatial data,Enable trace flag 6532 to enable performance improvements for Spatial data.,"['DefaultRuleset', 'TraceFlag', 'Performance']","Trace Flag 6532 enables performance improvements of query operations with spatial data types.
|
||||
TF6532,TF 6532 enables performance improvements for Spatial data,Enable trace flag 6532 to enable performance improvements for Spatial data.,"['DefaultRuleset', 'TraceFlag', 'Performance']","Trace Flag 6532 enables performance improvements of query operations with spatial data types.
|
||||
The performance gain will vary, depending on the configuration, the types of queries, and the objects.",https://support.microsoft.com/help/3107399,Server,Windows,OnPremises,"['[11.0.6020,11.0.6518)']",Information
|
||||
TF6532.6533,TF 6532 and TF 6533 enable performance improvements for Spatial data,Trace flags 6532 and 6533 do not apply to this SQL Server version. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'Performance']","Trace flags 6532 and 6533 enable performance improvements of query operations with spatial data types.
|
||||
However, this trace flag does not apply to this SQL Server version.
|
||||
TF6532.6533,TF 6532 and TF 6533 enable performance improvements for Spatial data,Trace flags 6532 and 6533 do not apply to this SQL Server version. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'Performance']","Trace flags 6532 and 6533 enable performance improvements of query operations with spatial data types.
|
||||
However, this trace flag does not apply to this SQL Server version.
|
||||
Starting with SQL Server 2016, this behavior is controlled by the engine and trace flags 6532 and 6533 have no effect.",https://support.microsoft.com/help/3107399,Server,Windows,OnPremises,,Warning
|
||||
TF6534,TF 6534 enables performance improvements for Spatial data,Trace flag 6534 does not apply to this SQL Server version. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'Performance']","Trace Flag 6534 enables performance improvement of query operations with spatial data types.
|
||||
However, this trace flag does not apply to this SQL Server version.
|
||||
TF6534,TF 6534 enables performance improvements for Spatial data,Trace flag 6534 does not apply to this SQL Server version. Verify need to set a non-default trace flag with the current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'Performance']","Trace Flag 6534 enables performance improvement of query operations with spatial data types.
|
||||
However, this trace flag does not apply to this SQL Server version.
|
||||
Verify need to set a Non-default trace flag with current system build and configuration.",https://support.microsoft.com/help/3107399,Server,Windows,OnPremises,,Warning
|
||||
TF7412,TF 7412 enables the lightweight profiling infrastructure for live query performance troubleshooting,Enable trace flag 7412 to enables the lightweight profiling infrastructure for live query performance troubleshooting.,"['DefaultRuleset', 'TraceFlag', 'Performance']",Trace Flag 7412 enables the lightweight profiling infrastructure for live query performance troubleshooting. Consider enabling TF 7412 to have the ability to access runtime information on query execution plans for any session.,https://docs.microsoft.com/sql/relational-databases/performance/query-profiling-infrastructure,Server,/^(Windows|Linux)$/,OnPremises,"[13.0.4001,15.0)",Information
|
||||
TF9024,TF 9024 converts a global log pool memory object into NUMA node partitioned memory object.,Verify need to set a Non-default TF with current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'Performance', 'NUMA', 'Memory', 'CPU']",TF9024 converts a global log pool memory object into NUMA node partitioned memory object.,https://support.microsoft.com/help/2809338/fix-high-log-write-waits-counter-value-on-a-sql-server-2012-or-sql-ser,Server,Windows,OnPremises,,Warning
|
||||
TF8048,TF 8048 converts NUMA partitioned memory objects into CPU partitioned,Verify need to set a Non-default TF with current system build and configuration.,"['DefaultRuleset', 'TraceFlag', 'Performance', 'NUMA', 'CPU', 'Memory']",TF 8048 converts NUMA partitioned memory objects into CPU partitioned.,https://support.microsoft.com/en-us/help/2809338/fix-high-log-write-waits-counter-value-on-a-sql-server-2012-or-sql-ser,Server,Windows,OnPremises,,Warning
|
||||
DeprecatedFeatures,Deprecated or discontinued features should not be used,Detected deprecated or discontinued feature uses: @{DeprecatedFeature}. We recommend to replace them with features actual for SQL Server version @{ProductVersion}.,"['DefaultRuleset', 'Deprecated', 'Security', 'UpdateIssues', 'Performance']",This check detects deprecated or discontinued features used on target SQL Server instance. Deprecated features may be removed in a future release of SQL Server. Discontinued features have been removed from specific versions of SQL Server.,https://docs.microsoft.com/sql/relational-databases/performance-monitor/sql-server-deprecated-features-object,Server,/^(Windows|Linux)$/,"OnPremises, ManagedInstance",,Warning
|
||||
SystemHealthSession,system_health XEvent session is not active,Start the session by using the ALTER EVENT SESSION statement or by using the Extended Events node in Object Explorer.,"['DefaultRuleset', 'XEvent', 'SystemHealth']","This session starts automatically when the SQL Server Database Engine starts, and runs without any noticeable performance effects. The session collects system data that you can use to help troubleshoot performance issues in the Database Engine.
|
||||
SystemHealthSession,system_health XEvent session is not active,Start the session by using the ALTER EVENT SESSION statement or by using the Extended Events node in Object Explorer.,"['DefaultRuleset', 'XEvent', 'SystemHealth']","This session starts automatically when the SQL Server Database Engine starts, and runs without any noticeable performance effects. The session collects system data that you can use to help troubleshoot performance issues in the Database Engine.
|
||||
We recommend that you do not stop, alter, or delete the system health session.",https://docs.microsoft.com/sql/relational-databases/extended-events/use-the-system-health-session,Server,/^(Windows|Linux)$/,"OnPremises, ManagedInstance",,Warning
|
||||
SPServerDiagnosticsSession,sp_server_diagnostics xEvent session is not active,Start the session by using the ALTER EVENT SESSION statement or by using the Extended Events node in Object Explorer.,"['DefaultRuleset', 'XEvent', 'SystemHealth']","This session starts automatically when the SQL Server Database Engine starts, and runs without any noticeable performance effects. The session collects system data that you can use to help troubleshoot performance issues in the Database Engine.
|
||||
SPServerDiagnosticsSession,sp_server_diagnostics xEvent session is not active,Start the session by using the ALTER EVENT SESSION statement or by using the Extended Events node in Object Explorer.,"['DefaultRuleset', 'XEvent', 'SystemHealth']","This session starts automatically when the SQL Server Database Engine starts, and runs without any noticeable performance effects. The session collects system data that you can use to help troubleshoot performance issues in the Database Engine.
|
||||
We recommend that you do not stop, alter, or delete the system health session.",https://docs.microsoft.com/sql/relational-databases/system-stored-procedures/sp-server-diagnostics-transact-sql,Server,/^(Windows|Linux)$/,OnPremises,,Warning
|
||||
BlackboxTrace,Blackbox trace is configured and running,Make sure you still need the blackbox trace and stop it otherwise.,"['DefaultRuleset', 'Traces']","This trace is designed to behave similarly to an airplane black box, to help you diagnose intermittent server crashes. It consumes more resources than the default trace and should not be running for extended periods of time.",https://docs.microsoft.com/sql/relational-databases/system-stored-procedures/sp-trace-create-transact-sql,Server,/^(Windows|Linux)$/,OnPremises,,Warning
|
||||
DefaultTrace,No default trace was found or is not active,Make sure that there is enough space for SQL Server to write the default trace file. Then have the default trace run by disabling and re-enabling it.,"['DefaultRuleset', 'Traces']",Default trace provides troubleshooting assistance to database administrators by ensuring that they have the log data necessary to diagnose problems the first time they occur.,https://docs.microsoft.com/sql/relational-databases/policy-based-management/default-trace-log-files-disabled,Server,/^(Windows|Linux)$/,"OnPremises, ManagedInstance",,Warning
|
||||
@@ -127,8 +127,8 @@ PageVerify,PAGE_VERIFY option should be CHECKSUM,Set PAGE_VERIFY option to CHECK
|
||||
DbChaining,Cross-Database Access should be disabled,Set DB_CHAINING option to OFF.,"['DefaultRuleset', 'DBConfiguration', 'Security']",Ownership chaining across databases is turned off by default. Microsoft recommends that you disable cross-database ownership chaining because it exposes you to the additional security risks.,https://docs.microsoft.com/dotnet/framework/data/adonet/sql/enabling-cross-database-access-in-sql-server,Database,/^(Windows|Linux)$/,"OnPremises, ManagedInstance",,Warning
|
||||
AutoCreateStatsIncremental,Incremental option of auto stats should be ON,Set AUTO_CREATE_STATISTICS to ON and set INCREMENTAL to ON,"['DefaultRuleset', 'DBConfiguration', 'Statistics', 'Performance']","Incremental statistics update at partition level is a feature introduced in SQL Server 2014. When the option INCREMENTAL is turn on at the database level, newly auto created column statistics will use incremental statistics on partitioned tables by default.",https://docs.microsoft.com/sql/relational-databases/statistics/statistics,Database,/^(Windows|Linux)$/,"OnPremises, ManagedInstance","[12.0,)",Warning
|
||||
TrustWorthy,TRUSTWORTHY should be OFF,Set TRUSTWORTHY option to OFF,"['DefaultRuleset', 'DBConfiguration', 'Security']","You can use the TRUSTWORTHY database setting to indicate whether the instance of Microsoft SQL Server trusts the database and the contents within the database. By default, this setting is set to OFF to mitigate certain threats that may be present when a database is attached to the server.",https://support.microsoft.com/help/2183687/guidelines-for-using-the-trustworthy-database-setting-in-sql-server,Database,/^(Windows|Linux)$/,OnPremises,,Warning
|
||||
ParameterizationNotSimple,PARAMETERIZATION should be SIMPLE,"Set PARAMETERIZATION = SIMPLE and use forced parameterization only on a certain class of queries, instead of all queries","['DefaultRuleset', 'DBConfiguration', 'Performance', 'QueryOptimizer']","When the PARAMETERIZATION database option is set to SIMPLE, the SQL Server query optimizer may choose to parameterize the queries. This means that any literal values that are contained in a query are substituted with parameters. This process is referred to as simple parameterization. When SIMPLE parameterization is in effect, you cannot control which queries are parameterized and which queries are not. However, you can specify that all queries in a database be parameterized by setting the PARAMETERIZATION database option to FORCED.
|
||||
|
||||
ParameterizationNotSimple,PARAMETERIZATION should be SIMPLE,"Set PARAMETERIZATION = SIMPLE and use forced parameterization only on a certain class of queries, instead of all queries","['DefaultRuleset', 'DBConfiguration', 'Performance', 'QueryOptimizer']","When the PARAMETERIZATION database option is set to SIMPLE, the SQL Server query optimizer may choose to parameterize the queries. This means that any literal values that are contained in a query are substituted with parameters. This process is referred to as simple parameterization. When SIMPLE parameterization is in effect, you cannot control which queries are parameterized and which queries are not. However, you can specify that all queries in a database be parameterized by setting the PARAMETERIZATION database option to FORCED.
|
||||
|
||||
Regardless of whether you have a Plan-Stability or not, SQL Server will always auto parameterize your SQL Statements, and reuse the cached execution plan over and over again. It doesn't matter how terrible the execution plan is. Therefore you have to know in exact detail the shape of your execution plans, and whether they can lead to some performance related problems.",https://docs.microsoft.com/sql/relational-databases/performance/specify-query-parameterization-behavior-by-using-plan-guides,Database,/^(Windows|Linux)$/,"OnPremises, ManagedInstance",,Warning
|
||||
TempDBFilesNotSameSize,TempDB data files are not the same size,Make all TempDB data files the same size,"['DefaultRuleset', 'TempDB', 'Performance', 'DBFileConfiguration']",We recommend that you create all TempDB data files at the same size.,https://support.microsoft.com/kb/2154845,Server,/^(Windows|Linux)$/,OnPremises,,Warning
|
||||
TempDBFilesMultiple4,Number of TempDB data files should be in multiples of 4,Make sure number of TempDB data files is in multiples of 4,"['DefaultRuleset', 'TempDB', 'Performance', 'DBFileConfiguration']","Number of TempDB data files should correlate with the number of (logical) processors on the machine. As a general rule, if the number of logical processors is less than or equal to 8, use the same number of data files as logical processors. If the number of logical processors is greater than 8, use 8 data files and then if contention continues, increase the number of data files by multiples of 4 until the contention is reduced to acceptable levels or make changes to the workload/code.",https://support.microsoft.com/kb/2154845,Server,/^(Windows|Linux)$/,OnPremises,,Warning
|
||||
@@ -152,10 +152,10 @@ AgentAlertsSeverity22,Agent doesn't rise alerts for errors with severity 22,Cons
|
||||
AgentAlertsSeverity23,Agent doesn't rise alerts for errors with severity 23,Consider creating alerts for the following errors: @{error_ids},"['DefaultRuleset', 'Agent']","Events are generated by SQL Server and entered into the Microsoft Windows application log. SQL Server Agent reads the application log and compares events written there to alerts that you have defined. When SQL Server Agent finds a match, it fires an alert, which is an automated response to an event. In addition to monitoring SQL Server events, SQL Server Agent can also monitor performance conditions and Windows Management Instrumentation (WMI) events.",https://docs.microsoft.com/sql/ssms/agent/alerts,Server,Windows,"OnPremises, ManagedInstance",,Warning
|
||||
AgentAlertsSeverity24,Agent doesn't rise alerts for errors with severity 24,Consider creating alerts for the following errors: @{error_ids},"['DefaultRuleset', 'Agent']","Events are generated by SQL Server and entered into the Microsoft Windows application log. SQL Server Agent reads the application log and compares events written there to alerts that you have defined. When SQL Server Agent finds a match, it fires an alert, which is an automated response to an event. In addition to monitoring SQL Server events, SQL Server Agent can also monitor performance conditions and Windows Management Instrumentation (WMI) events.",https://docs.microsoft.com/sql/ssms/agent/alerts,Server,Windows,"OnPremises, ManagedInstance",,Warning
|
||||
WeakPassword,Weak password,Make sure to set strong passwords on the following logins: @{PasswordData},"['DefaultRuleset', 'Security', 'WeakPassword']",Some user logins have weak passwords.,https://docs.microsoft.com/sql/relational-databases/security/strong-passwords,Server,/^(Windows|Linux)$/,"OnPremises, ManagedInstance",,Warning
|
||||
VLFCount,VLF count,Update transaction log settings to reduce the number of VLFs (current number is: @{RecoveryUnitId}),"['DefaultRuleset', 'Backup', 'Performance']","The SQL Server Database Engine divides each physical log file internally into a number of virtual log files (VLFs). Virtual log files have no fixed size, and there is no fixed number of virtual log files for a physical log file. The Database Engine chooses the size of the virtual log files dynamically while it is creating or extending log files. The Database Engine tries to maintain a small number of virtual files. The size of the virtual files after a log file has been extended is the sum of the size of the existing log and the size of the new file increment. The size or number of virtual log files cannot be configured or set by administrators.
|
||||
|
||||
If the log files grow to a large size in many small increments, they will have many virtual log files. This can slow down database startup and also log backup and restore operations. Conversely, if the log files are set to a large size with few or just one increment, they will have few very large virtual log files.
|
||||
|
||||
VLFCount,VLF count,Update transaction log settings to reduce the number of VLFs (current number is: @{RecoveryUnitId}),"['DefaultRuleset', 'Backup', 'Performance']","The SQL Server Database Engine divides each physical log file internally into a number of virtual log files (VLFs). Virtual log files have no fixed size, and there is no fixed number of virtual log files for a physical log file. The Database Engine chooses the size of the virtual log files dynamically while it is creating or extending log files. The Database Engine tries to maintain a small number of virtual files. The size of the virtual files after a log file has been extended is the sum of the size of the existing log and the size of the new file increment. The size or number of virtual log files cannot be configured or set by administrators.
|
||||
|
||||
If the log files grow to a large size in many small increments, they will have many virtual log files. This can slow down database startup and also log backup and restore operations. Conversely, if the log files are set to a large size with few or just one increment, they will have few very large virtual log files.
|
||||
|
||||
We recommend that you assign log files a size value close to the final size required, using the required increments to achieve optimal VLF distribution, and also have a relatively large growth_increment value.",https://docs.microsoft.com/sql/relational-databases/sql-server-transaction-log-architecture-and-management-guide,Database,Windows,"OnPremises, ManagedInstance",,Warning
|
||||
TF8015,TF 8015 disables auto-detection and NUMA setup,Disable trace flag 8015 for this SQL Server instance. This TF does not apply to this SQL Server version,"['DefaultRuleset', 'TraceFlag', 'CPU', 'NUMA']","SQL Server allows you to group CPUs into nodes referred to as soft-NUMA. You usually configure soft-NUMA when you have many CPUs and do not have hardware NUMA, but you can also use soft-NUMA to subdivide hardware NUMA nodes into smaller groups.",https://techcommunity.microsoft.com/t5/SQL-Server-Support/How-It-Works-Soft-NUMA-I-O-Completion-Thread-Lazy-Writer-Workers/ba-p/316044,Server,Windows,OnPremises,"(,11.0.3349)",Warning
|
||||
TF8032,TF 8032 reverts the cache limit parameters to the SQL Server 2005 RTM,The cache limit parameters reverted to the SQL Server 2005 RTM setting but can cause poor performance if large caches make less memory available for other memory consumers like BP,"['DefaultRuleset', 'TraceFlag', 'Performance']",Trace Flag 8032 reverts the cache limit parameters to the SQL Server 2005 RTM setting but can cause poor performance if large caches make less memory available for other memory consumers like BP.,,Server,Windows,OnPremises,"[10.0,)",Warning
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@@ -179,11 +179,11 @@ IndexKeyGuid,Guid in clustered index key column,Get rid of GUIDs in the followin
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IndexesLargeKeys,Indexes keys with more than 900 bytes,Get rid of keys larger than 900 bytes in index @{FullName},"['DefaultRuleset', 'Indexes', 'Performance']","When you design an index that contains many key columns, or large-size columns, calculate the size of the index key to make sure that you do not exceed the maximum index key size. SQL Server retains the 900-byte limit for the maximum total size of all index key columns. This excludes nonkey columns that are included in the definition of nonclustered indexes.",http://msdn.microsoft.com/library/ms191241.aspx,Database,/^(Windows|Linux)$/,"OnPremises, ManagedInstance",,Warning
|
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DisabledIndexes,Disabled Indexes exist,Remove or enable this disabled index: @{FullName},"['DefaultRuleset', 'Indexes', 'Performance']","If you need to load a lot of data quickly, you can disable nonclustered indexes in order to improve performance. After the data load finishes, enable the nonclustered indexes again by rebuilding them. This technique works best in large data warehouse environments where entire dimension tables might be reloaded from scratch every night. Disabling nonclustered indexes is safer than dropping and recreating them because scripting indexes is hard. Unfortunately, sometimes our load processes crash before enabling the indexes again, or sometimes we manually load data and we forget to rebuild them.",https://docs.microsoft.com/sql/relational-databases/indexes/disable-indexes-and-constraints,Database,/^(Windows|Linux)$/,"OnPremises, ManagedInstance",,Warning
|
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IndexesFillFactor,Index fill factor lower 80%,Review index @{FullName} as its fill factor @{FillFactor} is lower than 80 percent,"['DefaultRuleset', 'Indexes', 'Performance']","The fill-factor option is provided for fine-tuning index data storage and performance. When an index is created or rebuilt, the fill-factor value determines the percentage of space on each leaf-level page to be filled with data, reserving the remainder on each page as free space for future growth. For example, specifying a fill-factor value of 80 means that 20 percent of each leaf-level page will be left empty, providing space for index expansion as data is added to the underlying table. The empty space is reserved between the index rows rather than at the end of the index.",https://docs.microsoft.com/sql/relational-databases/indexes/specify-fill-factor-for-an-index,Database,/^(Windows|Linux)$/,"OnPremises, ManagedInstance",,Warning
|
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NonUniqueClusterIndex,Non-unique clustered indexes,Review this clustered index @{FullName} as it is non-unique,"['DefaultRuleset', 'Indexes', 'Performance']","Index uniqueness is highly desirable attribute of a clustering key, and goes hand-in-hand with index narrowness. SQL Server does not require a clustered index to be unique, but yet it must have some means of uniquely identifying every row. That’s why, for non-unique clustered indexes, SQL Server adds to every duplicate instance of a clustering key value a 4-byte integer value called a uniqueifier. This uniqueifier is added everywhere the clustering key is stored. That means the uniqueifier is stored in both clustered and non-clustered indexes. As you can imagine, if there are many rows using the same clustering key value, this can become quite expensive.",https://docs.microsoft.com/sql/relational-databases/indexes/clustered-and-nonclustered-indexes-described,Database,/^(Windows|Linux)$/,"OnPremises, ManagedInstance",,Warning
|
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NonUniqueClusterIndex,Non-unique clustered indexes,Review this clustered index @{FullName} as it is non-unique,"['DefaultRuleset', 'Indexes', 'Performance']","Index uniqueness is highly desirable attribute of a clustering key, and goes hand-in-hand with index narrowness. SQL Server does not require a clustered index to be unique, but yet it must have some means of uniquely identifying every row. Thats why, for non-unique clustered indexes, SQL Server adds to every duplicate instance of a clustering key value a 4-byte integer value called a uniqueifier. This uniqueifier is added everywhere the clustering key is stored. That means the uniqueifier is stored in both clustered and non-clustered indexes. As you can imagine, if there are many rows using the same clustering key value, this can become quite expensive.",https://docs.microsoft.com/sql/relational-databases/indexes/clustered-and-nonclustered-indexes-described,Database,/^(Windows|Linux)$/,"OnPremises, ManagedInstance",,Warning
|
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SuspectPages,Suspect pages,Run DBCC CHECKDB to verify affected database. Suspect pages were found: @{EventType},"['DefaultRuleSet', 'Pages', 'DataIntegrity']","The suspect_pages table is used for maintaining information about suspect pages, and is relevant in helping to decide whether a restore is necessary.",https://docs.microsoft.com/sql/relational-databases/backup-restore/manage-the-suspect-pages-table-sql-server,Database,/^(Windows|Linux)$/,,,Warning
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SparseFiles,Sparse files,Get rid of sparse files: @{SparseFiles},"['DefaultRuleSet', 'Snapshots', 'Backup', 'DataIntegrity']","If the file is sparse or compressed, the NTFS file system may deallocate disk space in the file. This sets the range of bytes to zeroes (0) without extending the file size.","https://blogs.msdn.microsoft.com/jorgepc/2010/11/25/what-are-sparse-files-and-why-should-i-care-as-sql-server-dba/, https://techcommunity.microsoft.com/t5/SQL-Server-Support/Did-your-backup-program-utility-leave-your-SQL-Server-running-in/ba-p/315840",Database,/^(Windows|Linux)$/,,,Warning
|
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TableNoIndex,Tables without indexes,Review table @{TableName} and create reasonable indexes,"['DefaultRuleset', 'Indexes', 'Performance']","Each table in the database has one or more pages. To keep track of those pages, SQL Server uses a special set of pages, called IAM (for Index Allocation Map) pages. In spite of the word “Index” in the name, IAMs are used for non-indexed tables as well. These are called heaps. All the data is there, but the only way to find anything is to read it starting at the beginning. For a very large table, this will be terribly inefficient.",https://docs.microsoft.com/en-us/sql/relational-databases/indexes/heaps-tables-without-clustered-indexes,Database,/^(Windows|Linux)$/,"OnPremises, ManagedInstance",,Warning
|
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TableNoClusteredIndex,Tables without clustered indexes,Review table @{TableName} and consider creating a clustered index,"['DefaultRuleset', 'Indexes', 'Performance']","Tables without clustered indexes are called heaps. They’re scattered on disk anywhere that SQL Server can find a spot, and they’re not stored in any order whatsoever. This can make for really fast inserts – SQL Server can just throw the data down – but slow selects, updates, and deletes.",https://docs.microsoft.com/en-us/sql/relational-databases/indexes/heaps-tables-without-clustered-indexes,Database,/^(Windows|Linux)$/,"OnPremises, ManagedInstance",,Warning
|
||||
TableNoIndex,Tables without indexes,Review table @{TableName} and create reasonable indexes,"['DefaultRuleset', 'Indexes', 'Performance']","Each table in the database has one or more pages. To keep track of those pages, SQL Server uses a special set of pages, called IAM (for Index Allocation Map) pages. In spite of the word Index in the name, IAMs are used for non-indexed tables as well. These are called heaps. All the data is there, but the only way to find anything is to read it starting at the beginning. For a very large table, this will be terribly inefficient.",https://docs.microsoft.com/en-us/sql/relational-databases/indexes/heaps-tables-without-clustered-indexes,Database,/^(Windows|Linux)$/,"OnPremises, ManagedInstance",,Warning
|
||||
TableNoClusteredIndex,Tables without clustered indexes,Review table @{TableName} and consider creating a clustered index,"['DefaultRuleset', 'Indexes', 'Performance']","Tables without clustered indexes are called heaps. Theyre scattered on disk anywhere that SQL Server can find a spot, and theyre not stored in any order whatsoever. This can make for really fast inserts SQL Server can just throw the data down but slow selects, updates, and deletes.",https://docs.microsoft.com/en-us/sql/relational-databases/indexes/heaps-tables-without-clustered-indexes,Database,/^(Windows|Linux)$/,"OnPremises, ManagedInstance",,Warning
|
||||
TablePSAlign,Table index not aligned with PS,Consider recreating index @{IndexName} in table @{TableName} to have it aligned with your schema,"['DefaultRuleset', 'Indexes', 'Performance']","Table partitioning is a complex way to break out your large tables into smaller, more manageable chunks, but it comes with a lot of management heartache. One of the challenges is making sure that your indexes are partitioned and aligned the same way as your clustered index.",https://docs.microsoft.com/sql/relational-databases/partitions/partitioned-tables-and-indexes,Database,/^(Windows|Linux)$/,"OnPremises, ManagedInstance",,Warning
|
||||
LoginNoPassword,Logins with no passwords,Make sure to set strong passwords on the following logins: @{PasswordData},"['DefaultRuleset', 'Security', 'WeakPassword']",Password complexity policies are designed to deter brute force attacks by increasing the number of possible passwords.,https://docs.microsoft.com/sql/relational-databases/security/password-policy,Server,/^(Windows|Linux)$/,"OnPremises, ManagedInstance",,Warning
|
||||
LoginEqPassword,Logins with passwords that are same as the login names,Please review logins with password equals to login: @{PasswordData},"['DefaultRuleset', 'Security', 'WeakPassword']",Password complexity policies are designed to deter brute force attacks by increasing the number of possible passwords.,https://docs.microsoft.com/sql/relational-databases/security/password-policy,Server,/^(Windows|Linux)$/,"OnPremises, ManagedInstance",,Warning
|
||||
@@ -191,3 +191,4 @@ SystemHealth,System Health important messages,Error @{Error_Number} has occured
|
||||
RarelyUsedIndex,Rarely used index,Make sure you need index @{IndexName} as it's used too rarely,"['DefaultRuleset', 'Indexes', 'Performance']","Rarely used indexes can slow down database's performance. Time of write operations is increased because of index maintenance, but index is not used quite often. It makes sense to compare impact of writing operations versus rare reading speedup.",https://docs.microsoft.com/sql/t-sql/statements/drop-index-transact-sql,Database,/^(Windows|Linux)$/,"OnPremises, ManagedInstance",,Warning
|
||||
UnusedIndex,Unused index,Make sure you need index @{IndexName} as it's unused,"['DefaultRuleset', 'Index', 'Performance']","Unused indexes can slow down database's performance. Time of write operations is increased because of index maintenance, but index is not used anywhere.",https://docs.microsoft.com/sql/t-sql/statements/drop-index-transact-sql,Database,/^(Windows|Linux)$/,"OnPremises, ManagedInstance",,Warning
|
||||
SkewedCompatibilityLevel,Database with skewed compatibility level,Update database compatibility level (current level: @{CompatibilityLevel}),"['DefaultRuleset', 'CompatibilityLevel', 'Security', 'Performance', 'UpdateIssues']",Some databases may have a compatibility level lower than the allowed level by the Database Engine.,https://docs.microsoft.com/sql/t-sql/statements/alter-database-transact-sql-compatibility-level,Database,/^(Windows|Linux)$/,,,Warning
|
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|
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|
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|
Reference in New Issue
Block a user