Files
sql-server-samples/samples/features/intelligent-query-processing/IQP Demo - Row Mode MGF.sql
T
2020-02-07 11:19:29 -08:00

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Transact-SQL

-- ******************************************************** --
-- Row mode memory grant feedback
-- See https://aka.ms/IQP for more background
-- Demo scripts: https://aka.ms/IQPDemos
-- This demo is on SQL Server 2019 and Azure SQL DB
-- SSMS v17.9 or higher
-- Email IntelligentQP@microsoft.com for questions\feedback
-- ******************************************************** --
USE [master];
GO
ALTER DATABASE [WideWorldImportersDW] SET COMPATIBILITY_LEVEL = 150;
GO
ALTER DATABASE SCOPED CONFIGURATION CLEAR PROCEDURE_CACHE;
GO
USE [WideWorldImportersDW];
GO
-- Simulate out-of-date stats
UPDATE STATISTICS Fact.OrderHistory
WITH ROWCOUNT = 1;
GO
-- Include actual execution plan
-- Execute once to see spills (row mode)
-- Execute a second time to see correction
SELECT fo.[Order Key], fo.Description,
si.[Lead Time Days]
FROM Fact.OrderHistory AS fo
INNER HASH JOIN Dimension.[Stock Item] AS si
ON fo.[Stock Item Key] = si.[Stock Item Key]
WHERE fo.[Lineage Key] = 9
AND si.[Lead Time Days] > 19;
-- Cleanup
UPDATE STATISTICS Fact.OrderHistory
WITH ROWCOUNT = 3702672;
GO