Sql updating table from temp table

Creation of memory-optimized tables takes longer than creation of traditional tables, due to the compile-time optimizations.Creating and dropping memory-optimized tables as part of the online workload would impact the performance of the workload, as well as the performance of redo on Always On secondaries and database recovery.Since temporary tables can be seen anywhere in a user session, this can be exploited to help you modularize your application code.For example, the following stored procedure generates DDL to update all statistics in the database by statistic name.Suppose you have the following global temporary table.The preparations for replacing a session temporary table involve more T-SQL than for the earlier global temporary table scenario.Temporary tables are created by prefixing your table name with a CREATE TABLE #stats_ddl ( [schema_name] NVARCHAR(128) NOT NULL , [table_name] NVARCHAR(128) NOT NULL , [stats_name] NVARCHAR(128) NOT NULL , [stats_is_filtered] BIT NOT NULL , [seq_nmbr] BIGINT NOT NULL , [two_part_name] NVARCHAR(260) NOT NULL , [three_part_name] NVARCHAR(400) NOT NULL ) WITH ( DISTRIBUTION = HASH([seq_nmbr]) , HEAP ) CREATE TABLE #stats_ddl WITH ( DISTRIBUTION = HASH([seq_nmbr]) , HEAP ) AS ( SELECT sm.[name] AS [schema_name] , tb.[name] AS [table_name] , st.[name] AS [stats_name] , st.[has_filter] AS [stats_is_filtered] , ROW_NUMBER() OVER(ORDER BY (SELECT NULL)) AS [seq_nmbr] , QUOTENAME(sm.[name]) '.' QUOTENAME(tb.[name]) AS [two_part_name] , QUOTENAME(DB_NAME()) '.' QUOTENAME(sm.[name]) '.' QUOTENAME(tb.[name]) AS [three_part_name] FROM sys.objects AS ob JOIN sys.stats AS st ON ob.[object_id] = st.[object_id] JOIN sys.stats_columns AS sc ON st.[stats_id] = sc.[stats_id] AND st.[object_id] = sc.[object_id] JOIN sys.columns AS co ON sc.[column_id] = co.[column_id] AND sc.[object_id] = co.[object_id] JOIN sys.tables AS tb ON co.[object_id] = tb.[object_id] JOIN sys.schemas AS sm ON tb.[schema_id] = sm.[schema_id] WHERE 1=1 AND st.[user_created] = 1 GROUP BY sm.[name] , tb.[name] , st.[name] , st.[filter_definition] , st.[has_filter] ) SELECT CASE @update_type WHEN 1 THEN ' UPDATE STATISTICS ' [two_part_name] '(' [stats_name] ');' WHEN 2 THEN ' UPDATE STATISTICS ' [two_part_name] '(' [stats_name] ') WITH FULLSCAN;' WHEN 3 THEN ' UPDATE STATISTICS ' [two_part_name] '(' [stats_name] ') WITH SAMPLE ' CAST(@sample_pct AS VARCHAR(20)) ' PERCENT;' WHEN 4 THEN ' UPDATE STATISTICS ' [two_part_name] '(' [stats_name] ') WITH RESAMPLE;' END AS [update_stats_ddl] , [seq_nmbr] FROM t1 ; to remove temporary tables when you have finished with them in your code.

----'; DROP TYPE IF EXISTS Table C_mem; go CREATE TYPE Table C_mem -- !! AS TABLE ( Column1 INT NOT NULL INDEX ix1, Column2 CHAR(10) ) WITH (MEMORY_OPTIMIZED = ON); go DECLARE @date String_Begin nvarchar(64) = Convert(nvarchar(64), Get Utc Date(), 121); PRINT Concat(@date String_Begin, ' = Begin time, _mem.'); go SET No Count ON; DECLARE @tv Table C Table C_mem; -- !!Temporary tables offer a performance benefit because their results are written to local rather than remote storage.Temporary tables are slightly different in Azure SQL Data Warehouse than Azure SQL Database as they can be accessed from anywhere inside the session, including both inside and outside of a stored procedure.Its scope ends when either the batch or the session ends.The TYPE definition created by the first go-delimited batch persists even after the server is shutdown and restarted.INSERT INTO @tv Table C (Column1) values (1), (2); INSERT INTO @tv Table C (Column1) values (3), (4); DELETE @tv Table C; GO 5001 DECLARE @date String_End nvarchar(64) = Convert(nvarchar(64), Get Utc Date(), 121); PRINT Concat(@date String_End, ' = End time, _mem.'); go DROP TYPE IF EXISTS Table C_mem; go ---- End memory-optimized. The larger the row count and the index key, the more the difference increases.------------------------------------------------- ---- Start traditional on-disk. PRINT ' '; PRINT '---- Next, tempdb based, slower. If the memory-optimized table variable is accessed only with one exact key value per access, a hash index might be a better choice than a nonclustered index.----'; go /*** Actual output, SQL Server 2016: ---- Next, memory-optimized, faster. Beginning execution loop Batch execution completed 5001 times. For more information on the upcoming change, we invite you to read our blog post.This article contains essential guidance for using temporary tables and highlights the principles of session level temporary tables.----'; DROP TYPE IF EXISTS Table C_tempdb; go CREATE TYPE Table C_tempdb -- !! AS TABLE ( Column1 INT NOT NULL , Column2 CHAR(10) ); go DECLARE @date String_Begin nvarchar(64) = Convert(nvarchar(64), Get Utc Date(), 121); PRINT Concat(@date String_Begin, ' = Begin time, _tempdb.'); go SET No Count ON; DECLARE @tv Table C Table C_tempdb; -- !! Beginning execution loop Batch execution completed 5001 times. However, if you cannot estimate the appropriate BUCKET_COUNT, a NONCLUSTERED index is a good second choice.INSERT INTO @tv Table C (Column1) values (1), (2); INSERT INTO @tv Table C (Column1) values (3), (4); DELETE @tv Table C; GO 5001 DECLARE @date String_End nvarchar(64) = Convert(nvarchar(64), Get Utc Date(), 121); PRINT Concat(@date String_End, ' = End time, _tempdb.'); go DROP TYPE IF EXISTS Table C_tempdb; go ---- PRINT '---- Tests done. Note The feedback system for this content will be changing soon. If content within a comment thread is important to you, please save a copy.

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