Consider also logging and how you can affect it.īut the worst thing in your article is that you didn't clear the cache before you run SELECT INTO. You can have parallel INSERT SELECT with TABLOCK (of course it depends of SQL Server version) and you should compare these two constructs using MAXDOP 1 and more than 1 as a separate tests. Performance depends on a lot of factors - your SELECT INTO run in parallel and INSERT SELECT run in serial. SQL Server INSERT INTO ExampleĬPU will increase when query uses many cores. Temporary tables when we insert a large number of rows. Is large then we can experience poor query performance. Data is inserted quickly in the temporary table, but if the amount of data Generally speaking, the performance of both options are similar for a small amount Temporary tables can be created in two ways: Reuse the earlier pages, which reduces the number of page modifications required. When the table is created later, SQL Server will
With temporary tableĬaching, SQL Server will not drop the table physically, but will truncate it and In buffer pool as compared to permanent disk based tables. The TempDB allocation map pages (IAM, SGAM and PES). Maintains statistics for temporary tables.Ĭreation and deletion of temporary tables requires access and modification of Will be dropped automatically when the session disconnects. We can drop the temporary table using the DROP TABLE command or the temporary table These tables are visible and accessible within the session only. Temporary tablesĪre stored in the TempDB database with a unique object name and created on a connection These objects will be created in the TempDB system database. You need to add prefix '#' for local temporary tables and '#' for global temporary SQL Server includes the two options for temporary tables:
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