We are developing an application that (very simply put) will copy data from many local databases to one central. In this process lots of rows gets inserted to a temporary table. This temporary table is later used to check which rows are up to date, which rows should be deleted and which rows needs to be updated.
In a current test we noticed a huge performance difference when populating the temporary table. If we had a global temporary table it took about 3 minutes to populate the table with 700,000 rows. If we had a local temporary table, the same task took 9 minutes.
The only difference between the questions are that # gets switched to ##.
We've tested on two different SQL Server Std 2005 running on different hardware with the same result.
Microsoft SQL Server 2005 - 9.00.3159.00 (Intel X86) Mar 23 2007 16:15:11 Copyright (c) 1988-2005 Microsoft Corporation Developer Edition on Windows NT 5.2 (Build 3790: Service Pack 2)
Microsoft SQL Server 2005 - 9.00.3233.00 (X64) Mar 6 2008 21:58:47 Copyright (c) 1988-2005 Microsoft Corporation Standard Edition (64-bit) on Windows NT 5.2 (Build 3790: Service Pack 2)
Can anyone explain the differnce in performance?
If the performance gap is expected, would you recommend us to convert to global temp tables considering that under peak we will have 30-40 sessions doing synchronizations at the same time? Each temporary table is crated with a unique guid as a name.
CREATE TABLE #3ILRRRF920M64UVI (
INSERT INTO #3ILRRRF920M64UVI VALUES( 'CFil', '2TKJQLNEV1PKK1P1', '2000-08-28 16:22:18.000', NULL )
INSERT INTO #3ILRRRF920M64UVI VALUES( 'CFil', '34DLCD7S0E0JFGDB', '2005-01-22 21:36:53.000', NULL )
... another 700.000 times...
CREATE INDEX Tmp_IGUID ON #3ILRRRF920M64UVI ([GUID])