Question

I installed SQL Server 2012, and attached a database originally generated by SQL Server 2008 R2.

Everything appeared to work perfectly, with one problem: merges dropped from 1000 per second to 10 per second (a 100x slowdown).

I’m surmising that its because I am accessing a SQL Server 2008 R2 database from SQL Server 2012. Is there some way to convert the database to SQL Server 2012 format? Or is there something else thats going on that might explain the 100x slowdown in performance?

Answer 1

Please make sure that you set the compatibility mode of the database to 110, and update statistics.

ALTER DATABASE MyDatabase SET COMPATIBILITY_LEVEL = 110;

DECLARE @sql NVARCHAR(MAX) = N'';

SELECT @sql += CHAR(13) + CHAR(10) + 'UPDATE STATISTICS '
  + QUOTENAME(SCHEMA_NAME(schema_id)) 
  + '.' + QUOTENAME(name) + ' WITH FULLSCAN;'
  FROM sys.tables;

PRINT @sql;
--EXEC sp_executesql @sql;