MAX_GRANT_PERCENT

Jack Li gives an example in which MAX_GRANT_PERCENT can keep certain queries from getting runaway memory grants:

The customer has lots of waits on RESOURCE_SEMAPHORE_QUERY_COMPILE.  To troubleshoot this, we have to look from two angles.  First, did customer have many queries needing large amount of compile memory?  Secondly, was it possible that other components used too much memory, causing the threshold lowered?  In other words, if SQL Server had enough memory, those queries requiring same amount of compile memory would not have been put to wait.

We used this query and captured for several iterations of data to confirm that server didn’t have queries that required large amount of compile memory per se.

It’s nice to have this trick up your sleeve when you simply can’t get a better query in place.

Related Posts

What Prevents Plan Reuse?

Eric Blinn walks us through what might cause a query plan not to be used: There are several reasons that a query plan would need to be compiled again, but they can be boiled down to a few popular reasons. The first one is simple.  The plan cache is stored exclusively in memory.  If there […]

Read More

Capturing UDF CPU Times

Jonathan Kehayias notes an improvement in recent versions of SQL Server: Microsoft has been enhancing the contents of the ShowplanXML output for SQL Server over the last few releases and in SQL Server 2017 CU3, they introduced user-defined function (UDF) execution statistics into the QueryTimeStats node of the XML output. This was also back ported to SQL Server […]

Read More

Categories

June 2016
MTWTFSS
« May Jul »
 12345
6789101112
13141516171819
20212223242526
27282930