Limitations In sys.dm_exec_query_plan

Brent Ozar shows a limitation in the sys.dm_exec_query_plan DMV:

The query with six joins has a cached plan that you can click on – because it’s from sys.dm_exec_query_plan, a management object that returns execution plans as XML.

The query with seven joins does not. Its cached plan is too large or complex for that DMV. Microsoft quickly realized this problem when 2005 came out, so in 2005 Service Pack 2, they introduced sys.dm_exec_text_query_plan. That function returns bigger data – but it only comes back in text format.

There are a couple of workarounds, at least, but they aren’t ideal.

Related Posts

VLFs: How Many Are Too Many?

Randolph West looks at a baseline for the maximum number of Virtual Log Files for a database: In a transaction log with too many or too few VLFs we might experience performance issues under a normal workload, as well as during the backup and restore process. So what is the “right” amount? In customer engagements, I follow a […]

Read More

dbachecks Improvements

Rob Sewell shows off some improvements in the dbachecks library: With the latest release of dbachecks we have added a new check for testing that foreign keys and constraints are trusted thanks to Cláudio Silva b | t To get the latest release you will need to run 1 Update-Module dbachecks You should do this regularly as we release new improvements […]

Read More

Categories

June 2017
MTWTFSS
« May Jul »
 1234
567891011
12131415161718
19202122232425
2627282930