Hash warnings (last hour)

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Rating: 3.0/5 (3 votes cast)
16,184 0 ,
This metric measures the number of hash warnings events in the last hour. A hash warning event means that part of the data processed for a hash operation was written to tempdb. Read more

Processes in a runnable state (worker query)

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Rating: 0.0/5 (0 votes cast)
9,698 1
This metric measures the load of running processes within SQL Server. It doesn’t show any specific problems, but can act as a measure of the pressure being put on your SQL Server instance. Read more

Out of memory errors

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Rating: 5.0/5 (2 votes cast)
13,456 0 , ,
The number of out of memory errors that have occurred within a rolling five minute window. If you just want to keep an eye out for any memory errors, you can watch the ring buffers for the Out of Memory error alert when it gets registered there. Read more

Buffer pressure

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Rating: 4.0/5 (5 votes cast)
18,487 1 , ,
Trying to determine if you have pressure in your buffer allocations can be difficult. Buffer cache hit ratio is an almost useless metric, so you need a mechanism to let you know if there’s a problem in that area. Read more

Ad hoc query stubs in plan cache

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Rating: 4.0/5 (1 vote cast)
10,893 0 ,
This metric measures the total number of one-time use ad hoc queries in the plan cache that have been stored in the form of a stub, not as a full execution plan. Read more

WriteLog wait time

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Rating: 5.0/5 (2 votes cast)
27,899 0 ,
During a transaction, data is written to the log cache so that it’s ready to be written to the log file on commit, or can be rolled back if necessary. When the log cache is being flushed to disk, the SQL Server session will wait on the WriteLog wait type. Read more