Or can it be that this "very complex, multi-million-row operation" run in parallel and the head thread stayed "Runnable" while child threads were actually running tasks?
Please do not get me wrong, I only trying to learn from you. I is impossible to see it in running state since it should run in few mkseconds. So right now I try to learn more about spinlock contention since this is the only lead I have left.
Don't know if it's a bug, or if some piece of it was "runnable", while other pieces were "running", and it showed as "runnable" because of that. Lokesh Vij. Runnable is fine If this is not the case then your query is working. You must be logged in to reply to this topic. Login to reply. Post reply. July 16, at am Hi, I see one SPID hanging for up to 20 minutes with status "Runnable" and blocking others that wait for executing same application flow.
Please share your ideas Either way, it makes sense. Thanks for clarification, I got it. It does do some locking. It showed user queries being blocked by the update statistics SPID. Typically fullscan is used in maintenance plans that are run off hours.
SQL Server does update stats automatically by default, but there are reasons to update them in your maintenance scripts that the auto update doesn't cover.
If you want to run update statistics while your DB is busy, on a large table avoid using fullscan and just let SQL Server choose the default sample size. I noticed the current marked answer states it does not block. Be careful about following that advice.
Not exactly. Sign in. United States English. Ask a question. You as the SQL Server DBA decide that updating database statistics is one possible solution to the problem, but your boss says that it will cause blocking and advises not to update statistics while the database is being used. In this tip I show that doing a statistics update does not cause blocking. Some people say that a statistics update blocks transactional activity. They say that the performance of the application running on top of SQL Server runs slower when the statistics are being updated, but there may be other reasons that may degrade performance like the intense disk activity produced when updating statistics.
In this tip, we will cover a scenario where we update statistics while the database is being used to see if blocking does occur during the statistics update. Please consider that you should add enough data that gives you time when running the statistics update to run Dynamic Management View queries in another session to see what is occurring. While the statistics update is running, open a new session and execute the following query against sys. The following image is a screen capture of the output of the previous query in my test environment.
In order to analyze the previous query results, I included a short version of the table available from MSDN with the description of the sys. Represents the resource type.
Acquiring a subtype lock without holding a nonsubtyped lock of the parent type is technically valid. Different subtypes do not conflict with each other or with the nonsubtyped parent type. Not all resource types have subtypes. Description of the resource that contains only information that is not available from other resource columns.
ID of the entity in a database with which a resource is associated. Mode of the request. For granted requests, this is the granted mode; for waiting requests, this is the mode being requested.
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