sp_BlitzFirst SET LOCK_TIMEOUT

[sqlslinger]

SET LOCK_TIMEOUT 1000 when APPLY sys.dm_exec_query_statistics_xml to prevent mutex issues. Set GitHub #3210

[BrentOzar]

Errr, that can't work. This puts SET LOCK_TIMEOUT in the middle of a query. Note what happens next in the query - it's an outer apply. That won't even compile.

You can see what I mean by trying to run:

SELECT * FROM sys.databases d
SET LOCK_TIMEOUT 1000
OUTER APPLY sys.dm_exec_query_statistics_xml(d.database_id) qs_live;

That doesn't even parse. So... with all due respect, I don't think you understand the problem you're trying to solve, so let's call this one off.

[sqlslinger]

@BrentOzar,

Can you please reopen this issue, or comment on my response?

Brent,

Are you sure? Look again. I added the SET LOCK_TIMEOUT 1000 before the
existing @StringToExecute, for exactly the reason that it already had data
in it.

So if @StringToExecute contained 'SELECT * FROM sys.databases d', the
result of the statement would be

SET LOCK_TIMEOUT 1000
SELECT * FROM sys.databases d
OUTER APPLY sys.dm_exec_query_statistics_xml(d.database_id) qs_live;

As I said, this is compiled and working.

Vince

[sqlslinger]

Brent, Are you sure? Look again. I added the SET LOCK_TIMEOUT 1000 *before* the existing @StringToExecute, for exactly the reason that it already had data in it. So if @StringToExecute contained 'SELECT * FROM sys.databases d', the result of the statement would be SET LOCK_TIMEOUT 1000 SELECT * FROM sys.databases d OUTER APPLY sys.dm_exec_query_statistics_xml(d.database_id) qs_live; As I said, this is compiled and working. Vince

…

On Tue, Jan 31, 2023 at 9:11 AM Brent Ozar ***@***.***> wrote: ***@***.**** commented on this pull request. ------------------------------ In sp_BlitzFirst.sql <#3221 (comment)> : > @@ -2293,8 +2293,9 @@ If one of them is a lead blocker, consider killing that query.'' AS HowToStopit, CROSS APPLY sys.dm_exec_query_plan(r.plan_handle) AS qp '; IF EXISTS (SELECT * FROM sys.all_objects WHERE name = 'dm_exec_query_statistics_xml') - SET @StringToExecute = @StringToExecute + N' OUTER APPLY sys.dm_exec_query_statistics_xml(s.session_id) qs_live '; - + /* GitHub #3210 */ + SET @StringToExecute = N' + SET LOCK_TIMEOUT 1000 ' + @StringToExecute + N' OUTER APPLY sys.dm_exec_query_statistics_xml(s.session_id) qs_live '; Errr, that can't work. This puts SET LOCK_TIMEOUT in the middle of a query. Note what happens next in the query - it's an outer apply. That won't even compile. You can see what I mean by trying to run: SELECT * FROM sys.databases d SET LOCK_TIMEOUT 1000 OUTER APPLY sys.dm_exec_query_statistics_xml(d.database_id) qs_live; That doesn't even parse. So... with all due respect, I don't think you understand the problem you're trying to solve, so let's call this one off. — Reply to this email directly, view it on GitHub <#3221 (review)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/APNFWAUTV2CKOB5I6ARJZADWVEMSVANCNFSM6AAAAAAULPAZFM> . You are receiving this because you authored the thread.Message ID: <BrentOzarULTD/SQL-Server-First-Responder-Kit/pull/3221/review/1277270261@ github.com>

[BrentOzar]

Sorry about that! I misunderstood the code. Just a gentle suggestion for next time - comments sure do help when folks are trying to understand your code. ;-)

[BrentOzar]

Sorry about that! I misunderstood the code. Just a gentle suggestion for next time - comments sure do help when folks are trying to understand your code. ;-)