TAILIEUCHUNG - SQL Server Tacklebox- P28

SQL Server Tacklebox- P28: This book, as with almost all books, started out as an idea. I wanted to accumulate together those scripts and tools that I have built over the years so that DBAs could sort through them and perhaps adapt them for their own circumstances. | 5 DBA as detective . Executing. .ster sa 56 sp lock E7 1 n Results Messages spid dbid bpd Indld Type Resource Mode Status 1 51 5 708577566 0 RID 1 173 24 X GRANT 2 51 5 708577566 0 PAG 1 173 IX GRANT 3 51 5 708577566 0 RID 1 175 24 X GRANT 4 51 5 708577566 0 RID 1 173 16 X GRANT 5 51 5 708577566 0 RID 1 175 16 X GRANT e 51 5 708577566 0 RID 1 175 40 X GRANT 7 51 5 708577566 0 RID 1 173 32 X GRANT 8 51 5 708577566 0 RID 1 175 32 X GRANT 8 51 5 708577566 0 RID 1 175 56 X GRANT 10 51 5 708577566 0 RID 1 175 48 X GRANT 11 51 5 708577566 0 RID 1 175 65 X GRANT 12 51 5 708577566 0 RID 1 173 8 X GRANT 13 51 5 708577566 0 RID 1 175 8 X GRANT 14 51 5 708577566 0 RID 1 173 1 X GRANT 15 51 5 708577566 0 RID 1 175 1 X GRANT 16 51 5 708577566 0 RID 1 173 25 X GRANT Figure Number of locks from Bad Query. You can see that there are many locks acquired mostly exclusive locks at the row level as indicated by the mode X and the type RID . When I see one SPID that has acquired this number of locks especially exclusive locks I get very concerned that something is definitely not as it should be. Often a simple count of the locks and more importantly the types of locks for a specific SPID is enough to help me locate a poorly performing query even if there is no obvious blocking. Acquiring locks just like acquiring connections requires memory resources and even shared locks which may not block others from accessing data can sometimes have a major performance impact due to memory or other resource pressures. 135 5 DBA as detective Automating discovery of problems Up to this point we have used sp_who2 to seek out SPIDs that are causing blocking issues dbcc inputbuffer to elicit the SQL being executed by such a blocking SPID and then sp_lock to discover some information about the locks being acquired by the offending process. All of this took quite a bit of time to manually discover and resolve and when a query is locking out an entire table and depleting .

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