Fault-finding unexpected data changes

  • We have an established ASP.NET application and SQL Server database in production, and have observed a "status" (integer ID value) in a particular user table changing value, then reverting back, before changing to the original value again, all within a few milliseconds.

    There are triggers on the table, and a good amount of code around this area. But there is no obvious culprit.

    What I am trying to establish is, "what is causing the status to oscillate in this way?", as looking at the code it shouldn't be doing so.

    We have considered writing @@NESTLEVEL to a table in particular objects, but this doesn't really give us insight as to what is causing the oscillation in status.

    How else might we best fault-find this?

  • Cascading triggers?

    --Jeff Moden


    RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
    First step towards the paradigm shift of writing Set Based code:
    ________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

    Change is inevitable... Change for the better is not.


    Helpful Links:
    How to post code problems
    How to Post Performance Problems
    Create a Tally Function (fnTally)

  • Could well be...

    I have created an Extended Event session to try to capture what's going on.

    -- Create new Extended Event session.
    CREATE EVENT SESSION [StatusChanges] ON SERVER
    ADD EVENT sqlserver.sp_statement_completed
    (
    SET collect_object_name = (1), collect_statement = (1)
    ACTION (sqlserver.database_name, sqlserver.server_principal_name, sqlserver.sql_text)
    WHERE
    (
    [sqlserver].[equal_i_sql_unicode_string] ([sqlserver].[database_name], N'MyDatabase') AND
    [sqlserver].[like_i_sql_unicode_string] ([statement], N'%UPDATE%P%SET%Status%=%')
    )
    )
    ADD TARGET package0.event_file (SET filename = N'C:\Temp\StatusChanges.xel', max_file_size=(100))
    WITH
    (
    MAX_MEMORY = 4096 KB,
    EVENT_RETENTION_MODE = ALLOW_SINGLE_EVENT_LOSS,
    MAX_DISPATCH_LATENCY = 30 SECONDS,
    MAX_EVENT_SIZE = 0 KB,
    MEMORY_PARTITION_MODE = NONE,
    TRACK_CAUSALITY = ON,
    STARTUP_STATE = ON
    );
    GO

    • This reply was modified 2 years, 1 month ago by  zoggling.

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