SQL Server – Finding Parent Source from T-SQL Snippet

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The question:

The environments for which I’m responsible have some pretty substantial plan non-reuse challenges. I’ve run across the following query (h/t Brent Ozar blog commenter Michael J Swart) that does a fine job of itemizing the worst offenders:

WITH cte AS (
   SELECT COUNT(*) [count], query_hash, min(sql_handle) [sql_handle_example]
   FROM sys.dm_exec_query_stats
   GROUP BY query_hash
   )
SELECT cte.*, t.text [query_text_example]
FROM cte
CROSS APPLY sys.dm_exec_sql_text(sql_handle_example) t
WHERE [count] > 100
ORDER BY [count] DESC

My challenge is taking a snip of the [query_text_example] text and efficiently identifying whether it’s originating from a sproc, and if so which one in which database. I’ve done some Googling and testing and it’s been puzzlingly difficult to find a solution that takes a snippet of query text, whether it was dynamically built or not, and accurately identifies its parent sproc. Does anyone have any suggestions?

The Solutions:

Below are the methods you can try. The first solution is probably the best. Try others if the first one doesn’t work. Senior developers aren’t just copying/pasting – they read the methods carefully & apply them wisely to each case.

Method 1

parental advisory

You can use the dm_exec_procedure_stats view, and if you’re on SQL Server 2016 or better, the dm_exec_function_stats view as well, to track down scalar UDFs.

Both of those views have an object_id column that can be used to resolve procedure and function names with the OBJECT_NAME function. You can match those to various other views on the sql_handle or plan_handle column.

Unless you are doing this scoped to a single database that you care about, you may also need to use the dm_exec_plan_attributes view to grab the dbid attribute, which can be used as a second argument in OBJECT_NAME.

Method 2

dm_exec_sql_text supplies a objectid column which is NULL for ad-hoc batches. You can just left-join it with sys.objects

WITH cte AS (
    SELECT
      COUNT(*) [count],
      s.query_hash,
      min(s.sql_handle) [sql_handle_example]
    FROM sys.dm_exec_query_stats s
    GROUP BY s.query_hash
    HAVING count(*) > 100
)
SELECT
  cte.*,
  t.text [query_text_example],
  o.name
FROM cte
CROSS APPLY sys.dm_exec_sql_text(cte.sql_handle_example) t
LEFT JOIN sys.objects o ON o.object_id = t.objectid
ORDER BY [count] DESC;

This only works for a single database. To join it across multiple unknown databases you need dynamic SQL. Each database has a separate sys.objects.


All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0

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