Add database debug hint in development doc
What does this MR do?
In development docs page, under the section: https://docs.gitlab.com/ee/development/#debugging ,
add a link on how to use Verbose Query Logs in rails console to trace
the source of SQL query. It is useful hint for debugging and identifying
performance problems.
It will looks like:
Tracing the source of an SQL query in rails console using Verbose Query Logs
Related issues
No issue for this simple change.
But a little bit background: during performance improvement analysis for issue #39112 (closed), I identified some SQL queries as improvement candidates. However it is not easy to position the source code where these SQL are generated from.
I have tried https://docs.gitlab.com/ee/development/database_query_comments.html which is in the same debugging section on development doc https://docs.gitlab.com/ee/development/README.html#debugging. And I found it is not easy to work for Rails console(with complex code, it give stack level too deep error).
While Verbose Query Logs works very well in Rails console, so it is worth to add this information so other developers can refer to. It seems not many people know it.
Author's checklist
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Follow the Documentation Guidelines and Style Guide. -
If applicable, update the permissions table. -
Link docs to and from the higher-level index page, plus other related docs where helpful. -
Apply the documentation label.
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