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Diffstat (limited to 'doc/development/merge_request_performance_guidelines.md')
| -rw-r--r-- | doc/development/merge_request_performance_guidelines.md | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/doc/development/merge_request_performance_guidelines.md b/doc/development/merge_request_performance_guidelines.md index 8232a0a113c..2b4126b43ef 100644 --- a/doc/development/merge_request_performance_guidelines.md +++ b/doc/development/merge_request_performance_guidelines.md @@ -68,7 +68,7 @@ end This will end up running one query for every object to update. This code can easily overload a database given enough rows to update or many instances of this code running in parallel. This particular problem is known as the -["N+1 query problem"](http://guides.rubyonrails.org/active_record_querying.html#eager-loading-associations). +["N+1 query problem"](http://guides.rubyonrails.org/active_record_querying.html#eager-loading-associations). You can write a test with [QueryRecoder](query_recorder.md) to detect this and prevent regressions. In this particular case the workaround is fairly easy: @@ -117,6 +117,8 @@ Post.all.includes(:author).each do |post| end ``` +Also consider using [QueryRecoder tests](query_recorder.md) to prevent a regression when eager loading. + ## Memory Usage **Summary:** merge requests **must not** increase memory usage unless absolutely |