Merge branch 'performance-mass-insert' into 'master'

Performance development docs: Link to mass insert

See merge request gitlab-org/gitlab!27083

doc/development/performance.md

@@ -448,9 +448,12 @@ SOME_CONSTANT = 'bar'
 
 You might want millions of project rows in your local database, for example,
 in order to compare relative query performance, or to reproduce a bug. You could
-do this by hand with SQL commands, but since you have ActiveRecord models, you
-might find using these gems more convenient:
+do this by hand with SQL commands or using [Mass Inserting Rails
+Models](mass_insert.md) functionality.
 
+Assuming you are working with ActiveRecord models, you might also find these links helpful:
+
+- [Insert records in batches](insert_into_tables_in_batches.md)
 - [BulkInsert gem](https://github.com/jamis/bulk_insert)
 - [ActiveRecord::PgGenerateSeries gem](https://github.com/ryu39/active_record-pg_generate_series)