gitlab-org--gitlab-foss

Commit Graph

Author	SHA1	Message	Date
Jan Provaznik	0fc9f9d3e7	Add version 4.2 to all existing migrations DB schema generated by a migration may look different in rails 4 and 5 (because rails 5 may use different default values). For this reason it's important to explicitly set for which rails version a migration was written for. See https://stackoverflow.com/questions/35929869/activerecordmigration-deprecation-warning-asks-for-rails-version-but-im-no/35930912#35930912	2018-11-22 13:18:28 +01:00
Yorick Peterse	709dd23760	Added partial index for merge requests This index is added on `(target_project_id, iid)` and has a `WHERE state = 'opened'` condition. Using this index we can drastically improve the performance of the query used to count the total number of merge requests in a group. Without this index the query would eventually perform the following: -> Index Scan using index_merge_requests_on_target_project_id_and_iid on merge_requests (cost=0.43..4.89 rows=7 width=4) (actual time=0.058..0.353 rows=6 loops=228) Index Cond: (target_project_id = projects.id) Filter: ((state)::text = 'opened'::text) Rows Removed by Filter: 141 Buffers: shared hit=34351 dirtied=1 Out of the ~180 milliseconds the entire query would take, around 170 milliseconds was spent in just this segment. With the index in place, the above segment is turned into the following: -> Index Only Scan using yorick_test on merge_requests (cost=0.42..0.55 rows=7 width=4) (actual time=0.004..0.010 rows=6 loops=228) Index Cond: (target_project_id = projects.id) Heap Fetches: 419 Buffers: shared hit=1381 The index also reduces the total query time to roughly 10 milliseconds.	2018-05-28 13:52:41 +02:00

Author

SHA1

Message

Date

Jan Provaznik

0fc9f9d3e7

Add version 4.2 to all existing migrations

DB schema generated by a migration may look different in
rails 4 and 5 (because rails 5 may use different default values).
For this reason it's important to explicitly set for which rails
version a migration was written for.

See https://stackoverflow.com/questions/35929869/activerecordmigration-deprecation-warning-asks-for-rails-version-but-im-no/35930912#35930912

2018-11-22 13:18:28 +01:00

Yorick Peterse

709dd23760

Added partial index for merge requests

This index is added on `(target_project_id, iid)` and has a `WHERE state
= 'opened'` condition. Using this index we can drastically improve the
performance of the query used to count the total number of merge
requests in a group. Without this index the query would eventually
perform the following:

    ->  Index Scan using index_merge_requests_on_target_project_id_and_iid on merge_requests  (cost=0.43..4.89 rows=7 width=4) (actual time=0.058..0.353 rows=6 loops=228)
          Index Cond: (target_project_id = projects.id)
          Filter: ((state)::text = 'opened'::text)
          Rows Removed by Filter: 141
          Buffers: shared hit=34351 dirtied=1

Out of the ~180 milliseconds the entire query would take, around 170
milliseconds was spent in just this segment. With the index in place,
the above segment is turned into the following:

    ->  Index Only Scan using yorick_test on merge_requests  (cost=0.42..0.55 rows=7 width=4) (actual time=0.004..0.010 rows=6 loops=228)
          Index Cond: (target_project_id = projects.id)
          Heap Fetches: 419
          Buffers: shared hit=1381

The index also reduces the total query time to roughly 10 milliseconds.

2018-05-28 13:52:41 +02:00

2 Commits