Skip to content

Enhance performance of counting local LFS objects

Toon Claes requested to merge tc-index-lfs-objects-file-store into master

What does this MR do?

Add an index to the file_store column on lfs_objects. This makes counting local objects faster.

Also, there is no longer need to check for objects with file_store being NULL. See https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/18557

Query plans

Before & with NULL 

Aggregate  (cost=113495.96..113495.97 rows=1 width=8) (actual time=1691.394..1691.394 rows=1 loops=1)
  ->  Seq Scan on lfs_objects  (cost=0.00..106415.50 rows=2832186 width=0) (actual time=0.012..1312.488 rows=2852607 loops=1)
        Filter: ((file_store = 1) OR (file_store IS NULL))
        Rows Removed by Filter: 131
Planning time: 0.077 ms
Execution time: 1691.433 ms

Before, without NULL 

Aggregate  (cost=113495.96..113495.97 rows=1 width=8) (actual time=856.423..856.424 rows=1 loops=1)
  ->  Seq Scan on lfs_objects  (cost=0.00..106415.50 rows=2832186 width=0) (actual time=0.012..672.181 rows=2852607 loops=1)
        Filter: (file_store = 1)
        Rows Removed by Filter: 131
Planning time: 0.128 ms
Execution time: 856.470 ms

After & with NULL 

Aggregate  (cost=68819.95..68819.96 rows=1 width=8) (actual time=583.355..583.355 rows=1 loops=1)
  ->  Index Only Scan using index_lfs_objects_on_file_store on lfs_objects  (cost=0.43..61688.35 rows=2852643 width=0) (actual time=0.028..399.177 rows=2852607 loops=1)
        Filter: ((file_store = 1) OR (file_store IS NULL))
        Rows Removed by Filter: 131
        Heap Fetches: 867
Planning time: 0.096 ms
Execution time: 583.404 ms

After, without NULL 

Aggregate  (cost=68817.29..68817.30 rows=1 width=8) (actual time=490.550..490.551 rows=1 loops=1)
  ->  Index Only Scan using index_lfs_objects_on_file_store on lfs_objects  (cost=0.43..61685.68 rows=2852643 width=0) (actual time=0.040..311.760 rows=2852607 loops=1)
        Index Cond: (file_store = 1)
        Heap Fetches: 831
Planning time: 0.294 ms
Execution time: 490.590 ms

What are the relevant issue numbers?

Closes https://gitlab.com/gitlab-org/gitlab-ee/issues/6067

Does this MR meet the acceptance criteria?

Edited by Toon Claes

Merge request reports