paulononato/backstage
1
0
Fork 0
Code Issues Pull Requests Actions 48 Packages Projects Releases Wiki Activity

catalog-backend: add missing index on relations.target_entity_ref

Browse Source 
The relations table had indexes on originating_entity_id and
source_entity_ref but none on target_entity_ref. Several query paths
join or filter on this column:

- Orphan deletion (LEFT JOIN relations ON target_entity_ref)
- Entity ancestry (INNER JOIN relations ON target_entity_ref)
- Eager pruning (JOIN relations ON target_entity_ref)

Without an index these queries seq-scan the full table (~3.5M rows,
714 MB heap). On a production replica, a single point lookup takes
~122ms via seq scan. With the index it drops to <1ms.

The index is ~141 MB based on column width (~35 bytes avg) across
~3.5M rows. On PostgreSQL it's created with CONCURRENTLY to avoid
blocking reads/writes.

Signed-off-by: Fredrik Adelöw <freben@gmail.com>

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Signed-off-by: Fredrik Adelöw <freben@gmail.com>
This commit is contained in:
Fredrik Adelöw
2026-05-16 19:38:40 +02:00
parent a29edc58fb
commit bc32c13de6
4 changed files with 169 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files
.changeset/relations-target-index.md
+5
View File
@@ -0,0 +1,5 @@
---
'@backstage/plugin-catalog-backend': patch
---
Added a missing index on `relations.target_entity_ref`. Several query paths (orphan deletion, entity ancestry, eager pruning) join or filter on this column, but no index existed — causing full sequential scans of the relations table on every invocation. On a production catalog with ~3.5M relation rows, individual lookups were taking ~122ms (full table scan) instead of <1ms (index scan).