Optimize channel_updates and node_announcements queries, drop unused indexes by TheBlueMatt · Pull Request #106 · lightningdevkit/rapid-gossip-sync-server

TheBlueMatt · 2026-03-03T14:00:57Z

Rewrite the "oldest bidirectional update" query to use two explicit
LATERAL joins (one per direction, each LIMIT 1) instead of DISTINCT ON
(direction), which scanned ~4000 rows per scid through the index.

Rewrite the node_announcements reference query and channel_updates
reference query to use LATERAL joins instead of DISTINCT ON / subquery
patterns, forcing efficient index usage instead of sequential scans.

Drop four unused/redundant indexes (schema 15 -> 17):
- channel_updates_scid_dir_seen_desc_with_id (unused, backward scan on _asc used instead)
- channel_updates_scid_asc_timestamp_desc (unused by any query)
- channel_updates_seen (redundant with channel_updates_seen_scid)
- node_announcements_seen_pubkey (unused, replaced by _pubkey_seen_desc)
- node_announcements_pubkey_timestamp_desc (unused by any query)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Speeds up queries pretty well. I'm sure to an SQL person these conversions are obvious but I of course don't know SQL.

…indexes Rewrite the "oldest bidirectional update" query to use two explicit LATERAL joins (one per direction, each LIMIT 1) instead of DISTINCT ON (direction), which scanned ~4000 rows per scid through the index. Rewrite the node_announcements reference query and channel_updates reference query to use LATERAL joins instead of DISTINCT ON / subquery patterns, forcing efficient index usage instead of sequential scans. Drop four unused/redundant indexes (schema 15 -> 17): - channel_updates_scid_dir_seen_desc_with_id (unused, backward scan on _asc used instead) - channel_updates_scid_asc_timestamp_desc (unused by any query) - channel_updates_seen (redundant with channel_updates_seen_scid) - node_announcements_seen_pubkey (unused, replaced by _pubkey_seen_desc) - node_announcements_pubkey_timestamp_desc (unused by any query) Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ldk-reviews-bot · 2026-03-03T14:00:59Z

I've assigned @jkczyz as a reviewer!
I'll wait for their review and will help manage the review process.
Once they submit their review, I'll check if a second reviewer would be helpful.

ldk-reviews-bot · 2026-03-05T14:12:04Z

🔔 1st Reminder