fix(postgres): create content trigram index with fastupdate=off#606
Open
flexiondotorg wants to merge 2 commits into
Open
fix(postgres): create content trigram index with fastupdate=off#606flexiondotorg wants to merge 2 commits into
flexiondotorg wants to merge 2 commits into
Conversation
idx_messages_content_trgm is created with PostgreSQL's default fastupdate=on. The resulting GIN pending list is only merged into the index by VACUUM, so under continuous `pg sync` ingest where long-lived transactions pin the xmin horizon and starve autovacuum, it grows without bound. In one deployment the index bloated to 283 GB for ~213k rows and filled the disk, crashing PostgreSQL with ENOSPC. Disabling fastupdate merges entries directly into the tree, keeping the index bounded and predictable at a small per-insert cost.
roborev: Combined Review (
|
CREATE INDEX IF NOT EXISTS only applies WITH (fastupdate = off) on first creation, so stores upgraded from an earlier schema retained the default fastupdate=on. Reapply idempotently with ALTER INDEX on every schema bootstrap, and assert reloptions in the pgtest suite. Addresses review feedback on kenn-io#606.
roborev: Combined Review (
|
Collaborator
|
So whats the performance impact of this change? Since the alternate would be something like running |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Closes #605.
Adds
WITH (fastupdate = off)to theidx_messages_content_trgmcreation increateContentSearchIndexesPG, and reapplies it idempotently viaALTER INDEXon every schema bootstrap so stores upgraded from a schema that created the index with the defaultfastupdate=onare covered too. A pgtest assertion guardsreloptions. See #605 for the diagnosis and impact.Validation: recreating the index with
fastupdate=offreduced the same data from 283 GB to 388 MB.Existing over-sized indexes stop growing immediately; a one-time
REINDEXreclaims space already consumed.