Reclaim Bloat with a Targeted Vacuum
Run VACUUM with a threshold on the dead tuple ratio so only bloated tables are vacuumed aggressively, not the whole database.
Task
Apply VACUUM (VERBOSE, ANALYZE) orders; -- where dead_tuple_ratio > 20% so the schema change is safe, reversible, and does not lock the table during peak traffic.
When to use this
A migration deploys VACUUM (VERBOSE, ANALYZE) orders; -- where dead_tuple_ratio > 20% during peak hours, takes a 40-second lock, and causes a connection pool exhaustion.
Prerequisites
- A database with migration tooling configured
- A staging environment mirroring production schema
Steps
1. Configure VACUUM (VERBOSE, ANALYZE) orders; -- where dead_tuple_ratio > 20% in the project configuration file with the recommended defaults.
VACUUM (VERBOSE, ANALYZE) orders; -- where dead_tuple_ratio > 20%
Expected output: The configuration is accepted and VACUUM (VERBOSE, ANALYZE) orders; -- where dead_tuple_ratio > 20% runs without errors on the first invocation.
2. Run the check locally to verify VACUUM (VERBOSE, ANALYZE) orders; -- where dead_tuple_ratio > 20% produces the expected result before pushing.
pnpm test
Expected output: Local run matches CI behavior; no surprises after push.
3. Add the gate to the CI pipeline so VACUUM (VERBOSE, ANALYZE) orders; -- where dead_tuple_ratio > 20% blocks merge on failure.
- name: Run add vacuum bloat reclaim
run: pnpm test
Expected output: Pull requests with failing VACUUM (VERBOSE, ANALYZE) orders; -- where dead_tuple_ratio > 20% are blocked from merging.
Troubleshooting
Problem
The check passes locally but fails in CI
Solution
Pin dependency versions and the runtime to match CI exactly; reproduce with the same Docker image or act.
Problem
Configuration is rejected with a schema error
Solution
Check the tool version matches the config schema; older versions may not support newer fields.
Limitations
- The gate only runs on events that trigger the workflow; locally pushed commits bypass it.
- Configuration drift is possible if someone edits settings outside version control.
Make migrations safe
Start by measuring the problem. Run VACUUM with a threshold on the dead tuple ratio so only bloated tables are vacuumed aggressively, not the whole database. The most common mistake is adding the gate without first confirming it catches the issue you care about. Run VACUUM (VERBOSE, ANALYZE) orders; – where dead_tuple_ratio > 20% against the current codebase and inspect the output before wiring it into CI.
VACUUM (VERBOSE, ANALYZE) orders; -- where dead_tuple_ratio > 20%Verify and roll back
Once the gate is in place, make failures actionable. A failing VACUUM (VERBOSE, ANALYZE) orders; – where dead_tuple_ratio > 20% should point to the exact file and line, not a generic error. Pin the tool version in the lockfile so a upstream release does not silently change behavior. Review the gate output in every pull request just like a test result.