In postgresql environments, it is common for tables and indexes to gradually grow in size due to frequent UPDATE and DELETE operations. Over time, this leads to table and index bloat, increased storage consumption, and slower query performance.
Traditionally, the standard approach to reclaiming space has been VACUUM FULL. While effective in reducing bloat, it comes with a major operational challenge — it requires an exclusive lock on the table. During execution, both reads and writes are blocked, which results in downtime. In production systems, especially high-availability environments, this is often not acceptable.
To solve this challenge, we adopted pg_repack, a PostgreSQL extension designed to reclaim space and reorganize tables without significant downtime.
Unlike VACUUM FULL, pg_repack works by creating a live copy of the table, tracking ongoing changes through triggers, and then seamlessly swapping the new optimized table with the original. This allows normal database activity to continue while the reorganization is in progress.
In our environment, pg_repack was introduced as part of routine database maintenance to manage storage growth and improve efficiency. A scheduled execution was implemented to ensure consistent cleanup of table and index bloat, reducing the need for manual intervention and avoiding the performance disruption associated with full table locks.
Beyond improving storage utilization, this approach has helped maintain stable performance for critical workloads while ensuring maintenance activities remain transparent to application users.
Although pg_repack is an online operation, it is still resource-intensive. For this reason, it is executed during off-peak periods to minimize any impact on production workloads.
