index_corrupted

What this means

PostgreSQL detected corruption in an index structure. Index pages or internal index pointers have failed consistency checks, making the index unreliable for query planning.

Why it happens

1. 1Storage hardware failure affecting index files
2. 2Power failure during index write operation without battery-backed write cache
3. 3Index file was modified outside of PostgreSQL (direct disk manipulation)
4. 4Bug in PostgreSQL or extension that wrote invalid data to an index page
5. 5RAM errors corrupting data before it was flushed to disk
6. 6Concurrent unsafe operations on the index

How to reproduce

Any query that reads through a corrupted index, or REINDEX/VACUUM detecting corruption

SELECT * FROM my_table WHERE id = 1;  -- if the index on id is corrupted

Fix 1: REINDEX the affected index

The underlying table data is intact and only the index is corrupted

REINDEX INDEX CONCURRENTLY my_table_id_idx;
-- Or rebuild all indexes on the table:
REINDEX TABLE CONCURRENTLY my_table;

Fix 2: Run pg_check or amcheck to verify index integrity

Investigating the scope of corruption

-- Using amcheck extension (PostgreSQL 10+):
CREATE EXTENSION IF NOT EXISTS amcheck;
SELECT bt_index_check('my_table_id_idx');

Fix 3: Restore from backup if table data is also corrupted

Both index and heap data are corrupted

-- Restore PostgreSQL data directory from a clean backup

What not to do

Version notes

Sources

Confidence assessment

See also