index “…” contains unexpected zero page

SQLSTATE XX002 condition index_corrupted class XX — Internal Error severity ERROR

Reproduced & verified on PostgreSQL 14.23, 15.18, 16.14, 17.10 and 18.4 — identical message on every version.

Last reviewed 11 Jun 2026 · Reproduced live with the SQL on this page.

Symptoms

An index access found an unexpected zero (all-zero) page, indicating index corruption. PostgreSQL raises SQLSTATE XX002 (index_corrupted).

An index page is unexpectedly all zeros.
Index scans on the relation may fail.
Often a crash- or storage-related fault.

What the server log shows

ERROR:  index "orders_pkey" contains unexpected zero page at block 99

Why PostgreSQL raises this — what the manual says

As the REINDEX reference (Description) explains:

The index’s on-disk structure is inconsistent with the underlying table — commonly caused by storage faults, collation-library changes, or an unclean shutdown; REINDEX rebuilds the index from scratch to restore a valid structure.

Index pages must be properly initialized. Encountering an all-zero page where data is expected means the index structure is damaged, so PostgreSQL reports XX002. Because indexes are derived data, they can usually be rebuilt.

Common causes

A crash during index writes (especially with fsync off).
Storage/hardware faults zeroing pages.
A bad restore or filesystem corruption.

How to fix it

Rebuild the index: REINDEX INDEX CONCURRENTLY orders_pkey;.
Use amcheck to scan for other corrupt indexes.
Investigate the underlying storage; indexes corrupting repeatedly signal hardware issues.

Related & next steps

Reference: PostgreSQL 18 — REINDEX.