Locked due to shared-cache contention

Category: LockingVersions: 3.0+

🔴 Production Risk Error

Medium — causes contention; migrate away from shared-cache.

What this means

SQLITE_LOCKED_SHAREDCACHE (262) is an extended result code returned in shared-cache mode when one connection attempts to access a table that another connection in the same shared cache has locked.

Why it happens

1Shared-cache mode enabled (SQLITE_ENABLE_SHARED_CACHE) with concurrent connections reading/writing the same table.
2Two connections sharing the same page cache holding conflicting table-level locks.

How to reproduce

Shared-cache mode (deprecated since SQLite 3.36.0).

trigger — this will ERROR

-- Enable shared cache (deprecated):
PRAGMA cache = shared;
-- Concurrent connection locking same table triggers SQLITE_LOCKED_SHAREDCACHE

sqlite3.OperationalError: database table is locked

Fix 1

Why this works

Avoid shared-cache mode — it is deprecated since SQLite 3.36.0.

Fix 2

Why this works

Use WAL mode with separate caches for better concurrent read performance.

What not to do

✗

Why it's wrong:

Version notes

Sources

📚 Official docs: https://www.sqlite.org/rescode.html#locked_sharedcache

🔧 Source ref: sqlite3.h — SQLITE_LOCKED_SHAREDCACHE = 262

📖 Further reading: Shared cache mode

Confidence assessment

⚠️ MEDIUM confidence

Stable.