Serializing Sqlite3 in Python

Question

To fully utilize concurrency, SQLite3 allows threads to access the same connection in three ways:

1. Single-thread. In this mode, all mutexes are disabled and SQLite is unsafe to use in more than a single thread at once.
2. Multi-thread. In this mode, SQLite can be safely used by multiple threads provided that no single database connection is used simultaneously in two or more threads.
3. Serialized. In serialized mode, SQLite can be safely used by multiple threads with no restriction.

Does anyone know how I can make the connection serialized in Python.
Python has "check_same_thread" which allows switching between multi-threading and single-threading; however, I can not find out how I should make it serialized.

Answer 1

The Python SQLite module is not threadsafe. If you disable its checking then you need to ensure all code is serialized and that includes garbage collection. (My APSW module is threadsafe and also correctly handles the error message thread safety issues).

It is however safe to use multiple independent connections concurrently in the same process and I would recommend you do that. Additionally switch the database into write ahead logging mode and you should get very good performance even with lots of writing.