How do I back up a SQLite database? Does SQLite support the same SQL as PostgreSQL or MySQL? Is it hard to migrate from SQLite to PostgreSQL later? What is WAL mode, and should I enable it? Does SQLite work well for multi-user web applications?

There are actually multiple modes of SQLite operation but we're going to focus on Write-Ahead Logging(WAL). It's not the default mode so one needs to enable it by running PRAGMA journal_mode=WAL SQL statement.

How to Put WAL to the Test Yourself. Ready to stop theorizing and start seeing those numbers fly? Here’s a simple, three-step process to enable WAL mode, set your synchronization for maximum speed, and run your own a quick benchmark to prove its power.

Why SQLite WAL Mode Changes the Entire Game. Whenever I preach the gospel of embedded SQLite to frontend engineers, their eyes widen in panic: "Wait, Elena! Doesn’t SQLite lock the entire database file on every write?How WAL Mode Actually Works

How SQLite answers it. How do we commit durably without overwriting the live file? Write-ahead log. Append each changed page as a frame to a -wal file; the last frame of a commit carries a commit marker.

SQLite WAL mode decouples read operations from write operations entirely: background telemetry dispatchers reading batches for cloud transit never block concurrent sensor threads appending records to storage.

SQLite’s WAL mode provides more concurrency as readers do not block writers and writers do not block readers. Reading and writing can proceed concurrently. Traditional SQLite uses rollback journals.

If you run SQLite in WAL mode with a busy writer and a few readers, you may one day find a -wal file of several gigabytes next to a database that is much smaller. Autocheckpoint is on, nothing reports an error, and PRAGMA wal_checkpoint says it worked.

I had read about SQLite's WAL mode but never fully understood how it works.If you want to turn WAL mode off and go back to the SQLite default, the unintuitive way to do that is: PRAGMA journal_mode=delete; Using sqlite-utils.

WAL mode requires shared memory, so doesn’t work over the network. mmap_size = 1TiB requires 1TiB of address space per connection. This is fine on 64-bit, unless you have millions of connections. Doesn’t work with 32-bit (4GiB) address space.