Sqlite on Cesar Gimenes

An encrypted vault in Go

crg@crg.eti.br (Cesar Gimenes) — Sun, 31 May 2026 01:02:01 -0300

Let’s put together the three previous pieces:

A SQLite database that lives in RAM and, on disk, exists only as an encrypted blob.

The database runs in :memory:. On exit, we take a snapshot of the database bytes, encrypt it with the password, and write it out. On startup, we read the blob, decrypt it with the password, and deserialize it back into RAM.

SQLite in RAM: serialize and deserialize in Go

crg@crg.eti.br (Cesar Gimenes) — Sun, 31 May 2026 00:46:31 -0300

SQLite can run entirely in memory, without ever touching disk. And there is a little-known trick: you can take a snapshot of the database bytes and load them back later, with no INSERT, no rebuilding anything. The functions are sqlite3_serialize and sqlite3_deserialize.

I will use the modernc.org/sqlite driver, which is pure Go, no CGo.

db, err := sql.Open("sqlite", ":memory:")
if err != nil {
 fatal(err)
}
db.SetMaxOpenConns(1)

The catch is in SetMaxOpenConns(1). A :memory: database belongs to the connection that opened it. Without limiting it to one connection, the database/sql pool could open another one, and that one would see a different, empty database.

Triggers in SQLite

crg@crg.eti.br (Cesar Gimenes) — Fri, 03 Oct 2025 23:57:24 -0300

SQLite does not support stored procedures directly, but it does support triggers, which is a very useful feature for automating certain actions.

For example, automatically updating the updated_at field.

CREATE TABLE users (
 id INTEGER PRIMARY KEY AUTOINCREMENT,
 nome TEXT,
 updated_at DATETIME DEFAULT CURRENT_TIMESTAMP
);

CREATE TRIGGER update_timestamp
BEFORE UPDATE ON users
FOR EACH ROW
BEGIN
 UPDATE users SET updated_at = CURRENT_TIMESTAMP WHERE id = OLD.id;
END;

Now, whenever you update a record in the users table, the updated_at field will be automatically set to the current timestamp.