pglite-tools

A selection of tools for working with PGlite databases, including pg_dump.

Install with:

1npm install @electric-sql/pglite-tools

pgDump

pg_dump is a tool for dumping a PGlite database to a SQL file, this is a WASM build of pg_dump that can be used in a browser or other JavaScript environments. You can read more about pg_dump in the Postgres docs.

Note: pg_dump will execute DEALLOCATE ALL; after each dump. Since this is running on the same (single) connection, any prepared statements that you have made before running pg_dump will be affected.

Options

• pg: A PGlite instance.
• args: An array of arguments to pass to pg_dump - see pg_dump docs for more details.
• fileName: The name of the file to write the dump to, defaults to dump.sql.

There are a number of arguments that are automatically added to the end of the command, these are:

• --inserts - use inserts format for the output, this ensures that the dump can be restored by simply passing the output to pg.exec().
• -j 1 - concurrency level, set to 1 as multithreading isn't supported.
• -f /tmp/out.sql - the output file is always written to /tmp/out.sql in the virtual file system.
• -U postgres - use the postgres user is hard coded.

Returns

• A File object containing the dump.

Caveats

• After restoring a dump, you might want to set the same search path as the initial db.

Example

1import { PGlite } from '@electric-sql/pglite'
2import { pgDump } from '@electric-sql/pglite-tools/pg_dump'
3
4const pg = await PGlite.create()
5
6// Create a table and insert some data
7await pg.exec(`
8  CREATE TABLE test (
9    id SERIAL PRIMARY KEY,
10    name TEXT
11  );
12`)
13await pg.exec(`
14  INSERT INTO test (name) VALUES ('test');
15`)
16
17// store the current search path so it can be used in the restored db
18const initialSearchPath = (await pg1.query<{ search_path: string }>('SHOW SEARCH_PATH;')).rows[0].search_path
19
20// Dump the database to a file
21const dump = await pgDump({ pg })
22// Get the dump text - used for restore
23const dumpContent = await dump.text()
24
25// Create a new database 
26const restoredPG = await PGlite.create()
27// ... and restore it using the dump
28await restoredPG.exec(dumpContent)
29
30// optional - after importing, set search path back to the initial one
31await restoredPG.exec(`SET search_path TO ${initialSearchPath};`);