Show HN: Embed an SQLite database in your PostgreSQL table

pglite-fusion is a PostgreSQL extension that allows you to embed SQLite databases into your PostgreSQL tables by enabling the creation of columns with the `SQLITE` type. This means every row in the table can have an embedded SQLite database.

In addition to the PostgreSQL `SQLITE` type, pglite-fusion provides the `query_sqlite`` function for querying SQLite databases and the `execute_sqlite` function for updating them. Additional functions are listed in the project’s README.

The pglite-fusion extension is written in Rust using the pgrx framework [1].

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Implementation Details

The PostgreSQL `SQLITE` type is stored as a CBOR-encoded `Vec<u8>`. When a query is made, this `Vec<u8>` is written to a random file in the `/tmp` directory. SQLite then loads the file, performs the query, and returns the result as a table containing a single row with an array of JSON-encoded values.

The `execute_sqlite` function follows a similar process. However, instead of returning query results, it returns the contents of the SQLite file (stored in `/tmp`) as a new `SQLITE` instance.

[1] https://github.com/pgcentralfoundation/pgrx