Postgres pgx plugin
This module implements a Postgres implementation of the micro store interface.
It uses modern https://github.com/jackc/pgx driver to access Postgres.
Implementation notes
Concepts
Every database has they own connection pool. Due to the way connections are handled this means that all micro "databases" and "tables" can be stored under a single or several Postgres database as specified in the connection string (https://www.postgresql.org/docs/8.1/ddl-schemas.html). The mapping of micro to Postgres concepts is:
- micro database => Postgres schema
- micro table => Postgres table
Expiry
Expiry is managed by an expiry column in the table. A record's expiry is specified in the column and when a record is read the expiry field is first checked, only returning the record if it's still valid otherwise it's deleted. A maintenance loop also periodically runs to delete any rows that have expired.