You can try pg_cron. https://github.com/citusdata/pg_cron "pg_cron is a simple cron-based job scheduler for PostgreSQL (9.5 or higher) that runs inside the database as an extension. It uses the same syntax as regular cron, but it allows you to schedule PostgreSQL commands directly from the database"
Yep.. once a minute or so. And yes, I need to store a history with timestamp.
Any idea? :)
so create a table with a timestamptz, plus all the fields you want, have a script (perl? python? whatever your favorite poison is with database access) that once a minute executes those two queries (you'll need two database connections since only the slave knows how far behind it is), and inserts the data into your table.
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john r pierce, recycling bits in santa cruz
Can't I do it on the DB size? Using a trigger maybe? instead of using Cron?