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.
--
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?
Patrick
>The OP wants to run queries on the master and the slave, and combine them.
Another option, although a bit convoluted, would be to extract the data to a csv file, scp it to destination server, and then copy in from there
eg: Contents of bash script =================== #!/bin/bash
psql -U postgres
\t
\f c
\o results.csv select now() as time_pk, client_addr, state, sent_location, write_location, flush_location, replay_location, sync_priority from pg_stat_replication;
\q
scp results.csv destination_server/tmp/.
psql -U postgres -h destination_server/tmp/.
COPY data_table FROM '\tmp\results.csv' WITH csv;
\q
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I see...
but there is queries like this:
select now() - pg_last_xact_replay_timestamp() AS replication_delay;
that need to be ran into a slave.. how can I insert that data into a table on the slave?
