Frequent queries pollute pg_stat_statements

[steve-chavez]

Problem

Currently we run two queries every second (ref1, ref2, ref3), note that one does a DELETE to avoid having the http_request_queue from growing too much. This pollutes pg_stat_statements and causes some users to complain and wrongly think that pg_net is causing a lot of iops.

Solution

We can instead add the requests done with net.http_get and others to an in-memory queue, and then read from this queue whenever there are entries available.

This can be done without a breaking change by adding a trigger to the net.http_request_queue table.

Related

Solving this issue can be a stepping stone towards #62.