Re: ANALYZE locks pg_listener in EXCLUSIVE for long

At 07:33 PM 3/05/2004, Philip Warner wrote:
>I'll try not to send any more emails until someone responds ;-)

I also noticed this in SIInsertDataEntry sinvaladt.c:

/*
* Try to prevent table overflow. When the table is 70% full send a
* WAKEN_CHILDREN request to the postmaster. The postmaster will send
* a SIGUSR2 signal (ordinarily a NOTIFY signal) to all the backends.
* This will force idle backends to execute a transaction to look
* through pg_listener for NOTIFY messages, and as a byproduct of the
* transaction start they will read SI entries.
*
* This should never happen if all the backends are actively executing
* queries, but if a backend is sitting idle then it won't be starting
* transactions and so won't be reading SI entries.
*
* dz - 27 Jan 1998
*/

Would a long-running ANALYZE (or other activity on a busy database) cause
the shared buffers to get to the 70% threshold while doing a long-running
ANALYZE?

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