I have a postgres 9.0.5 database set up with several hot standbys.

From the hot standbys i execute an sql statement (SELECT 1) every second to verify that the database is still available.

On the primary database, I run a pretty large update every hour, in which i delete and insert several rows(delete, insert, delete, insert, etc...).

occasionally the hot standbys(all of them) will kill the session executing the SELECT 1 statement during the time that i am running the large update.

Is there a reason why postgres would kill this query which is not accessing any tables in the database? It doesn't happen every hour, or on any specific schedule...it appears to be completely random.

any help is greatly appreciated, and please let me know if there are any database parameters i should post in here to better help understand/diagnose my issue.

Thank you.