Forum OpenACS Development: Re: Disconnected PG clients hose the server

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Posted by Dan Lieberman on
Lamar,
As a rule an SQL query on an ADP page should deliver the goods very quickly. We have a browser-based report writer application that incorporates a wizard that generates an SQL query - so there ARE cases where a user may wait for a minute or so to get the results when the query is very complicated and there is a fair volume of data to write to the browser. Unfortunately - you can tell a user not to hit stop and they will get pissed off and still hit stop and sometimes even hit stop and refresh several times!

I am tempted to redesign the report writer to run in a ns_schedule process and return the results in HTML by email.  This would probably make the problem go away.

Having said that - there is a curious problem with PG. When the user disconnects by STOP or closing the browser - the PG process running the SELECT NEVER finishes.
Thats why i called it a zombie (even tho' thats an incorrect definion by unix terms) - I would have thought that the process WOULD complete the SELECT and drop its results into the bit bucket.

This is whats really troubling me. It smells like a bug in the AOLServer PG driver
Danny