Re: Cost limit.

On Fri, 18 May 2001, Bruce Momjian wrote:

> That is on the TODO list:
>
>         * Add SET or BEGIN timeout parameter to cancel query if waiting
>       too long

Actually I was thinking of something to cut the query off at the pass.  I
looked through the code, and it does a query plan and uses the one with
least cost.  So, theoretically, I should be able to hack the code so that
it will refuse to execute a query if the best query plan has an estimated
cost of over 100,000 for example.

Some kind of error like:  "Query not executed due to detection of possible
cross product."

Of course, I'd like to stay away from source hacks, besides It would be
nice to tune from postgresql.conf as a parameter like max_query_cost.

The source is a bit spaghetti-ish, and I'm having a hard time following
some of the macros, typedefs and structs.  I don't think I could add
a feature like this myself.

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| Shaun M. Thomas                INN Database Programmer              |
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