Re: [HACKERS] max backends checking patch

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: pgsql-hackers(at)postgreSQL(dot)org
Subject: Re: [HACKERS] max backends checking patch
Date: 1999-01-10 17:07:54
Message-ID: 9309.915988074@sss.pgh.pa.us
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Tatsuo Ishii <t-ishii(at)sra(dot)co(dot)jp> writes:
>> Couldn't postmaster just keep # of backends running
>> in some variable, instead of examining BackendList ?

> Yes, you could do that way. I just want to keep things simple.
> Seems a seed of "maintenance problem" in the future IMHO:-)

I agree with Tatsuo. Counting the children once per backend startup
is certainly not a performance bottleneck, so there is no reason to
add complexity and a source of potential bugs to speed it up.

> Having a counter inside the dllist module is another idea. If there
> were many codes in the backend that counting elemnts in the dllist,
> this would be worth to think about.

That would be reasonable if justified by usage --- the tradeoff is
the added cost of maintaining the count for every dllist, whether or
not it's ever asked for...

regards, tom lane

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