Re: string_to_array eats too much memory?

From: Michael Paesold <mpaesold(at)gmx(dot)at>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Tatsuo Ishii <ishii(at)sraoss(dot)co(dot)jp>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: string_to_array eats too much memory?
Date: 2006-11-09 08:26:33
Message-ID: 4552E639.9010606@gmx.at
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Tom Lane writes:
> Tatsuo Ishii <ishii(at)sraoss(dot)co(dot)jp> writes:
>> string_to_array() consumes too much memory. For example, to make
>> ~70k array elements, string_to_array seems to eat several Gig bytes
>> of memory.
>
> I'd argue that the problem comes from enlarging the work arrays only
> 64 elements at a time in accumArrayResult(). Most of the rest of the
> code deals with resizing arrays using a "double it each time it has
> to grow" approach, I wonder why this is different?

Without reading the code, I guess that simply means O(n^2) runtime. This
should be fixed, then, right?

Best Regards,
Michael Paesold

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