Re: Memory leak in vac_update_relstats ?

From: NikhilS <nikkhils(at)gmail(dot)com>
To: "Heikki Linnakangas" <heikki(at)enterprisedb(dot)com>
Cc: "Pavan Deolasee" <pavan(dot)deolasee(at)gmail(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Memory leak in vac_update_relstats ?
Date: 2007-07-20 12:47:22
Message-ID: d3c4af540707200547w7d972cb5v3155932212bf6be2@mail.gmail.com
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Hi,

That's the beauty of memory contexts for small allocations. But because of
> the 'convenience' of memory contexts we sometimes tend to not pay attention
> to doing explicit pfrees. As a general rule I think allocations in
> TopMemoryContext should be critically examined. I was bitten by this undue
> bloat recently while developing some code and valgrind is not of much help
> in such cases because of this very beauty of memory contexts :).

One specific case I want to mention here is hash_create(). For local hash
tables if HASH_CONTEXT is not specified, they get created in a context which
becomes a direct child of TopMemoryContext. Wouldn't it be a better idea to
create the table in CurrentMemoryContext?

If hash_destroy() is not explicitly invoked, this can cause a lot of bloat
especially if the intention was to use the hash table only for a while.

Regards,
Nikhils

Regards,
Nikhils

--
EnterpriseDB http://www.enterprisedb.com

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