Date: Mon, 15 Jan 2018 22:02:57 +0300
From: Arthur Zakirov <a.zakirov@postgrespro.ru>
To: Tomas Vondra <tomas.vondra@2ndquadrant.com>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Subject: Re: [PROPOSAL] Shared Ispell dictionaries
Message-ID: <20180115190104.GA2622@arthur.localdomain>
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On Sat, Jan 13, 2018 at 10:33:14PM +0100, Tomas Vondra wrote:
> Not sure if we really need to add the database/schema OIDs. I mentioned
> the unexpected consequences (cross-db sharing) but maybe that's a
> feature we should keep (it reduces memory usage). So perhaps this should
> be another CREATE TEXT SEARCH DICTIONARY parameter, allowing sharing the
> dictionary with other databases?
> 
> Aren't we overengineering this?

Another related problem I've noticed is memory leak. When a dictionary
loaded and then dropped it won't be unloaded. I see several approaches:

1 - Use Oid of the dictionary itself as the key instead dictfile and
afffile. When the dictionary is dropped it will be easily unloaded if it
was loaded. Implementing should be easy, but the drawback is more memory consumption.
2 - Use reference counter with cross-db sharing. When the dictionary is
loaded the counter increases. If all record of loaded dictionary is dropped
it will be unloaded.
3 - Or reference counters without cross-db sharing to avoid possible confusing.
Here dictfile, afffile and database Oid will be used as the key.

-- 
Arthur Zakirov
Postgres Professional: http://www.postgrespro.com
Russian Postgres Company