Subject: Re: [PROPOSAL] Shared Ispell dictionaries
To: Tomas Vondra <tomas.vondra@2ndquadrant.com>,
 Robert Haas <robertmhaas@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Pavel Stehule <pavel.stehule@gmail.com>,
 Andres Freund <andres@anarazel.de>,
 pgsql-hackers <pgsql-hackers@postgresql.org>
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From: Arthur Zakirov <a.zakirov@postgrespro.ru>
Message-ID: <337f7a55-58b8-4fcc-a933-5e7799fa6882@postgrespro.ru>
Date: Wed, 16 Jan 2019 14:42:44 +0300
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Hello Tomas,

On 16.01.2019 03:23, Tomas Vondra wrote:
> I've looked at the patch today, and in general is seems quite solid to
> me. I do have a couple of minor points
> 
> 1) I think the comments need more work. Instead of describing all the
> individual changes here, I've outlined those improvements in attached
> patches (see the attached "tweaks" patches). Some of it is formatting,
> minor rewording or larger changes. Some comments are rather redundant
> (e.g. the one before calls to release the DSM segment).

Thank you!

> 2) It's not quite clear to me why we need DictInitData, which simply
> combines DictPointerData and list of options. It seems as if the only
> point is to pass a single parameter to the init function, but is it
> worth it? Why not to get rid of DictInitData entirely and pass two
> parameters instead?

In the first place init method had two parameters. But in the v7 patch I 
added DictInitData struct instead of two parameters (list of options and 
DictPointerData):
https://www.postgresql.org/message-id/20180319110648.GA32319%40zakirov.localdomain

I haven't way to replace template's init method from 
init_method(internal) to init_method(internal,internal) in the upgrade 
script of extensions. If I'm not mistaken we need new syntax here, like 
ALTER TEXT SEARCH TEMPLATE. Thoughts?

> 3) I find it a bit cumbersome that before each ts_dict_shmem_release
> call we construct a dummy DickPointerData value. Why not to pass
> individual parameters and construct the struct in the function?

Agree, it may look too verbose. I'll change it.

> 4) The reference to max_shared_dictionaries_size is obsolete, because
> there's no such limit anymore.

Yeah, I'll fix it.

 > /* XXX not really a pointer, so the name is misleading */

I think we don't need DictPointerData struct anymore, because only 
ts_dict_shmem_release function needs it (see comments above) and we only 
need it to hash search. I'll move all fields of DictPointerData to 
TsearchDictKey struct.

 > XXX "supported" is not the same as "all ispell dicts behave like that".

I'll reword the sentence.

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