From: | Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> |
---|---|
To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
Cc: | Merlin Moncure <mmoncure(at)gmail(dot)com>, PostgreSQL Hackers <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: proposal: support empty string as separator for string_to_array |
Date: | 2009-07-27 17:59:56 |
Message-ID: | 162867790907271059u71a7cef8xb20376599d3fa2a0@mail.gmail.com |
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2009/7/27 Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>:
> Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> writes:
>> I tested implementation and it's about 30% faster than using regexp.
>
> In a real application, that's going to be negligible compared to all the
> other costs involved in pushing the data around. And we still haven't
> seen any in-the-field requests for this functionality, so even if the
> gap were wider, I don't see the point of putting effort into it.
>
This is just possible optimalisation - Maybe Merlin proposal is the
best - we could add this technique to regexp_split_to_array - when is
pattern empty, then we could to use direct char separation - without
any new function or change of current function. And somebody, that use
regexp_split_to_array now will have profit too.
Pavel
> regards, tom lane
>
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