Re: update inside function does not use the index - Mailing list pgsql-general

From Johannes
Subject Re: update inside function does not use the index
Date
Msg-id 564A3A4D.8020504@posteo.de
Whole thread Raw
In response to Re: update inside function does not use the index  (Adrian Klaver <adrian.klaver@aklaver.com>)
List pgsql-general
No, i did a mistake while simplifying it.

It should be

FOR i IN SELECT id, level, path_names||'%' as path_names from x LOOP
update x set path_ids[i.level] = i.id where path_names like i.path_names;

Sorry.
Best regards Johannes

Am 16.11.2015 um 15:10 schrieb Adrian Klaver:
> On 11/16/2015 05:56 AM, Johannes wrote:
>> Dear List,
>>
>> I have problems with a self written function, which does not use the
>> index, which takes very long (500 ms per update).
>>
>>
>> The pl/pgsql function iterates over a select resultset with a cursor.
>> In every loop I execute an update with a where LIKE condition, which
>> relates to my current cursor position:
>>
>> FOR i IN SELECT id, level_ids, path_names||'%' as path_names from x LOOP
>> update x set path_ids[i.level] = id where path_names like i.path_names;
>
> Is this the actual UPDATE in the function?
>
> If so, where are i.level and id  coming from?
>
> Or is that supposed to be?:
>
> update x set path_ids[i.level_ids] = i.id where path_names like
> i.path_names;
>
>> RAISE NOTICE 'path_names : %', i.path_names;
>> END LOOP;
>>
>>
>>
>> Calling the updates outside the function, they are very fast because
>> like 'a.b%' uses the index of the path field ( ~ 15 ms ).
>>
>> Does anyone know how to fix that?
>> Thanks, Johannes
>>
>
>


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