Re: update inside function does not use the index

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
>


-- 
Adrian Klaver
adrian.klaver@aklaver.com