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Re: update inside function does not use the index

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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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Adrian Klaver
adrian.klaver@xxxxxxxxxxx


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