Re: Slow running to_tsvector (tsearch2 in PG 8.2.3)

21 feb 2007 kl. 15:44 skrev Tom Lane:

> Markus Schiltknecht <markus@bluegap.ch> writes:
>> Henrik Zagerholm wrote:
>>> Is this normal? What can I tweak in postgresql.conf to speed up big
>>> to_tsvector()?
>
>> Hm.. seems not too unreasonable to me.
>> Take a look at the stemmers or dictionaries involved. What do you
>> use there?
I tried both the default english and simple stemmers. Simple was a
little bit faster but not much.
>
What is your configuration ? to_tsvector does a lot of work.
I haven't tweaked the postgresql.conf yet. What should I focus on?
work_mem, shared_buffers?

> Also, I wonder how much of the time went into to_tsvector() and how
> much
> into updating the GIST or GIN index that I suppose is on the column.
> For a full update like this it might make sense to drop the index,
> update the column, rebuild the index from scratch.
I actually tested to remove the GIN index on the vectors column and
it didn't have any noticeable effect. Maybe because its the only
tuple in the database.

Thanks for all your input!

regards, henrik

>
>             regards, tom lane
>
> ---------------------------(end of
> broadcast)---------------------------
> TIP 5: don't forget to increase your free space map settings