Обсуждение: tsearch2 frequent updates

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tsearch2 frequent updates

От
Matthew Terenzio
Дата:

If I'm using Tsearch2 to search a public online forum, do you think
it's okay to update on every forum entry?

Put another way: is to_tsvector() resource intensive when used in this
way?


Re: tsearch2 frequent updates

От
Steve Atkins
Дата:
On Sat, Jul 23, 2005 at 02:37:42PM -0400, Matthew Terenzio wrote:

> If I'm using Tsearch2 to search a public online forum, do you think
> it's okay to update on every forum entry?
>
> Put another way: is to_tsvector() resource intensive when used in this
> way?

Depends on the update rate, I suspect. I found it far too slow for 5+
new messages a second back when it was new.

But you're probably handling less than that, and it's improved since
then.

You should probably benchmark a reaonable test case and see.

Cheers,
  Steve

Re: tsearch2 frequent updates

От
Oleg Bartunov
Дата:
On Sat, 23 Jul 2005, Steve Atkins wrote:

> On Sat, Jul 23, 2005 at 02:37:42PM -0400, Matthew Terenzio wrote:
>
>> If I'm using Tsearch2 to search a public online forum, do you think
>> it's okay to update on every forum entry?
>>
>> Put another way: is to_tsvector() resource intensive when used in this
>> way?
>
> Depends on the update rate, I suspect. I found it far too slow for 5+
> new messages a second back when it was new.
>
> But you're probably handling less than that, and it's improved since
> then.
>
> You should probably benchmark a reaonable test case and see.

in 8.1 performance should be certainly improved because we added
concurrency & recovery suppot  to GiST. Currently, whole table should be
exclusively locked for every update.

>
> Cheers,
>  Steve
>
> ---------------------------(end of broadcast)---------------------------
> TIP 9: In versions below 8.0, the planner will ignore your desire to
>       choose an index scan if your joining column's datatypes do not
>       match
>

     Regards,
         Oleg
_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83