Обсуждение: functions and plans

I am trying to figure out some issues with my functions and I was hoping
someone could help me.
My understanding is that the plan is made when the function is run the
first time. That means that running analyze on a table after a function
is run once won't change the plan.

I have a table that I populate, select and delete the data each time the
function is run. Each time I run the function it takes longer to get the
data. In these tests, the data is the exact same every time.

I tried putting vacuum inside the function, but I got an error, cannot
run vacuum inside of function.

Any thoughts?

Sim Zacks <sim@compulab.co.il> writes:
> I have a table that I populate, select and delete the data each time the
> function is run. Each time I run the function it takes longer to get the
> data. In these tests, the data is the exact same every time.

> I tried putting vacuum inside the function, but I got an error, cannot
> run vacuum inside of function.

TRUNCATE, maybe?

            regards, tom lane

Truncate won't work for me because I don't completely empty the table, I
just empty it for that user.
Each user has the table populated with his data, basically to work like
a temporary table. When the user runs a function it repopulates his
working table and then until he runs the function again he has that
dataset to work with. (I just noticed I wrote select and delete,
actually it deletes and then selects)


Tom Lane wrote:
> Sim Zacks <sim@compulab.co.il> writes:
>> I have a table that I populate, select and delete the data each time the
>> function is run. Each time I run the function it takes longer to get the
>> data. In these tests, the data is the exact same every time.
>
>> I tried putting vacuum inside the function, but I got an error, cannot
>> run vacuum inside of function.
>
> TRUNCATE, maybe?
>
>             regards, tom lane
>
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On Tue, May 23, 2006 at 04:19:56PM +0200, Sim Zacks wrote:
> I am trying to figure out some issues with my functions and I was hoping
> someone could help me.
> My understanding is that the plan is made when the function is run the
> first time. That means that running analyze on a table after a function
> is run once won't change the plan.
>
> I have a table that I populate, select and delete the data each time the
> function is run. Each time I run the function it takes longer to get the
> data. In these tests, the data is the exact same every time.
>
> I tried putting vacuum inside the function, but I got an error, cannot
> run vacuum inside of function.
>
> Any thoughts?

Best bet would probably be to turn on autovacuum. Short of that, setup a
cronjob.
--
Jim C. Nasby, Sr. Engineering Consultant      jnasby@pervasive.com
Pervasive Software      http://pervasive.com    work: 512-231-6117
vcard: http://jim.nasby.net/pervasive.vcf       cell: 512-569-9461