Re: select count() out of memory

From: tfinneid(at)student(dot)matnat(dot)uio(dot)no
To: "Alvaro Herrera" <alvherre(at)commandprompt(dot)com>
Cc: tfinneid(at)student(dot)matnat(dot)uio(dot)no, "Gregory Stark" <stark(at)enterprisedb(dot)com>, pgsql-general(at)postgresql(dot)org
Subject: Re: select count() out of memory
Date: 2007-10-25 12:28:04
Message-ID: 42923.134.32.140.234.1193315284.squirrel@webmail.uio.no
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

> tfinneid(at)student(dot)matnat(dot)uio(dot)no wrote:
>
>> > are a dump of Postgres's current memory allocations and could be
>> useful in
>> > showing if there's a memory leak causing this.
>>
>> The file is 20M, these are the last lines: (the first line continues
>> unttill ff_26000)
>>
>>
>> idx_attributes_g1_seq_1_ff_4_value7: 1024 total in 1 blocks; 392 free (0
>> chunks); 632 used
>
> You have 26000 partitions???

At the moment the db has 55000 partitions, and thats only a fifth of the
complete volume the system will have in production. The reason I chose
this solution is that a partition will be loaded with new data every 3-30
seconds, and all that will be read by up to 15 readers every time new data
is available. The data will be approx 2-4TB in production in total. So it
will be too slow if I put it in a single table with permanent indexes.

I did a test previously, where I created 1 million partitions (without
data) and I checked the limits of pg, so I think it should be ok.

thomas

In response to

Responses

Browse pgsql-general by date

  From Date Subject
Next Message Alvaro Herrera 2007-10-25 12:41:04 Re: select count() out of memory
Previous Message Evandro Andersen 2007-10-25 12:25:14 Delete/Update with ORDER BY