Since it's my first on this list, I'd like to say Hi guys :)
Here is definition of my table:
a9-dev= \d records;
Table public.records
Column|Type | Modifiers
How many rows do you have in that table?
a9-dev= select count(*) from records;
count
-
3620311
(1 row)
a9-dev= select source_id, count(*) from records where source_id =
'http://ebuw.uw.edu.pl/dlibra/oai-pmh-repository.xml' or source_id =
Hello,
Thanks for your suggestions !
We CLUSTERED a table using mostly used Index. Application is performing
better now.
Thanks
VB
On Tue, Sep 27, 2011 at 6:01 PM, Venkat Balaji venkat.bal...@verse.inwrote:
Forgot to mention -
Kevin,
CLUSTER seems to be an very interesting concept to me.
2011/10/3 Nowak Michał michal.no...@me.com:
How many rows do you have in that table?
a9-dev= select count(*) from records;
count
-
3620311
(1 row)
a9-dev= select source_id, count(*) from records where source_id =
'http://ebuw.uw.edu.pl/dlibra/oai-pmh-repository.xml' or
Setting statistics to 1000 on id and source_id didn't solve my problem:
a9-dev= explain analyze select * from records where source_id
='http://ebuw.uw.edu.pl/dlibra/oai-pmh-repository.xml' order by id limit 200;
QUERY PLAN
Please compare costs and actual times in those queries:
a9-dev= explain analyze select * from records where source_id
='http://www.wbc.poznan.pl/dlibra/oai-pmh-repository.xml' order by id limit 200;
QUERY PLAN
How can i get record by data block not by sql?
I want to read and write lots of data by data blocks and write record to a
appointed data block and read it.
so i can form a disk-resident tree by recording the block address. But i don't
know how to implement in postgresql.
Is there system
On Oct 3, 2011, at 6:52 AM, 姜头 wrote:
How can i get record by data block not by sql?
I want to read and write lots of data by data blocks and write record to a
appointed data block and read it.
so i can form a disk-resident tree by recording the block address. But i
don't know how to
a9-dev= explain analyze select * from records where source_id
='http://www.wbc.poznan.pl/dlibra/oai-pmh-repository.xml' order by id limit
200;
QUERY PLAN
=?iso-8859-2?Q?Nowak_Micha=B3?= michal.no...@me.com writes:
When I perform query such as this: select * from records where source_id =
'XXX' order by id limit 200; I expect DB to use index source_id_id_idx with
XXX as filter. It is true for all but one values of XXX - when I ask for
Venkat Balaji venkat.bal...@verse.in wrote:
We CLUSTERED a table using mostly used Index. Application is
performing better now.
CLUSTER can help in at least four ways:
(1) It eliminates bloat in the table heap.
(2) It eliminates bloat in the indexes.
(3) It can correct fragmentation
Thanks a lot Kevin !
This email has deepened my understanding on the clustering concept.
Keeping this in mind, I have recommended a new disk layout at the OS level
for our production servers so that IOs will be balanced on the disks as
well.
Currently, we do not have mount points divided
2011/10/3 Nowak Michał michal.no...@me.com:
Some info about data distrubution:
a9-dev= select min(id) from records;
min
190830
(1 row)
a9-dev= select min(id), max(id) from records where
source_id='http://ebuw.uw.edu.pl/dlibra/oai-pmh-repository.xml';
min | max
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