Re: [PERFORM] updating a row in a table with only one row

2009-10-12 Thread Merlin Moncure
On Mon, Oct 12, 2009 at 5:23 AM, Michal Vitecek wrote: > Merlin Moncure wrote: >>On Tue, Oct 6, 2009 at 10:59 AM, Michal Vitecek wrote: >>> Merlin Moncure wrote: On Mon, Oct 5, 2009 at 5:17 AM, Michal Vitecek wrote: >  Could the problem be the HW RAID card? There's ServerRAID 8k wit

Re: [PERFORM] updating a row in a table with only one row

2009-10-12 Thread Michal Vitecek
Merlin Moncure wrote: >On Tue, Oct 6, 2009 at 10:59 AM, Michal Vitecek wrote: >> Merlin Moncure wrote: >>>On Mon, Oct 5, 2009 at 5:17 AM, Michal Vitecek wrote: >>>  Could the problem be the HW RAID card? There's ServerRAID 8k with 256MB  with write-back enabled. Could it be that its int

Re: [PERFORM] updating a row in a table with only one row

2009-10-06 Thread Craig James
Merlin Moncure wrote: On Tue, Oct 6, 2009 at 10:59 AM, Michal Vitecek wrote: Merlin Moncure wrote: On Mon, Oct 5, 2009 at 5:17 AM, Michal Vitecek wrote: Could the problem be the HW RAID card? There's ServerRAID 8k with 256MB with write-back enabled. Could it be that its internal cache bec

Re: [PERFORM] updating a row in a table with only one row

2009-10-06 Thread Merlin Moncure
On Tue, Oct 6, 2009 at 10:59 AM, Michal Vitecek wrote: > Merlin Moncure wrote: >>On Mon, Oct 5, 2009 at 5:17 AM, Michal Vitecek wrote: >> >>>  Could the problem be the HW RAID card? There's ServerRAID 8k with 256MB >>>  with write-back enabled. Could it be that its internal cache becomes >>>  ful

Re: [PERFORM] updating a row in a table with only one row

2009-10-06 Thread Michal Vitecek
Merlin Moncure wrote: >On Mon, Oct 5, 2009 at 5:17 AM, Michal Vitecek wrote: > >>  Could the problem be the HW RAID card? There's ServerRAID 8k with 256MB >>  with write-back enabled. Could it be that its internal cache becomes >>  full and all disk I/O operations are delayed until it writes all >

Re: [PERFORM] updating a row in a table with only one row

2009-10-05 Thread Merlin Moncure
On Mon, Oct 5, 2009 at 5:17 AM, Michal Vitecek wrote: >  Could the problem be the HW RAID card? There's ServerRAID 8k with 256MB >  with write-back enabled. Could it be that its internal cache becomes >  full and all disk I/O operations are delayed until it writes all >  changes to hard drives?

Re: [PERFORM] updating a row in a table with only one row

2009-10-05 Thread Michal Vitecek
Robert Haas wrote: >On Fri, Oct 2, 2009 at 9:54 AM, Merlin Moncure wrote: >> On Fri, Oct 2, 2009 at 4:18 AM, Michal Vitecek wrote: >>>  Hello everyone, >>> >>>  I'm using PostgreSQL 8.3.8 running on a server with 2 Xeon CPUs, 4GB >>>  RAM, 4+2 disks in RAID 5 and CentOS 5.3. There's only one data

Re: [PERFORM] updating a row in a table with only one row

2009-10-02 Thread Heikki Linnakangas
Robert Haas wrote: > On Fri, Oct 2, 2009 at 9:54 AM, Merlin Moncure wrote: >> On Fri, Oct 2, 2009 at 4:18 AM, Michal Vitecek wrote: >>> Hello everyone, >>> >>> I'm using PostgreSQL 8.3.8 running on a server with 2 Xeon CPUs, 4GB >>> RAM, 4+2 disks in RAID 5 and CentOS 5.3. There's only one dat

Re: [PERFORM] updating a row in a table with only one row

2009-10-02 Thread Merlin Moncure
On Fri, Oct 2, 2009 at 1:39 PM, Robert Haas wrote: > On Fri, Oct 2, 2009 at 9:54 AM, Merlin Moncure wrote: >> it is ridiculous.  your problem is almost definitely dead rows.  I >> can't recall (and I can't find the info anywhere) if the 'hot' feature >> requires an index to be active -- I think i

Re: [PERFORM] updating a row in a table with only one row

2009-10-02 Thread Robert Haas
On Fri, Oct 2, 2009 at 9:54 AM, Merlin Moncure wrote: > On Fri, Oct 2, 2009 at 4:18 AM, Michal Vitecek wrote: >>  Hello everyone, >> >>  I'm using PostgreSQL 8.3.8 running on a server with 2 Xeon CPUs, 4GB >>  RAM, 4+2 disks in RAID 5 and CentOS 5.3. There's only one database >>  which dumped wit

Re: [PERFORM] updating a row in a table with only one row

2009-10-02 Thread Merlin Moncure
On Fri, Oct 2, 2009 at 4:18 AM, Michal Vitecek wrote: >  Hello everyone, > >  I'm using PostgreSQL 8.3.8 running on a server with 2 Xeon CPUs, 4GB >  RAM, 4+2 disks in RAID 5 and CentOS 5.3. There's only one database >  which dumped with pgdump takes ~0.5GB. > >  There are ~100 tables in the datab

Re: [PERFORM] updating a row in a table with only one row

2009-10-02 Thread Hélder M . Vieira
There are ~100 tables in the database and one of them (tableOne) always contains only a single row. There's one index on it. However performing update on the single row (which occurs every 60 secs) takes a considerably long time -- around 200ms. The system is not loaded in any way. How often is

Re: [PERFORM] updating a row in a table with only one row

2009-10-02 Thread A. Kretschmer
In response to Michal Vitecek : > There are ~100 tables in the database and one of them (tableOne) always > contains only a single row. There's one index on it. However performing In this case, only one row, you don't need an index. Really. > update on the single row (which occurs every 60 sec

[PERFORM] updating a row in a table with only one row

2009-10-02 Thread Michal Vitecek
Hello everyone, I'm using PostgreSQL 8.3.8 running on a server with 2 Xeon CPUs, 4GB RAM, 4+2 disks in RAID 5 and CentOS 5.3. There's only one database which dumped with pgdump takes ~0.5GB. There are ~100 tables in the database and one of them (tableOne) always contains only a single row.