Hello
please, can you attach a value of shadow_buffers and work_mem from config
file?
Windows are very sensitive on memory setting. There must be lot of memory
just for MS Windows.
Regards
Pavel Stehule
2011/4/20 Allen Sooredoo
> Hi,
> we are facing a performance issue on Postgres 8.4, the C
Hi,
we are facing a performance issue on Postgres 8.4, the CPU reaches 100%
with less than 50 simultaneous users.
We were thinking to migrate the HR system from Oracle to Postgres but now
that we have those big performance problems on relatively small
applications, we are questioning this choic
Josh Berkus writes:
>> timestamptz + interval is not immutable --- in fact, the particular
>> example you give (ts + '1 day') is certainly dependent on timezone
>> setting.
> Why not? Given that the time zone will be the same for both the
> timestamptz and the interval, how would the result not
> You may be thinking of the STABLE volatility level. It requires that
> the results of the function are the same for the same inputs, within
> the same transaction.
Right. But CE will only pay attention to immutable values, not stable
ones, AFAICT.
--
Josh Berkus
PostgreSQL Experts Inc.
http
On 21 April 2011 12:13, Josh Berkus wrote:
>> Emphasis on "always". If the result of the function, given the same
>> argument values, can be different after a SET, then it doesn't qualify
>> for immutability. At least, that's my understanding.
>
> H. But within the context of the query plan
So sometime along yellow brick firmware road HP changed (and maybe your
vendor did too) the output of what happens when the write cache is off due
to failed batteries attached to the card/cache. (and no they don't always
beep with a self test in case someone happens to be walking near your cage,
an
> Emphasis on "always". If the result of the function, given the same
> argument values, can be different after a SET, then it doesn't qualify
> for immutability. At least, that's my understanding.
H. But within the context of the query plan itself, the results of
that expression are going
On 21 April 2011 11:58, Josh Berkus wrote:
>> timestamptz + interval is not immutable --- in fact, the particular
>> example you give (ts + '1 day') is certainly dependent on timezone
>> setting.
>
> Why not? Given that the time zone will be the same for both the
> timestamptz and the interval, h
Tom,
> timestamptz + interval is not immutable --- in fact, the particular
> example you give (ts + '1 day') is certainly dependent on timezone
> setting.
Why not? Given that the time zone will be the same for both the
timestamptz and the interval, how would the result not be immutable?
--
Jos
Josh Berkus writes:
> I understand why now() is a problem for CE, but I'd expect that it could
> at least handle a simple expression with immutable outputs.
timestamptz + interval is not immutable --- in fact, the particular
example you give (ts + '1 day') is certainly dependent on timezone
setti
All,
Apparently our CE is unable to deal with even moderately complex
expressions. For example, given a CE check constraint of:
"chk_start" CHECK (start >= '2011-01-31 00:00:00-05'::timestamp with
time zone AND start < '2011-03-01 00:00:00-05'::timestamp with time zone)
PostgreSQL CE is una
On 04/20/2011 09:01 AM, Laurent Laborde wrote:
A review of the V+100 on the excellent anandtech :
http://www.anandtech.com/show/4010/kingston-ssdnow-v-plus-100-review
That's horrifying. 4.9MB/s random writes? 19.7MB/s random reads? That's
at least an order of magnitude lower than other SSDs o
On Wed, Apr 20, 2011 at 2:39 PM, Jeff wrote:
>
> The performance here looks like the old jmicron based ssds that had
> absolutely abysmal performance - the intel x25s do not suffer like this. The
> x25's however suffer from the power durability Greg has mentioned. (And
> they will eventually need
Willy-Bas Loos writes:
> [ NOT field1 ISNULL is not seen as equivalent to field1 IS NOT NULL ]
> Any ideas why this might be?
The planner does not spend an infinite number of cycles on trying to
make different expressions look alike.
As it happens, 9.1 does know this equivalence, as a byproduct
On Apr 19, 2011, at 8:49 AM, Laurent Laborde wrote:
Write Mode: 10%
Stallcheck at 1.00
Verbose
Unknown units of blocks
Arg: 1
Read 100 blocks
Added /home/ssd/big1
2.01%, 20122 read, 1978 written, 16097.57kB/sec 2012.20 iops
2.01%, 3 read, 0 written,2.40kB/sec0.30 io
Hi,
I'm using PostgreSQL 8.4 (and also 8.3).
A partial index like this:
CREATE INDEX table2_field1_idx
ON table2 (field1)
WHERE NOT field1 ISNULL;
Will not be used when select one record from 100K records:
explain select * from table2 where field1 = 256988
'Seq Scan on table2 (cost=0.00..16
random_page_cost with a value set to "2" and it works fine
Thanks for your help
2011/3/1 Maciek Sakrejda
> On Tue, Mar 1, 2011 at 4:44 AM, Joby Joba wrote:
> > Me again ! I have checked this question of 'explain analyze' and I
> > understand now.
> >
> > When the problem occured I have run a
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