Re: [GENERAL] Needs Suggestion

2011-05-03 Thread Guillaume Lelarge
On 05/04/2011 08:39 AM, Andreas Kretschmer wrote: > SUBHAM ROY wrote: > >> My output of explain (analyze,buffers) is something like this: >> >> shared hit=3796624 read=46038 >> >> So what is meant by read here? Does it indicates number of disk reads? >> >> Does shared hit takes into account only

Re: [GENERAL] Needs Suggestion

2011-05-03 Thread Andreas Kretschmer
SUBHAM ROY wrote: > My output of explain (analyze,buffers) is something like this: > > shared hit=3796624 read=46038 > > So what is meant by read here? Does it indicates number of disk reads? > > Does shared hit takes into account only the hit in the pg_buffercache of the > postgres or it also

Re: [GENERAL] Needs Suggestion

2011-05-02 Thread Craig Ringer
On 04/28/2011 02:11 AM, SUBHAM ROY wrote: I am using postgres 8.4.8, the above command explain(analyze,buffers) is not working. Is there a way to do that. Nope, the (BUFFERS) syntax was added in 9.0. Try the other suggestions about using table stats to determine what you want to know. -- Cra

Re: [GENERAL] Needs Suggestion

2011-04-27 Thread SUBHAM ROY
I am using postgres 8.4.8, the above command explain(analyze,buffers) is not working. Is there a way to do that. -- Thank You, Subham Roy, CSE IIT Bombay.

Re: [GENERAL] Needs Suggestion

2011-04-27 Thread Magnus Hagander
On Wed, Apr 27, 2011 at 16:35, SUBHAM ROY wrote: > Can I calculate the Buffer Hit ratio of a particular query in postgres? That > is how many times it finds the required page in its buffer cache, > pg_buffercache or the > linux buffer cache. You can get the information from the pg cache using EXP

Re: [GENERAL] Needs Suggestion

2011-04-27 Thread Andy Colson
On 4/27/2011 9:35 AM, SUBHAM ROY wrote: Can I calculate the *Buffer Hit ratio* *of a particular query* in postgres? That is *how many times it finds the required page* in its buffer cache, pg_buffercache or the linux buffer cache. -- Thank You, Subham Roy, CSE IIT Bombay. There are plenty of

Re: [GENERAL] Needs Suggestion

2011-04-22 Thread SUBHAM ROY
Sorry, but I'm not able to understand about how to use pgsnap for measuring query performance. I have installed pgsnap. when I run pgsnap it shows some error: *Connecting to test database... Adding some HTML files... Getting Misc informations... Getting General informations... sh: pg_controldata:

Re: [GENERAL] Needs Suggestion

2011-04-21 Thread Alban Hertroys
On 20 Apr 2011, at 19:11, SUBHAM ROY wrote: > By doing \timing in psql, we enable the timing and then when we type the > query we are able to see its execution time. > Similarly, is there any way to view the number I/Os and memory usage by a > particular query. You seem to be unfamiliar with t

Re: [GENERAL] Needs Suggestion

2011-04-20 Thread raghu ram
On Wed, Apr 20, 2011 at 10:41 PM, SUBHAM ROY wrote: > By doing \timing in psql, we enable the timing and then when we type the > query we are able to see its execution time. > Similarly, is there any way to view the number I/Os and memory usage by a > particular query. > > PGsnap module will desc

Re: [GENERAL] Needs Suggestion

2011-04-19 Thread Scott Marlowe
On Tue, Apr 19, 2011 at 5:06 PM, SUBHAM ROY wrote: > Suppose Postgres is installed in two computers C1 & C2. > C1 have some database tables. How can I copy these database tables from C1 > to C2. > I mean to say that can I copy tables from postgres installed in one m/c to > another m/c. > Is there