Ahmad,

what's about the number of unique words ? I mean stat() function.
Sometimes, it helps to identify garbage words.
How big is your articles (average length) ?

please, cut'n paste queries and output from psql ! How fast are next queries ?

        Oleg
On Fri, 23 Sep 2005, Ahmad Fajar wrote:

Hi Oleg,

For single index I try this query:
explain analyze
select articleid, title, datee from articles
where fti @@ to_tsquery('bank&indonesia');

analyze result:
----------------
"Index Scan using fti_idx on articles  (cost=0.00..862.97 rows=420 width=51)
(actual time=0.067..183761.324 rows=46186 loops=1)"
"  Index Cond: (fti @@ '\'bank\' & \'indonesia\''::tsquery)"
"Total runtime: 183837.826 ms"

And for multicolumn index I try this query:
explain analyze
select articleid, title, datee from articles
where fti @@ to_tsquery('bank&mega');

analyze result:
----------------
"Index Scan using articles_x1 on articles  (cost=0.00..848.01 rows=410
width=51) (actual time=52.204..37914.135 rows=1841 loops=1)"
"  Index Cond: ((datee >= '2002-01-01'::date) AND (datee <=
('now'::text)::date) AND (fti @@ '\'bank\' & \'mega\''::tsquery))"
"Total runtime: 37933.757 ms"

The table structure is as mention on the first talk. If you wanna know how
much table in my database, it's about 100 tables or maybe more. Now I
develop the version 2 of my web application, you can take a look at:
http://www.mediatrac.net, so it will hold many datas. But the biggest table
is article's table. On develop this version 2 I just use half data of the
article's table (about 419804 rows). May be if I import all of the article's
table data it will have 1 million rows. The article's table grows rapidly,
about 100000 rows per-week. My developing database size is 28 GB (not real
database, coz I still develop the version 2 and I use half of the data for
play around). I just wanna to perform quick search (fulltext search) on my
article's table not other table. On version 1, the current running version I
use same hardware spesification as mention below, but there is no fulltext
search. So I develop the new version with new features, new interface and
include the fulltext search.

I do know, if the application finish, I must use powerfull hardware. But how
can I guarantee the application will run smooth, if I do fulltext search on
419804 rows in a table it took a long time to get the result.

Could you or friends in this maling-list help me....plz..plzz

Tsearch2 configuration:
-------------------------
I use default configuration, english stop word file as tsearch2 provide,
stem dictionary as default (coz I don't know how to configure and add new
data to stem dictionary) and I add some words to the english stop word file.

Postgresql configuration
-------------------------
max_connections = 32
shared_buffers = 32768
sort_mem = 8192
vacuum_mem = 65536
work_mem = 16384
maintenance_work_mem = 65536
max_fsm_pages = 30000
max_fsm_relations = 1000
max_files_per_process = 100000
checkpoint_segments = 15
effective_cache_size = 192000
random_page_cost = 2
geqo = true
geqo_threshold = 50
geqo_effort = 5
geqo_pool_size = 0
geqo_generations = 0
geqo_selection_bias = 2.0
from_collapse_limit = 10
join_collapse_limit = 15

OS configuration:
------------------
I use Redhat 4 AS, kernel 2.6.9-11
kernel.shmmax=1073741824
kernel.sem=250 32000 100 128
fs.aio-max-nr=5242880
the server I configure just only for postgresql, no other service is running
like: www, samba, ftp, email, firewall

hardware configuration:
------------------------
Motherboard ASUS P5GD1
Processor P4 3,2 GHz
Memory 2 GB DDR 400,
2x200 GB Serial ATA 7200 RPM UltraATA/133, configure as RAID0 for postgresql
data and the partition is EXT3
1x80 GB EIDE 7200 RPM configure for system and home directory and the
partiton is EXT3

Did I miss something?

Regards,
ahmad fajar


-----Original Message-----
From: Oleg Bartunov [mailto:[EMAIL PROTECTED]
Sent: Jumat, 23 September 2005 18:26
To: Ahmad Fajar
Cc: pgsql-performance@postgresql.org
Subject: RE: [PERFORM] tsearch2 seem very slow

On Fri, 23 Sep 2005, Ahmad Fajar wrote:

Hi Oleg,

I didn't deny on the third repeat or more, it can reach < 600 msec. It is
only because the result still in postgres cache, but how about in the
first
run? I didn't dare, the values is un-acceptable. Because my table will
grows
rapidly, it's about 100000 rows per-week. And the visitor will search
anything that I don't know, whether it's the repeated search or new
search,
or whether it's in postgres cache or not.

if you have enoush shared memory postgresql will keep index pages there.



I just compare with http://www.postgresql.org, the search is quite fast,
and
I don't know whether the site uses tsearch2 or something else. But as fas
as
I know, if the rows reach >100 milion (I have try for 200 milion rows and
it
seem very slow), even if don't use tsearch2, only use simple query like:
select f1, f2 from table1 where f2='blabla',
and f2 is indexes, my postgres still slow on the first time, about >10
sec.
because of this I tried something brand new to fullfill my needs. I have
used fti, and tsearch2 but still slow.

I don't know what's going wrong with my postgres, what configuration must
I
do to perform the query get fast result. Or must I use enterprisedb 2005
or
pervasive postgres (both uses postgres), I don't know very much about
these
two products.

you didn't show us your configuration (hardware,postgresql and tsearch2),
explain analyze of your queries, so we can't help you.
How big is your database, tsearch2 index size ?



Regards,
ahmad fajar


-----Original Message-----
From: Oleg Bartunov [mailto:[EMAIL PROTECTED]
Sent: Jumat, 23 September 2005 14:36
To: Ahmad Fajar
Cc: pgsql-performance@postgresql.org
Subject: Re: [PERFORM] tsearch2 seem very slow

Ahmad,

how fast is repeated runs ? First time system could be very slow.
Also, have you checked my page
http://www.sai.msu.su/~megera/oddmuse/index.cgi/Tsearch_V2_Notes
and some info about tsearch2 internals
http://www.sai.msu.su/~megera/oddmuse/index.cgi/Tsearch_V2_internals

        Oleg
On Thu, 22 Sep 2005, Ahmad Fajar wrote:

I have about 419804 rows in my article table. I have installed tsearch2
and
its gist index correctly.

My table structure is:

CREATE TABLE tbarticles

(

 articleid int4 NOT NULL,

 title varchar(250),

 mediaid int4,

 datee date,

 content text,

 contentvar text,

 mmcol float4 NOT NULL,

 sirkulasi float4,

 page varchar(10),

 tglisidata date,

 namapc varchar(12),

 usere varchar(12),

 file_pdf varchar(255),

 file_pdf2 varchar(50),

 kolom int4,

 size_jpeg int4,

 journalist varchar(120),

 ratebw float4,

 ratefc float4,

 fti tsvector,

 CONSTRAINT pk_tbarticles PRIMARY KEY (articleid)

) WITHOUT OIDS;

Create index fti_idx1 on tbarticles using gist (fti);

Create index fti_idx2 on tbarticles using gist (datee, fti);



But when I search something like:

Select articleid, title, datee from tbarticles where fti @@
to_tsquery('susilo&bambang&yudhoyono&jusuf&kalla');

It takes about 30 sec. I run explain analyze and the index is used
correctly.



Then I try multi column index to filter by date, and my query something
like:

Select articleid, title, datee from tbarticles where fti @@
to_tsquery('susilo&bambang&yudhoyono&jusuf&kalla') and datee >=
'2002-01-01'
and datee <= current_date

An it still run about 25 sec. I do run explain analyze and my multicolumn
index is used correctly.

This is not acceptable if want to publish my website if the search took
very
longer.



I have run vacuum full analyze before doing such query. What going wrong
with my query?? Is there any way to make this faster?

I have try to tune my postgres configuration, but it seem helpless. My
linux
box is Redhat 4 AS, and

the hardware: 2 GB RAM DDR 400, 2x200 GB Serial ATA 7200RPM and configure
as
RAID0 (just for postgres data), my sistem run at EIDE 80GB 7200 RPM.



Please.help.help.



        Regards,
                Oleg
_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83


        Regards,
                Oleg
_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83


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        Regards,
                Oleg
_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83

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