Re: Naming-scheme for db-files

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От Markus Wollny
Тема Re: Naming-scheme for db-files
Дата
Msg-id 2266D0630E43BB4290742247C8910575014CE3AE@dozer.computec.de
обсуждение исходный текст
Ответ на Naming-scheme for db-files  ("Markus Wollny" <Markus.Wollny@computec.de>)
Список pgsql-general
Hi!

Unfortunately I cannot send the requested data, as I have already
dropped the original table. I think it might not be attributable to the
column itself, but to some other problem, which has been resolved by
copying the data from the original table to another one and then
dropping the original. In order to find out the size of the table, I
used "dir -h -S -r" in the database-directory and then looked up the
last relations via oid2name.

"select version()"-output: PostgreSQL 7.2.1 on i686-pc-linux-gnu,
compiled by GCC 2.95.3;

The emailindex-column was in fact empty - creating it was more or less
due to a misunderstanding :) So it never actually got used, but I didn't
go through the trouble of dropping it before yesterday. as I thought it
wouldn't do any harm (which was probably nevertheless correct). I'll
monitor growth of that table more closely now as this symptom might well
occur again  - I cannot imagine either that it could have something to
do with a totally empty column, no matter what datatype (char(n) beeing
an obvious exception).

Regards,

    Markus

> -----Ursprungliche Nachricht-----
> Von: Oleg Bartunov [mailto:oleg@sai.msu.su]
> Gesendet: Donnerstag, 29. August 2002 12:42
> An: Markus Wollny
> Cc: Martijn van Oosterhout; pgsql-general@postgresql.org
> Betreff: Re: [GENERAL] Naming-scheme for db-files
>
>
> I didn't follow this thread, but I'm a little bit surprised !
> txtdix itself is just a parsed data from corresponding column !
> and txtidx stores only unique lexems, so size of txtidx column should
> be lesser than original one ! I'd be interested to see more details
> (if you could send me your data and sql script). Also,
> did you use oid2name from contrib to see sizes of tables and indices ?
> What is an output of 'select version()' ?
> 100,000 rows is not a big deal.
>
>     regards,
>
>         Oleg
>
>
> On Thu, 29 Aug 2002, Markus Wollny wrote:
>
> > Just a try on using txtidx for a speedy search over the
> e-mail-fields.
> > No success, though - fti would have been better for the task (like
> > finding all users who have got an aol.com-adress).
> >
> > > -----UrsprNngliche Nachricht-----
> > > Von: Martijn van Oosterhout [mailto:kleptog@svana.org]
> > > Gesendet: Donnerstag, 29. August 2002 01:18
> > > An: Markus Wollny
> > > Cc: pgsql-general@postgresql.org
> > > Betreff: Re: [GENERAL] Naming-scheme for db-files
> > >
> > >
> > > On Wed, Aug 28, 2002 at 11:25:44PM +0200, Markus Wollny wrote:
> > > > After dropping the mentioned column emailindex of type
> txtidx (via
> > > > copying the data to a temporary table and renaming this table
> > > > afterwards), disk usage of that table evaporated from
> > > 1862MB to a humble
> > > > 61MB. And emailindex was completely empty... Very strange,
> > > but ~60MB is
> > > > very much more more like what I had estimated the size of
> > > that table to
> > > > be.
> > >
> > > What on earth is:
> > >
> > > emailindex txtidx,
> > >
> > > Anyway?
> > >
> > > >     -----UrsprУМngliche Nachricht-----
> > > >     Von: Markus Wollny
> > > >     Gesendet: Mi 28.08.2002 17:04
> > > >     An: Martijn van Oosterhout
> > > >     Cc: pgsql-general@postgresql.org
> > > >     Betreff: Re: [GENERAL] Naming-scheme for db-files
> > > >
> > > >
> > > >
> > > >     Hi!
> > > >
> > > >     Yes, I run vacuum every night - and log-output
> indicates no
> > > > errors at
> > > >     all. Yet I am indeed quite puzzled about the
> size of this table.
> > > > Is
> > > >     there some way of finding out which column
> consumes so much
> > > > space?
> > > >
> > > >     select count(*) from ct_com_user return 95858 rows.
> > > >     The CREATE-statement for this table is as follows:
> > > >
> > > >     CREATE TABLE ct_com_user (
> > > >       user_id numeric(10, 0),
> > > >       login varchar(1000),
> > > >       password varchar(1000),
> > > >       status numeric(10, 0),
> > > >       rights varchar(20) DEFAULT 'r',
> > > >       firstname varchar(1000),
> > > >       firstname_visible numeric(1, 0) DEFAULT 0,
> > > >       lastname varchar(1000),
> > > >       lastname_visible numeric(1, 0) DEFAULT 0,
> > > >       clan varchar(1000),
> > > >       clan_visible numeric(1, 0) DEFAULT 0,
> > > >       street varchar(1000),
> > > >       street_visible numeric(1, 0) DEFAULT 0,
> > > >       zipcode varchar(1000),
> > > >       zipcode_visible numeric(1, 0) DEFAULT 0,
> > > >       city varchar(1000),
> > > >       city_visible numeric(1, 0) DEFAULT 0,
> > > >       country varchar(1000),
> > > >       country_visible numeric(1, 0) DEFAULT 0,
> > > >       phone1 varchar(1000),
> > > >       phone1_visible numeric(1, 0) DEFAULT 0,
> > > >       phone2 varchar(1000),
> > > >       phone2_visible numeric(1, 0) DEFAULT 0,
> > > >       mobile varchar(1000),
> > > >       mobile_visible numeric(1, 0) DEFAULT 0,
> > > >       fax varchar(1000),
> > > >       fax_visible numeric(1, 0) DEFAULT 0,
> > > >       email1 varchar(1000),
> > > >       email1_visible numeric(1, 0) DEFAULT 0,
> > > >       email2 varchar(1000),
> > > >       email2_visible numeric(1, 0) DEFAULT 0,
> > > >       icq varchar(1000),
> > > >       icq_visible numeric(1, 0) DEFAULT 0,
> > > >       homepage varchar(1000),
> > > >       homepage_visible numeric(1, 0) DEFAULT 0,
> > > >       description varchar(1000),
> > > >       description_visible numeric(1, 0) DEFAULT 0,
> > > >       hobbies varchar(1000),
> > > >       hobbies_visible numeric(1, 0) DEFAULT 0,
> > > >       signature1 varchar(4000),
> > > >       signature2 varchar(4000),
> > > >       signature3 varchar(4000),
> > > >       forum_view varchar(20) DEFAULT 'flat',
> > > >       temp_password varchar(100),
> > > >       registered timestamptz,
> > > >       last_login timestamptz,
> > > >       created timestamptz DEFAULT
> ('now'::text)::timestamp(6) with
> > > > time
> > > >     zone,
> > > >       lines numeric(3, 0) DEFAULT 400,
> > > >       lines_forum numeric(3, 0) DEFAULT 20,
> > > >       forum_lines numeric(3, 0) DEFAULT 20,
> > > >       forum_smileys varchar(50) DEFAULT 'enhanced',
> > > >       site_id numeric(10, 0) DEFAULT 0,
> > > >       flag_id numeric(10, 0) DEFAULT 0,
> > > >       forum_quoting varchar(50) DEFAULT 'enhanced',
> > > >       forum_flatpostings numeric(3, 0) DEFAULT 10,
> > > >       forum_images numeric(1, 0) DEFAULT 2,
> > > >       user_image numeric(1, 0) DEFAULT 0,
> > > >       user_image_visible numeric(1, 0) DEFAULT 0,
> > > >       chat_password varchar(50),
> > > >       chat_last_visit timestamptz,
> > > >       authorpoints_visible numeric(1, 0) DEFAULT 0,
> > > >       emailindex txtidx,
> > > >       CONSTRAINT idx_pk_ct_com_user UNIQUE (user_id),
> > > >       CONSTRAINT idx_u_ct_com_user_login UNIQUE (login)
> > > >     ) WITH OIDS;
> > > >
> > > >     As hardly anyone actually uses a signature, hobby or
> > > > description, I
> > > >     cannot imagine how this should amount to almost
> 2 GB of data
> > > > (1862MB) -
> > > >     this would mean roughly 20k of data per row
> average - and no way
> > > > have we
> > > >     got this amount of data - the absolute maximum
> data per row as
> > > > defined
> > > >     would be about 30k, I guess, but that would
> mean that nearly all
> > > > of our
> > > >     users would use nearly all available space and
> I know that this
> > > > is quite
> > > >     far from true. I suspect it may have something
> to do with
> > > > emailindex of
> > > >     the txtidx-type... As it's not absolutely
> necessary, I'll try
> > > > and drop
> > > >     this column and see what I get...
> > > >
> > > >     Regards,
> > > >
> > > >             Markus
> > > >
> > > >     > -----UrsprУМngliche Nachricht-----
> > > >     > Von: Martijn van Oosterhout [mailto:kleptog@svana.org]
> > > >     > Gesendet: Mittwoch, 28. August 2002 16:30
> > > >     > An: Markus Wollny
> > > >     > Cc: pgsql-general@postgresql.org
> > > >     > Betreff: Re: [GENERAL] Naming-scheme for db-files
> > > >     >
> > > >     >
> > > >     > On Wed, Aug 28, 2002 at 03:54:45PM +0200,
> Markus Wollny wrote:
> > > >     > > Hi!
> > > >     > >
> > > >     > > As I was just checking disk-usage of a
> database (PostgreSQL
> > > >     > 7.2.1), I
> > > >     > > stumbled over some files named with a
> trailing .1 added to
> > > > the usual
> > > >     > > oid. Now if a table 'example' with oid
> 12345 exists, what
> > > >     > does the file
> > > >     > > 12345.1 contain exactly? I didn't find
> anything about
> > > >     > .1-files in the
> > > >     > > documentation...
> > > >     >
> > > >     > Postgres splits files at 1GB. The .1 file
> would be the second
> > > >     > part of the
> > > >     > file. When that also reaches 1GB, you'll get
> a .2 file.
> > > >     >
> > > >     > You're doing VACUUM [FULL] regularly, right?
> > > >     >
> > > >     > --
> > > >     > Martijn van Oosterhout   <kleptog@svana.org>
> > > >     > http://svana.org/kleptog/
> > > >     > > There are 10 kinds of people in the world,
> those that can do
> > > > binary
> > > >     > > arithmetic and those that can't.
> > > >     >
> > > >
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> > > > broadcast)---------------------------
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> > > > command
> > > >         (send "unregister YourEmailAddressHere" to
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> > > >
> > > >
> > > >
> > > > ---------------------------(end of
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> > >
> > > --
> > > Martijn van Oosterhout   <kleptog@svana.org>
> > > http://svana.org/kleptog/
> > > > There are 10 kinds of people in the world, those that
> can do binary
> > > > arithmetic and those that can't.
> > >
> >
> > ---------------------------(end of
> broadcast)---------------------------
> > TIP 5: Have you checked our extensive FAQ?
> >
> > http://www.postgresql.org/users-lounge/docs/faq.html
> >
>
>     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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