postgres: writer process,what does this process actually do?

Started by Thomasover 16 years ago10 messagesgeneral
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#1Thomas
freebsdjlu@gmail.com

Does it write data to data files to make buffer "clean"?if it
does ,but I can not find open files from the result of lsof -p
PID.

#2Grzegorz Jaśkiewicz
gryzman@gmail.com
In reply to: Thomas (#1)
Re: postgres: writer process,what does this process actually do?

On Tue, Dec 22, 2009 at 10:19 AM, Thomas <freebsdjlu@gmail.com> wrote:

Does it write data to data files to make buffer "clean"?if it
does ,but I can not find open files from the result of lsof -p
 PID.

writer actually takes care about writing pages down, from shared
memory. It is the central point that accesses disk on behalf of all
backends (which are spawned every time you create new connection).

--
GJ

#3Thomas
freebsdjlu@gmail.com
In reply to: Thomas (#1)
Re: postgres: writer process,what does this process actually do?

On 12月22日, 下午11时26分, gryz...@gmail.com (Grzegorz Jaśkiewicz) wrote:

On Tue, Dec 22, 2009 at 10:19 AM, Thomas <freebsd...@gmail.com> wrote:

Does it write data to data files to make buffer "clean"?if it
does ,but I can not find open files from the result of lsof -p
 PID.

writer actually takes care about writing pages down, from shared
memory. It is the central point that accesses disk on behalf of all
backends (which are spawned every time you create new connection).

--
GJ

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hi GJ
Tks a lot .
And could you give me some info about postgres internals? Such as
ebooks or online articles.

#4Richard Broersma
richard.broersma@gmail.com
In reply to: Thomas (#3)
Re: postgres: writer process,what does this process actually do?

On Tue, Dec 22, 2009 at 6:56 PM, Thomas <freebsdjlu@gmail.com>ote:

And could you give me some info about postgres internals? Such as
ebooks or online articles.

I'm not sure if you've already reviewed this part of the PostgreSQL docs or not:

http://www.postgresql.org/docs/8.4/interactive/internals.html

--
Regards,
Richard Broersma Jr.

Visit the Los Angeles PostgreSQL Users Group (LAPUG)
http://pugs.postgresql.org/lapug

#5Jayadevan M
Jayadevan.Maymala@ibsplc.com
In reply to: Richard Broersma (#4)
PostgreSQL and character set change

Hi all,
We have a PostgreSQL server with ASCII data. We have a requirement for
the db to support UTF also. Which is the best approach -
1) Make a new installation, move data
2) There is some way of doing an 'in-place' conversion and changing the
character set of the existing installation
Please do provide some information on how to do this.
Jayadevan

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#6Pavel Stehule
pavel.stehule@gmail.com
In reply to: Jayadevan M (#5)
Re: PostgreSQL and character set change

2009/12/23 Jayadevan M <Jayadevan.Maymala@ibsplc.com>

Hi all,
We have a PostgreSQL server with ASCII data. We have a requirement for the
db to support UTF also. Which is the best approach -
1) Make a new installation, move data
2) There is some way of doing an 'in-place' conversion and changing the
character set of the existing installation
Please do provide some information on how to do this.
Jayadevan

1 is right.

Regards
Pavel Stehule

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or completeness of the information contained in this email or any attachment
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resultant loss or damage, if any, direct or indirect."

#7Laurenz Albe
laurenz.albe@cybertec.at
In reply to: Jayadevan M (#5)
Re: PostgreSQL and character set change

Jayadevan M wrote:

We have a PostgreSQL server with ASCII data. We have a
requirement for the db to support UTF also. Which is the best
approach -
1) Make a new installation, move data

This is the only and hence the best approach.
It doesn't have to be a new installation, a new database with
encoding UTF8 is enough.

Yours,
Laurenz Albe

#8Jayadevan M
Jayadevan.Maymala@ibsplc.com
In reply to: Laurenz Albe (#7)
Re: PostgreSQL and character set change

Hi,
Thanks.
For anyone else who may be looking for more information, please see
details on how to do it here....
http://docs.moodle.org/en/UTF-8_PostgreSQL#PostgreSQL_UTF8_Migration_How-to
Regards,
Jayadevan

From: "Albe Laurenz" <laurenz.albe@wien.gv.at>
To: "Jayadevan M *EXTERN*" <Jayadevan.Maymala@ibsplc.com>,
<pgsql-general@postgresql.org>
Date: 12/23/2009 01:12 PM
Subject: Re: [GENERAL] PostgreSQL and character set change
Sent by: pgsql-general-owner@postgresql.org

Jayadevan M wrote:

We have a PostgreSQL server with ASCII data. We have a
requirement for the db to support UTF also. Which is the best
approach -
1) Make a new installation, move data

This is the only and hence the best approach.
It doesn't have to be a new installation, a new database with
encoding UTF8 is enough.

Yours,
Laurenz Albe

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adequacy or completeness of the information contained in this email or any
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or for resultant loss or damage, if any, direct or indirect."

In reply to: Thomas (#3)
Re: postgres: writer process,what does this process actually do?

On 23/12/2009 02:56, Thomas wrote:

And could you give me some info about postgres internals? Such as
ebooks or online articles.

There's quite a bit in the manual:

http://www.postgresql.org/docs/8.4/interactive/internals.html

Ray.

--
Raymond O'Donnell :: Galway :: Ireland
rod@iol.ie

#10Thomas
freebsdjlu@gmail.com
In reply to: Thomas (#1)
Re: postgres: writer process,what does this process actually do?

On Dec 23, 3:44 pm, r...@iol.ie ("Raymond O'Donnell") wrote:

On 23/12/2009 02:56, Thomas wrote:

And could you give me some info about postgres internals? Such as
ebooks or online articles.

There's quite a bit in the manual:

 http://www.postgresql.org/docs/8.4/interactive/internals.html

Ray.

--
Raymond O'Donnell :: Galway :: Ireland
r...@iol.ie

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Tks man.
:)