WAL logs and segment files

[Eduardo Leva]

Hi, guys... I'm reading the version 7.3.4 documentation and I found this: "

"WAL logs are stored in the directory $PGDATA/pg_xlog, as a set of segment
files, each 16 MB in size. Each segment is divided into 8 kB pages. The
log record headers are described in access/xlog.h; record content is
dependent on the type of event that is being logged. Segment files are
given ever-increasing numbers as names, starting at 0000000000000000. The
numbers do not wrap, at present, but it should take a very long time to
exhaust the available stock of numbers. "

in item 12.2 Implementation. The question is: How do I solve this
situation, the remarked situation? The answer is not in the docs. Thanks.

Pd. Sorry about my poor english. I speak spanish every day of my 3rd.
world's life...
Sigan adelante... Saludos.

Eduardo Leva
Programador
Santa Fe Argentina.

[Bruce Momjian]

Post by Eduardo Leva
Hi, guys... I'm reading the version 7.3.4 documentation and I found this: "
"WAL logs are stored in the directory $PGDATA/pg_xlog, as a set of segment
files, each 16 MB in size. Each segment is divided into 8 kB pages. The
log record headers are described in access/xlog.h; record content is
dependent on the type of event that is being logged. Segment files are
given ever-increasing numbers as names, starting at 0000000000000000. The
numbers do not wrap, at present, but it should take a very long time to
exhaust the available stock of numbers. "
in item 12.2 Implementation. The question is: How do I solve this
situation, the remarked situation? The answer is not in the docs. Thanks.

What situation do you need to solve? The wrapping? The documention
states "a very long time", but it more of a joke. That number would be
huge to wrap around and you would be updating your PostgreSQL version
long before it would ever wrap.

The number is actually an int8 that has a maximum value of:

18446744073709551616

[kaolin fire]

If you know where I can get a 1.5e+11 terabyte drive, I'd love to hear
it. ;)

-kaolin fire
-http://erif.org/code/fallingup/

Post by Bruce Momjian

Post by Eduardo Leva
Hi, guys... I'm reading the version 7.3.4 documentation and I found this: "
"WAL logs are stored in the directory $PGDATA/pg_xlog, as a set of segment
files, each 16 MB in size. Each segment is divided into 8 kB pages. The
log record headers are described in access/xlog.h; record content is
dependent on the type of event that is being logged. Segment files are
given ever-increasing numbers as names, starting at
0000000000000000. The
numbers do not wrap, at present, but it should take a very long time to
exhaust the available stock of numbers. "
in item 12.2 Implementation. The question is: How do I solve this
situation, the remarked situation? The answer is not in the docs. Thanks.

What situation do you need to solve? The wrapping? The documention
states "a very long time", but it more of a joke. That number would be
huge to wrap around and you would be updating your PostgreSQL version
long before it would ever wrap.
18446744073709551616
--
Bruce Momjian | http://candle.pha.pa.us
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073
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[scott]

Take me off your list! You have the wrong scott!
----- Original Message -----
From: "Bruce Momjian" <***@candle.pha.pa.us>
To: "Eduardo Leva" <***@netscape.net>
Cc: <pgsql-***@postgresql.org>
Sent: Friday, February 20, 2004 12:29 PM
Subject: Re: [ADMIN] WAL logs and segment files

Post by Bruce Momjian

Post by Eduardo Leva
Hi, guys... I'm reading the version 7.3.4 documentation and I found this: "
"WAL logs are stored in the directory $PGDATA/pg_xlog, as a set of segment
files, each 16 MB in size. Each segment is divided into 8 kB pages. The
log record headers are described in access/xlog.h; record content is
dependent on the type of event that is being logged. Segment files are
given ever-increasing numbers as names, starting at 0000000000000000. The
numbers do not wrap, at present, but it should take a very long time to
exhaust the available stock of numbers. "
in item 12.2 Implementation. The question is: How do I solve this
situation, the remarked situation? The answer is not in the docs. Thanks.

What situation do you need to solve? The wrapping? The documention
states "a very long time", but it more of a joke. That number would be
huge to wrap around and you would be updating your PostgreSQL version
long before it would ever wrap.
18446744073709551616
--
Bruce Momjian | http://candle.pha.pa.us
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073
---------------------------(end of broadcast)---------------------------
TIP 9: the planner will ignore your desire to choose an index scan if your
joining column's datatypes do not match

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