Re: postgres wal log configuration question

Hello Experts,

Kindly provide feedback on my questions.

Thank you.

On Mon, May 6, 2019 at 2:25 PM Pavan Kumar <pavan(dot)dba27(at)gmail(dot)com> wrote:

> postgres wal log configuration question
>
> hello experts,
>
> I have couple of question on postgres wal log configuration.
>
> how do we know current wal log location and current wal segment name in
> postgres ? is there any query to to check location ?
>
>
> I ran the switch wal log command, as below
>
> postgres=# select pg_switch_wal();
> pg_switch_wal
> ---------------
> C/E000158
> (1 row)
>
> how do i understand the output ? Is this wal segment name ? If yes, when
> i look at wal log location i do see below output. how do i correlate query
> output with os command output ?
>
> postgres=# select pg_switch_wal();
> pg_switch_wal
> ---------------
> C/E000158
> (1 row)
>
> postgres=# \! ls -lart /oradbaudit/pg_data_dir/pg_wal|tail -5 >>>> last
> wal segments generated on wal location.
> lrwxrwxrwx. 1 postgres postgres 23 May 6 16:06
> /oradbaudit/pg_data_dir/pg_wal -> /oradbaudit/pg_wal_dir/
> postgres=# \! ls -lart /oradbaudit/pg_data_dir/pg_wal/|tail -5
> -rw-------. 1 postgres postgres 16777216 May 6 17:37
> 000000020000000C00000048
> drwx------. 3 postgres postgres 12288 May 6 17:41 .
> -rw-------. 1 postgres postgres 16777216 May 6 18:57
> 000000020000000C0000000E
> drwx------. 2 postgres postgres 125 May 6 18:57 archive_status
> -rw-------. 1 postgres postgres 16777216 May 6 18:57
> 000000020000000C0000000F
>
> Is there any way to provide meaning full sequence number for wal segments?
> looks like wal segment file name is generating random names. is there any
> way to control name format ?
>
> I noticed that file wal file name generated on $PGDATA/pg_wal location and
> archived location seem different. is this expected behavior ?
>
>
> please help me to understand this concept.
>
>
> --
>
>
>
> *Regards,#! Pavan Kumar----------------------------------------------*-
> *Sr. Database Administrator..!*
> *NEXT GENERATION PROFESSIONALS, LLC*
> *Cell # 267-799-3182 # pavan.dba27 (Gtalk) *
> *India # 9000459083*
>
> *Take Risks; if you win, you will be very happy. If you lose you will be
> Wise *
>
>

--

*Regards,#! Pavan Kumar----------------------------------------------*-
*Sr. Database Administrator..!*
*NEXT GENERATION PROFESSIONALS, LLC*
*Cell # 267-799-3182 # pavan.dba27 (Gtalk) *
*India # 9000459083*

*Take Risks; if you win, you will be very happy. If you lose you will be
Wise *