Thread: Wal_keep_segment value too high

Wal_keep_segment value too high

From
Brajendra Pratap Singh
Date:
Hi,

What will happen if the wal_keep_segments value is too high ,is this affect the database performance anyhow like checkpoint and all or is there because of this any delay in the replication sync or wal records transfer from primary to replication postgresql db?

Thanks,
Brajendra

Re: Wal_keep_segment value too high

From
Andreas Kretschmer
Date:
On 10 July 2020 10:26:25 CEST, Brajendra Pratap Singh <singh.bpratap766@gmail.com> wrote:
>Hi,
>
>What will happen if the wal_keep_segments value is too high ,is this

wasted disk space.

What do you want to achive?


Regards, Andreas


--
2ndQuadrant - The PostgreSQL Support Company



Re: Wal_keep_segment value too high

From
Brajendra Pratap Singh
Date:
Hi Andreas,

Actually there will be sync gap almost 3-4hours during the ETL jobs between primary and streaming replication db ,so I just want to make sure is there any affect in replication bcoz of high value of wal_keep_segments .

Second thing we have implemented pgbackrest in archive_command so archive name will generate in zipped format along with some binary so what will be the restore_command for that if we lose any wals from wal directory of primary db and how it will be applying to replication db via restore_command means is it require password less ssh between primary and replica.

Third thing is the high value of wal_keep_segment anyhow affect the checkpoint operation ,dml operation,select query or data write operation from memory to disk?

Thanks,
Brajendra


On Fri, 10 Jul, 2020, 5:44 PM Andreas Kretschmer, <andreas@a-kretschmer.de> wrote:
On 10 July 2020 10:26:25 CEST, Brajendra Pratap Singh <singh.bpratap766@gmail.com> wrote:
>Hi,
>
>What will happen if the wal_keep_segments value is too high ,is this

wasted disk space.

What do you want to achive?


Regards, Andreas


--
2ndQuadrant - The PostgreSQL Support Company