Re: alter table xxx set unlogged take long time

On Tue, Jul 26, 2022 at 4:53 AM James Pang (chaolpan) <chaolpan@cisco.com>
wrote:

> Hi ,
>
> We have PG v13.6 in RHEL8.4, we try to set table unlogged before load
> data.  There are a lot of existing data in this table, when ‘alter table
> xxx  set unlogged’, we found it take long time and spend time on IO
> datafileread.  Is it expected?
>
>
>
Yes, the whole table needs to be written to WAL so this could take a long
time for a large table