Re: Synchronizing slots from primary to standby

On Thu, Jan 25, 2024 at 6:42 PM Zhijie Hou (Fujitsu)
<houzj.fnst@fujitsu.com> wrote:
>
> Here is the V69 patch set which includes the following changes.
>
> V69-0001, V69-0002
>

Few minor comments on v69-0001
1. In libpqrcv_create_slot(), I see we are using two types of syntaxes
based on 'use_new_options_syntax' (aka server_version >= 15) whereas
this new 'failover' option doesn't follow that. What is the reason of
the same? I thought it is because older versions anyway won't support
this option. However, I guess we should follow the syntax of the old
server and let it error out. BTW, did you test this patch with old
server versions (say < 15 and >=15) by directly using replication
commands, if so, what is the behavior of same?

2.
  }
-
+ if (failover)
+ appendStringInfoString(&cmd, "FAILOVER, ");

Spurious line removal. Also, to follow a coding pattern similar to
nearby code, let's have one empty line after handling of failover.

3.
+/* ALTER_REPLICATION_SLOT slot */
+alter_replication_slot:
+ K_ALTER_REPLICATION_SLOT IDENT '(' generic_option_list ')'

I think it would be better if we follow the create style by specifying
syntax in comments as that can make the code easier to understand
after future extensions to this command if any. See
create_replication_slot:
/* CREATE_REPLICATION_SLOT slot [TEMPORARY] PHYSICAL [options] */
K_CREATE_REPLICATION_SLOT IDENT opt_temporary K_PHYSICAL create_slot_options

--
With Regards,
Amit Kapila.