Re: row filtering for logical replication - Mailing list pgsql-hackers

From Peter Smith
Subject Re: row filtering for logical replication
Date
Msg-id CAHut+PuGgeme_XLQ3FGg8foN=+XYHvU8tVZJ=PrjoMJ07x-hhw@mail.gmail.com
Whole thread Raw
In response to Re: row filtering for logical replication  (vignesh C <vignesh21@gmail.com>)
List pgsql-hackers
On Tue, Nov 30, 2021 at 9:34 PM vignesh C <vignesh21@gmail.com> wrote:
>
...
> Thanks for the updated patch, few comments:
> 1) Should this be changed to include non IMMUTABLE system functions
> are not allowed:
> +   not-null constraints in the <literal>WHERE</literal> clause. The
> +   <literal>WHERE</literal> clause does not allow functions or user-defined
> +   operators.
> +  </para>
>

Updated docs in v44 [1]

> 2) We can remove the #if 0 code if we don't plan to keep it in the final patch.
> --- a/src/backend/parser/parse_agg.c
> +++ b/src/backend/parser/parse_agg.c
> @@ -552,11 +552,12 @@ check_agglevels_and_constraints(ParseState
> *pstate, Node *expr)
>
>                         break;
>                 case EXPR_KIND_PUBLICATION_WHERE:
> +#if 0
>                         if (isAgg)
>                                 err = _("aggregate functions are not
> allowed in publication WHERE expressions");
>                         else
>                                 err = _("grouping operations are not
> allowed in publication WHERE expressions");
> -
> +#endif
>

Fixed in v44 [1]

> 4) Should this be changed, since we error out if publisher without
> replica identify performs delete or update:
> +   The <literal>WHERE</literal> clause must contain only columns that are
> +   covered  by <literal>REPLICA IDENTITY</literal>, or are part of the primary
> +   key (when <literal>REPLICA IDENTITY</literal> is not set), otherwise
> +   <command>DELETE</command> or <command>UPDATE</command> operations will not
> +   be replicated. That's because old row is used and it only contains primary
> +   key or columns that are part of the <literal>REPLICA IDENTITY</literal>; the
> +   remaining columns are <literal>NULL</literal>. For <command>INSERT</command>
>
> to:
> +   The <literal>WHERE</literal> clause must contain only columns that are
> +   covered  by <literal>REPLICA IDENTITY</literal>, or are part of the primary
> +   key (when <literal>REPLICA IDENTITY</literal> is not set), otherwise
> +   <command>DELETE</command> or <command>UPDATE</command> operations will be
> +   disallowed on those tables. That's because old row is used and it
> only contains primary
> +   key or columns that are part of the <literal>REPLICA IDENTITY</literal>; the
> +   remaining columns are <literal>NULL</literal>. For <command>INSERT</command>
>

Updated docs in v44 [1]

------
[1] https://www.postgresql.org/message-id/CAHut%2BPtjxzedJPbSZyb9pd72%2BUrGEj6HagQQbCdO0YJvr7OyJg%40mail.gmail.com

Kind Regards,
Peter Smith.
Fujitsu Australia



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