Re: row filtering for logical replication

On Thu, Jan 27, 2022 at 4:59 PM Peter Smith <smithpb2250(at)gmail(dot)com> wrote:
>
> On Thu, Jan 27, 2022 at 9:40 AM Greg Nancarrow <gregn4422(at)gmail(dot)com>
wrote:
> >
> > On Wed, Jan 26, 2022 at 2:08 PM houzj(dot)fnst(at)fujitsu(dot)com
> > <houzj(dot)fnst(at)fujitsu(dot)com> wrote:
> > >
> > > There was a miss in the posted patch which didn't initialize the
parameter in
> > > RelationBuildPublicationDesc, sorry for that. Attach the correct
patch this time.
> > >
> >
> > A few comments for the v71-0001 patch:
> ...
> > (2) check_simple_rowfilter_expr_walker
> >
> > In the function header:
> > (i) "etc" should be "etc."
> > (ii)
> > Is
> >
> > + * - (Var Op Const) Bool (Var Op Const)
> >
> > meant to be:
> >
> > + * - (Var Op Const) Logical-Op (Var Op Const)
> >
> > ?
> >
> > It's not clear what "Bool" means here.
>
> The comment is only intended as a generic example of the kinds of
> acceptable expression format.
>
> The names in the comment used are roughly equivalent to the Node* tag
names.
>
> This particular example is for an expression with AND/OR/NOT, which is
> handled by a BoolExpr.
>
> There is no such animal as LogicalOp, so rather than change like your
> suggestion I feel if this comment is going to change then it would be
> better to change to be "boolop" (because the BoolExpr struct has a
> boolop member). e.g.
>
> BEFORE
> + * - (Var Op Const) Bool (Var Op Const)
> AFTER
> + * - (Var Op Const) boolop (Var Op Const)
>

My use of "LogicalOp" was just indicating that the use of "Bool" in that
line was probably meant to mean "Logical Operator", and these are
documented in "9.1 Logical Operators" here:
https://www.postgresql.org/docs/14/functions-logical.html
(PostgreSQL docs don't refer to AND/OR etc. as boolean operators)

Perhaps, to make it clear, the change for the example compound expression
could simply be:

+ * - (Var Op Const) AND/OR (Var Op Const)

or at least say something like " - where boolop is AND/OR".

Regards,
Greg Nancarrow
Fujitsu Australia