Re: deparsing utility commands

On Thu, Aug 20, 2015 at 4:28 PM, Shulgin, Oleksandr <
oleksandr(dot)shulgin(at)zalando(dot)de> wrote:

> Which gets deparsed as:
>
> ALTER TABLE cwi_test DROP CONSTRAINT cwi_uniq_idx,
> ADD CONSTRAINT cwi_replaced_pkey PRIMARY KEY
> USING INDEX cwi_replaced_pkey;
>
> The problem is that during constraint transformation, the index is being
> renamed to match the constraint name and at the deparse stage the original
> index name appears to be lost completely... I haven't figure out if
> there's a way around unless we introduce a new field in IndexStmt
> (originalName?) to cover exactly this corner case.
>
> The updated versions of the core-support patch and the contrib modules are
> attached.
>

Another quirk of ALTER TABLE is that due to multi-pass processing in
ATRewriteCatalogs, the same command might be collected a number of times.
For example, in src/test/regress/sql/inherit.sql:

alter table a alter column aa type integer using bit_length(aa);

the "alter column type" then appears 4 times in the deparsed output as
identical subcommands of a single ALTER TABLE command.