Hi!

On Thu, Sep 3, 2026 at 6:38 AM Michael Paquier <[email protected]> wrote:
> Sami has also mentioned to me off-list that we may want something
> smarter in terms of the management of the DefElems that include
> strings, because we have other commands with contents that we may want
> to normalize in some contexts, like an ALTER TABLE with a password as
> one example.  Perhaps it would be better to not rush that part.

Agreed, so v3 attached drops the generic part and does WAIT only.

Two things today: waits differing only in the timeout get an entry
each, and so does the same wait with its options written in another
order.

  1 | WAIT FOR LSN $1 WITH (mode 'primary_flush', timeout '5ms')
  1 | WAIT FOR LSN $1 WITH (mode 'primary_flush', timeout '7ms')
  1 | WAIT FOR LSN $1 WITH (timeout '5ms', mode 'primary_flush')

With v3 those are one entry:

  3 | WAIT FOR LSN $1 WITH (mode 'primary_flush', timeout $2)

while the modes stay apart, as Sirisha asked for:

  1 | WAIT FOR LSN $1 WITH (mode 'standby_replay', timeout $2, no_throw)
  1 | WAIT FOR LSN $1 WITH (mode 'standby_write', timeout $2, no_throw)

WaitStmt.options gets a custom jumble function that walks the
recognized options in a fixed order instead of the order written,
records TIMEOUT as a constant, and jumbles MODE and NO_THROW as given.
No generic DefElem option normalization: what a value means differs
per option and only the command knows, which is the same problem
VariableSetStmt.jumble_args solves per grammar flavor.

DefElem gains arg_location, since DefElem.location points at the
option name -- recording that one normalizes the wrong token:

  WAIT FOR LSN $1 WITH (mode 'primary_flush', $2 '5ms')

and the argument node is a bare String or Integer, which carries no
location at all.  Nothing else reads the new field, so no other
statement changes.

One wart left alone: "WITH (no_throw)" and "WITH (no_throw true)" are
still separate entries, as VACUUM (ANALYZE) and VACUUM (ANALYZE true)
are today.  Resolving it would mean calling defGetBoolean() while
jumbling, which can throw.

Passwords in pg_stat_statements are untouched by this and can go to
their own thread.

------
Regards,
Alexander Korotkov
Supabase

Attachment: v3-0001-Jumble-the-WAIT-option-list-by-meaning-not-by-spe.patch
Description: Binary data

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