Re: Row pattern recognition

Hi Tatsuo,

Attached are 40 incremental patches on top of v46, with all
review-driven follow-ups folded in. The 0001-0031 portion is
unchanged from the previous send (filenames preserved). The new
patches 0032-0040 are the delta + follow-up patches we agreed to
deliver on top of 0031, plus two cosmetic patches that surfaced
during the sweep.

As you suggested, I have not refreshed 0001-0031; the new work
is layered on top so that the existing review state on those
patches stays valid.

Numbering and subjects of 0001-0031 are unchanged. The new
patches are:

- 0032 Fix A1 frame optimization bypass test in
rpr_integration

Per your A1 review. Switches the baseline to row_number()
with an explicit ROWS frame so that the bypass guard is
actually exercised. Block comment reworded in A2/A3 style.

- 0033 Fix imperative voice in check_rpr_nav_expr header
comment

Per your typo note: "Checks for" -> "Check for".

- 0034 Fix passive voice in RPR error messages

Per your style note. Sweep of RPR-touched code paths
(parse_rpr.c, parse_func.c, windowfuncs.c) for the
"is not permitted when ... is used" / "can only be used in"
patterns, rewritten to "cannot use ... with" /
"cannot use ... outside".

- 0035 Use Max()/Min() macros for RPR extremum accumulation

Per your Max() macro suggestion. Sweep of all hand-rolled
"if (x > y) y = x;" sites in createplan.c, nodeWindowAgg.c,
and execRPR.c. No double-evaluation hazards on the call
sites.

- 0036 Reword RPR navigation function synopses

Per your sgml note. "Returns the column value at the row"
-> "Returns value evaluated at the row" (the first argument
can be an arbitrary expression).

- 0037 Replace non-ASCII characters in RPR code and tests

Per your non-ASCII note. Sweep of RPR-touched files;
mostly comments and rpr*.out.

- 0038 Move RPR design notes from execRPR.c to README.rpr

Per the README.rpr split we discussed. Extracts the
design block at the head of execRPR.c into
src/backend/executor/README.rpr (plain text, matching the
executor/README convention). No code changes.

- 0039 Apply pgindent canonicalization to RPR comment blocks

Cosmetic. pgindent sweep across RPR-touched files; labeled
blocks wrapped in /*---------- ... *---------- to preserve
hanging indents. No code changes.

- 0040 Reword RPR navigation function descriptions in
pg_proc.dat

Cosmetic. Aligns the eight RPR navigation descr fields
with the surrounding "fetch the ... row value" pattern used
by lag / lead / first_value / last_value / nth_value.

On the items deferred to post-v47:

- DEFINE volatile prohibition: prepared as a self-contained
follow-up so it can be reviewed independently of v47.

- 0009 nfaVisitedElems representation: per your decision,
kept as-is. Three points behind that:

(1) Size concern. visited is 1 bit per element, a flat
NFA element is 16 bytes -- a fixed 128:1 ratio
(~0.78%). The bitmap is dwarfed by the NFA it
tracks (worst case ~4 KiB next to ~512 KiB), so it
is not a memory hot spot.

(2) Bitmapset misfit. Its invariants ("no trailing zero
word", "empty set = NULL") map the per-advance reset
onto pfree + palloc-on-next-add, which defeats the
in-place / fixed-capacity reuse pattern this code
relies on.

(3) Future variant. A high-water mark approach (track
the min/max touched word index, memset only that
span on reset) preserves the in-place pattern and
shrinks reset cost from O(numElements/64) to
O(span_words). Held as a future optimization
candidate.

- 0007 / B7 (Recursive CTE XXX): tracked as a discussion item
awaiting community input on the standard interpretation.

Regards,
Henson