0008-Fix-RPR-documentation-correct-depth-limit-and-EXPLAI.txt

From 5b47d3a2a88f7a62f5a4c6662c4a1b8e03e5348e Mon Sep 17 00:00:00 2001
From: Henson Choi <assam258@gmail.com>
Date: Sat, 14 Feb 2026 23:56:15 +0900
Subject: [PATCH 8/8] Fix RPR documentation: correct depth limit and EXPLAIN
 marker examples

---
 doc/src/sgml/advanced.sgml   | 9 +++++----
 doc/src/sgml/ref/select.sgml | 2 +-
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 241c7e03a5a..a76fb263a94 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -647,7 +647,7 @@ FROM stock
     and simplifying nested quantifiers
     (e.g., <literal>(A*)*</literal> becomes <literal>A*</literal>).
     These optimizations reduce pattern complexity and also decrease
-    nesting depth, making the 255-level depth limit rarely encountered.
+    nesting depth, making the 253-level depth limit rarely encountered.
     They are applied transparently and can be observed
     in <command>EXPLAIN</command> output.
    </para>
@@ -667,9 +667,10 @@ FROM stock
     markers that indicate optimization opportunities. A double quote
     <literal>"</literal> marks where pattern absorption can occur,
     and a single quote <literal>'</literal> marks absorbable elements
-    within a branch. For example, <literal>A+"</literal> indicates that
-    repeated matches of A can be absorbed, while <literal>(A' B')+"</literal>
-    shows that both A and B within the group are absorbable.
+    within a branch. For example, <literal>a+"</literal> indicates that
+    repeated matches of <literal>a</literal> can be absorbed, while
+    <literal>(a' b')+"</literal> shows that both <literal>a</literal>
+    and <literal>b</literal> within the group are absorbable.
     These markers are primarily useful for understanding internal
     optimization behavior.
    </para>
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 7ec7760f472..f0676bf6f2c 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -1155,7 +1155,7 @@ DEFINE <replaceable class="parameter">definition_variable_name</replaceable> AS
     used in <literal>PATTERN</literal> clause is 251.
     If this limit is exceeded, an error will be raised.
     Additionally, the maximum nesting depth of pattern groups
-    (parentheses) is 255 levels.
+    (parentheses) is 253 levels.
     However, pattern optimizations such as flattening nested sequences
     and simplifying nested quantifiers may reduce the effective depth,
     so this limit is rarely reached in practice.
-- 
2.50.1 (Apple Git-155)