There is a sentence in btree.sgml: <productname>PostgreSQL</productname> includes an implementation of the standard <acronym>btree</acronym> (multi-way binary tree) index data structure.
I think the term "btree" here means "multi-way balanced tree", rather than "multi-way binary tree". In fact in our btree, there could be more than one key in a node. Patch attached. Best regards, -- Tatsuo Ishii SRA OSS, Inc. Japan English: http://www.sraoss.co.jp/index_en.php Japanese:http://www.sraoss.co.jp
diff --git a/doc/src/sgml/btree.sgml b/doc/src/sgml/btree.sgml index c16825e2ea..996932e35d 100644 --- a/doc/src/sgml/btree.sgml +++ b/doc/src/sgml/btree.sgml @@ -13,7 +13,7 @@ <para> <productname>PostgreSQL</productname> includes an implementation of the - standard <acronym>btree</acronym> (multi-way binary tree) index data + standard <acronym>btree</acronym> (multi-way balanced tree) index data structure. Any data type that can be sorted into a well-defined linear order can be indexed by a btree index. The only limitation is that an index entry cannot exceed approximately one-third of a page (after TOAST