btree.sgml typo?
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
Attachments:
btree.difftext/x-patch; charset=us-asciiDownload
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
On Sat, Jan 5, 2019 at 1:35 AM Tatsuo Ishii <ishii@sraoss.co.jp> wrote:
<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.
+1 for applying this patch. The existing wording is highly confusing,
especially because many people already incorrectly think that a B-Tree
is just like a self-balancing binary search tree.
There is no consensus on exactly what the "b" actually stands for, but
it's definitely not "binary". I suppose that the original author meant
that a B-Tree is a generalization of a binary tree, which is basically
true -- though that's a very academic point.
--
Peter Geoghegan
On Sat, Jan 5, 2019 at 1:35 AM Tatsuo Ishii <ishii@sraoss.co.jp> wrote:
<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.+1 for applying this patch. The existing wording is highly confusing,
especially because many people already incorrectly think that a B-Tree
is just like a self-balancing binary search tree.There is no consensus on exactly what the "b" actually stands for, but
it's definitely not "binary". I suppose that the original author meant
that a B-Tree is a generalization of a binary tree, which is basically
true -- though that's a very academic point.
Any objection for this? If not, I will commit the patch to master and
REL_11_STABLE branches (btree.sgml first appeared in PostgreSQL 11).
Best regards,
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese:http://www.sraoss.co.jp
On Sat, Jan 5, 2019 at 1:35 AM Tatsuo Ishii <ishii@sraoss.co.jp> wrote:
<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.+1 for applying this patch. The existing wording is highly confusing,
especially because many people already incorrectly think that a B-Tree
is just like a self-balancing binary search tree.There is no consensus on exactly what the "b" actually stands for, but
it's definitely not "binary". I suppose that the original author meant
that a B-Tree is a generalization of a binary tree, which is basically
true -- though that's a very academic point.Any objection for this? If not, I will commit the patch to master and
REL_11_STABLE branches (btree.sgml first appeared in PostgreSQL 11).
Done.
Best regards,
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese:http://www.sraoss.co.jp