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  1. Doc: fix meaning of acronym "btree".

  1. btree.sgml typo?

    Tatsuo Ishii <ishii@sraoss.co.jp> — 2019-01-05T09:35:32Z

    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

  2. Re: btree.sgml typo?

    Peter Geoghegan <pg@bowt.ie> — 2019-01-05T17:41:37Z

    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

  3. Re: btree.sgml typo?

    Tatsuo Ishii <ishii@sraoss.co.jp> — 2019-01-07T05:10:42Z

    > 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

  4. Re: btree.sgml typo?

    Tatsuo Ishii <ishii@sraoss.co.jp> — 2019-01-08T01:00:14Z

    >> 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