Re: [HACKERS] varchar() vs char16 performance

Tatsuo Ishii <t-ishii@sra.co.jp>

From: t-ishii@sra.co.jp
To: "Thomas G. Lockhart" <lockhart@alumni.caltech.edu>
Cc: Postgres Hackers List <hackers@postgreSQL.org>
Date: 1998-03-16T06:20:36Z
Lists: pgsql-hackers
>I ran some timing tests to check the performance of varchar() vs char16.
>The results of the test indicate that there is no difference in
>performance (within the timing scatter of the tests):
>
>char16	vc(16)
> 0.99s	 1.05s	1 row (this measures startup time, not types)
>39.29s	39.28s	~65000 rows
>
>The char2,4,8,16 types seem to have no value-added over the
>better-supported char(), varchar(), text types; I am considering
>removing them from the backend, and instead have the parser
>transparently translate the types into varchar() (or char() - I'm not
>certain which is a better match for the types) for v6.4. Applications
>would not have to be changed.
>
>Comments?

Please do not remove char2! Some users uses it for making an array of
char.

create table c(c char2[]);

Seems strange? Yes. Actually what he wanted to do was:

test=> create table c(c char[]);
ERROR:  parser: parse error at or near "["
--
Tatsuo Ishii
t-ishii@sra.co.jp