Re: Reducing the overhead of NUMERIC data - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Reducing the overhead of NUMERIC data
Date
Msg-id 8698.1131070663@sss.pgh.pa.us
Whole thread Raw
In response to Re: Reducing the overhead of NUMERIC data  (Gregory Maxwell <gmaxwell@gmail.com>)
Responses Re: Reducing the overhead of NUMERIC data
List pgsql-hackers
Gregory Maxwell <gmaxwell@gmail.com> writes:
> Another way to look at this is in the context of compression: With
> unicode, characters are really 32bit values... But only a small range
> of these values is common.  So we store and work with them in a
> compressed format, UTF-8.

> As such it might be more interesting to ask some other questions like:
> are we using the best compression algorithm for the application, and,
> why do we sometimes stack two compression algorithms?

Actually, the real reason we use UTF-8 and not any of the
sorta-fixed-size representations of Unicode is that the backend is by
and large an ASCII, null-terminated-string engine.  *All* of the
supported backend encodings are ASCII-superset codes.  Making
everything null-safe in order to allow use of UCS2 or UCS4 would be
a huge amount of work, and the benefit is at best questionable.
        regards, tom lane


pgsql-hackers by date:

Previous
From: Tom Lane
Date:
Subject: Re: slru.c race condition (was Re: TRAP: FailedAssertion("!((itemid)->lp_flags
Next
From: Cedric Berger
Date:
Subject: postgresql-8.1RC1 on Solaris 10, amd64x2