Re: [PERFORM] EXTERNAL storage and substring on long strings - Mailing list pgsql-sql

From Tom Lane
Subject Re: [PERFORM] EXTERNAL storage and substring on long strings
Date
Msg-id 6311.1060884021@sss.pgh.pa.us
Whole thread Raw
In response to Re: [PERFORM] EXTERNAL storage and substring on long strings  (Jan Wieck <JanWieck@Yahoo.com>)
Responses Re: [PERFORM] EXTERNAL storage and substring on long strings  (Scott Cain <cain@cshl.org>)
Re: [PERFORM] EXTERNAL storage and substring on long strings  (Jan Wieck <JanWieck@Yahoo.com>)
List pgsql-sql
Jan Wieck <JanWieck@Yahoo.com> writes:
> Doesn't look that unrealistic to me. A plain text based substring
> function will reassemble the whole beast first before cutting out the
> wanted part. His manually chunked version will read only those chunks
> needed.

So does substr(), if applied to EXTERNAL (non-compressed) toasted text.
See John Gray's improvements a release or two back.

            regards, tom lane

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