| From: | Jan Wieck <JanWieck(at)Yahoo(dot)com> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | Scott Cain <cain(at)cshl(dot)org>, PgSQL Performance ML <pgsql-performance(at)postgresql(dot)org>, pgsql-sql(at)postgresql(dot)org |
| Subject: | Re: [SQL] EXTERNAL storage and substring on long strings |
| Date: | 2003-08-14 18:55:38 |
| Message-ID: | 3F3BDB2A.40506@Yahoo.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-performance pgsql-sql |
Tom Lane wrote:
> Jan Wieck <JanWieck(at)Yahoo(dot)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.
Duh ... of course, EXTERNAL is uncompressed ... where do I have my head?
Jan
--
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