Since DB2 can't index BLOB/CLOB, can it index CHAR(N) FOR BIT DATA,
especially for storing GUID primary keys.
(Sorry, I don't use DB2 actually).
especially for storing GUID primary keys.
(Sorry, I don't use DB2 actually).
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Re: Index on CHAR(N) FOR BIT DATA?
Absolutely. Is it truly teh whole LOB you need to index?
One thing you may look into is a generated column.
.... lobheader VARCHAR(100) GENERATED ALWAYS AS (CAST(SUBSTR(cl obcol, 1,
100))
then index the header and search by it.
Cheers
Serge
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Serge Rielau
DB2 SQL Compiler Development
IBM Toronto Lab
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Re: Index on CHAR(N) FOR BIT DATA?
Serge Rielau <srielau@ca.e ye-be-em.com> wrote in message news:<c02sq4$hs 6$1@hanover.tor olab.ibm.com>.. .[color=blue]
> Absolutely. Is it truly teh whole LOB you need to index?
> One thing you may look into is a generated column.
> ... lobheader VARCHAR(100) GENERATED ALWAYS AS (CAST(SUBSTR(cl obcol, 1,
> 100))
> then index the header and search by it.[/color]
Thanks, Serge. I never actually have the need to index (B-tree) a very
long string (hundreds to thousands of bytes). But in this case I want
to index CHAR(16) FOR BIT DATA to store 128-bit GUID. I don't want to
use CHAR and store GUID in base64/hex encoding because that would
waste some space (22-32 bytes instead of just 16).
In Postgres I can already index BYTEA and in SQL Server I can index on
BINARY/VARBINARY.
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Pascal
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Re: Index on CHAR(N) FOR BIT DATA?
No problem then. (VAR)CHAR FOR BIT DATA will do what you need.
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Serge Rielau
DB2 SQL Compiler Development
IBM Toronto Lab
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