Re: SQL Tuning Question

Hi Karl,

thanks for the suggestion but the note field is varchar2(2000). Since the db block size is 4k, I cannot create an index on any field larger than about 1500 characters. The Create Index statement fails with: ORA-01450: maximum key length (1578) exceeded

Thanks,
Roy

In article <06da2e58.ac5cbb4b_at_usw-ex0105-034.remarq.com>,   Karl R. <kreitsch_at_zdnetonebox.com> wrote:
> Hello Roy
>
> Try to us an bitmap-index on this column
>
> Bitmapindexes includes NULL-Valued-Columns too
>
> In Server -Concepts for 8i you can read in Chapter Schema-
> objects 10-35 you can read :
>
> Bitmap Indexes and Nulls
> Bitmap indexes include rows that have NULL values, unlike most
> other types of
> indexes. Indexing of nulls can be useful for some types of SQL
> statements, such as
> queries with the aggregate function COUNT.
>
> Importent is that the table is not heavy accessed with updates
> on the index column because bitmapped-indexes are locking many
> rows due to their design!
>
> A Buffer Cache Hit Rate with 50% is amazing, there seems to be
> some gfull-tablecans ond different tables.
>
> Regards
> /Karl
>
> Karl Reitschuster
> Senior Consultant CSC Ploenzke AG
> Oracle Databases, Implementation, Performance-Tuning
> <!Jesus is Lord!>
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Before you buy. Received on Fri May 12 2000 - 00:00:00 CDT