Re: SQL performance on index?

From: Frank Langelage <frank_at_lafr.de>
Date: Thu, 15 Jun 2006 20:31:33 +0200
Message-ID: <4fdnc5F1hd3gtU1@individual.net>

James Yang wrote:
> Mih 写道：
>

>> Make the index on arbid, mandt,  "AUFPL" , "OBJNR" , "APLFL".
>> This way you will have to scan index with 5 fileds vs. scanning table
>> with 20+ fields.
>> The index should be b-tree, because is the combination of 5 fileds is
>> changing too much for a bitmap index.

>
>
> Yes, this is what I want. Let the sql just access the index, not a full
> table scan.
>
> Another question: the first field of the index should be in where
> clause, so it can be ARBID or MANDT, right?
>

The 1st field in the index *must* be the field with the most distinct values from the where clause -> ARBID.
Then the rest of the where clause fields: MANDT. Then the fields selected: AUFPL, OBJNR, APLFL. The order of this fields is irrelevant. Received on Thu Jun 15 2006 - 13:31:33 CDT