RE: INDEX

["Shaw, David" <dshaw@xxxxxxxxxxx>]

Ajay,

Answer to Q1) Logical files use a binary radix index, the same as SQL CREATE
INDEX.

Answer to Q2) Encoded vector indexes (EVI's) are ONLY used by the query
optimizer when selecting records.  They can't be used for reading records,
either sequentially (RPG READ, READP, or primary file implicit) or randomly
(RPG CHAIN, SETLL, SETGT, READE, READPE).  As I understand it, EVI's work
best when you're building an index over a single field that has a limited
number of values, which is then used for record selection in an SQL WHERE
clause or equivalent (Query/400, OPNQRYF, ODBC, etc.).

Dave Shaw
Spartan International, Inc.
Spartanburg, SC

-----Original Message-----
From: AKumar@rccl.com [mailto:AKumar@rccl.com]
Sent: Friday, July 14, 2000 9:41 AM
To: RPG400-L@midrange.com
Subject: INDEX


Hi,
     I am trying to use different indexes in stored procedure to maximize
the performance .
There are three choices of creating index.
CASE I) Create logical file.
CASE 2) CREATE INDEX ..........
CASE 3) CREATE ENCODED VECTOR INDEX..........

Q 1) What kind of index is created when we create Logical File?
Q 2) If there is some thumb rule (or rule) which I need to follow during
going for a index?

It is very important for us.

Regards,
Ajay Kumar
305-539-6621.



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