Index - Sequential Read

[Former Member]

Dear friends,

In one of our client oracle is used as SAP DB.

Here the major problem is, even though the reports made use of primary and secondary indexs, they are going to sequential read instead of direct read and the performance is badly affected.

Kindly suggest.

Praveen Lobo

[Former Member]

"Sequential read" in SM50 / SM66 only indicates that potentially more than 1 record is returned (while "direct read" always returns a maximum of 1 record). As a consequence every non-unique index access is necessarily a "sequential read" (because more than 1 record can be returned). See note 825653 (15) for additional information.

[markus_doehr2]

Here the major problem is, even though the reports made use of primary and secondary indexs, they are going to sequential read instead of direct read and the performance is badly affected.

First: don´t rely on information on SM50/SM66.

Second: did you do an SQL trace in ST05 for the statement and see what execution plan is used?

Markus

[Former Member]

Dear Markus,

When i check in ST05, indexes are properly used (in Explain button). But when i check in SM50 during execution all sql statements are read sequentially (even though indexes are used in the statements).

Kindly suggest.

Praveen Lobo

[markus_doehr2]

Please read 825653 - Oracle: Common errors, point 15.

Markus