Delete or Update Running Slow with 'db file scattered read waits' on Index Range Scan
(Doc ID 296727.1)
Last updated on MARCH 03, 2022
Applies to:
Oracle Database - Enterprise Edition - Version 9.2.0.6 and laterOracle Database Exadata Cloud Machine - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Oracle Database Exadata Express Cloud Service - Version N/A and later
Oracle Database Cloud Exadata Service - Version N/A and later
Information in this document applies to any platform.
Symptoms
- SQL is running slow, and the 10046 event trace shows wait on "db file scattered read" and "db file scattered read" is on an index.
- The execution plan indicates the table is getting accessed by "index range scan", and there is no indication of full scan on either on the table or the index. The waits on the index range scan on the index should be shown an "db file sequential reads"
- The number of blocks fetched during "db file scattered read" is 11 which is different than the db_file_multiblock_read_count parameter
Cause
To view full details, sign in with your My Oracle Support account. |
|
Don't have a My Oracle Support account? Click to get started! |