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RDBPROD: How to Troubleshoot Performance Problems Involving Access to an Rdb Database via a DBlink (Doc ID 867679.1)

Last updated on SEPTEMBER 20, 2023

Applies to:

Oracle Database - Enterprise Edition - Version and later
Oracle Rdb Server on OpenVMS - Version 7.2 and later
Oracle SQL/Services for Rdb on OpenVMS - Version 7.3 and later
Oracle Database Cloud Schema Service - Version N/A and later
Oracle Database Exadata Express Cloud Service - Version N/A and later
Information in this document applies to any platform.


This guide is intended to explain how to investigate a query that is running slower than expected when that query involves access to an Rdb database via a DBlink.

Troubleshooting Steps

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In this Document
Troubleshooting Steps
 Trace Files
 Is the Problem in Rdb?
 Not Rdb?
 OCI Services Version
 Statistics in the Trace
 TableScan Cost
 Collecting Better Statistics
 Outer Join
 Still Slow

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