Tag: AWR

How to retrieve growth history for oracle tablespaces

A customer recently asked us to identify tablespaces that most contributed to sudden space consumption on ASM. It’s easy enough to find what’s using the most space, but finding what’s been growing is a little less straightforward. Fortunately, Oracle keeps…

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Creating Ansible Custom Module for AWR report generation

Creating AWR reports is a common task for many DBAs. At times, you may need to generate multiple AWR reports from multiple databases for performance audit; Ansible allows you to automate these types of tasks. You can, for example, generate…

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Enqueue bytes – is that a pun?

Jared Still explains how to troubleshoot enqueue locking events in Oracle databases.

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Pro-active AWR Data Mining to find change in SQL Execution Plan

Many times we have been called for the poor performance of a database and it has been narrowed down to a  SQL statement. Subsequent analysis have shown that the execution plan has been changed and a wrong execution plan was being…

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Do AWR Reports Show the Whole Picture?

AWR report is a great source of aggregated information on top activities happening in our databases. I use data collected in AWR quite often, and obviously the easiest way of getting the data out from the AWR is by running the…

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Do you have enough Redo?

The question of whether a database has enough redo logs available is quite common. The documentation suggests to use FAST_START_MTTR_TARGET and V$INSTANCE_RECOVERY.OPTIMAL_LOGFILE_SIZE to identify “the optimal” redo log size based on the target recovery time. I’ve never used it and…

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Meaning of “Disk Reads” Values in DBA_HIST_SQLSTAT

This post relates to my previous writing on mining the AWR. I noticed that it’s very easy to misinterpret the DISK_READS_TOTAL and DISK_READS_DELTA columns in DBA_HIST_SQLSTAT. Let’s see what the documentation says: DISK_READS_TOTAL – Cumulative number of disk reads for…

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Trying Out S-ASH: Historical Performance Data for the Under-Licensed

I was recently playing with an Oracle XE database. The main benefit of Oracle XE is that it can be used free of charge.

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