Large audit trail table causes high db activity – especially when using OEM

On various databases, apparently unrelated we have noticed high activity that seems to be associated with the query below. The quieter the database the more the query stands out.

 

SELECT TO_CHAR(current_timestamp AT TIME ZONE 'GMT', 'YYYY-MM-DD HH24:MI:SS TZD') AS curr_timestamp, COUNT(username) AS failed_count, TO_CHAR(MIN(timestamp), 'yyyy-mm-dd hh24:mi:ss') AS first_occur_time, TO_CHAR(MAX(timestamp), 'yyyy-mm-dd hh24:mi:ss') AS last_occur_time
FROM sys.dba_audit_session
WHERE returncode != 0 AND timestamp >= current_timestamp - TO_DSINTERVAL('0 0:30:00')

oem1

The detail of the audit table is that it contains 73M records (more...)

Cloud agent set to DEBUG causing out of memory errors

The following technical detail was put together by a colleague John Evans and have taken it , with his permission, and wrapped some more detail around it as it seemed to be of real value to anybody who might have upgraded an agent to 12.1.0.4

Following an upgrade of the EM agent from 12.1.0.2 (or 12.1.0.3) to 12.1.0.4 after about 90 days of (more...)

One million blog views reached

This morning I will pass the 1 million mark for hits on this blog. My first post was written in 2008 and I remember being quite pleased with myself when I reached 5000 hits, I never dreamt of getting 1 million.

The post with the most number of hits is https://jhdba.wordpress.com/2009/05/19/purging-statistics-from-the-sysaux-tablespace/

One that I get still comments on now saying how well it explains what the SQL92_SECURITY parameter actually does

https://jhdba.wordpress.com/2009/11/23/what-does-the-sql92_security-parameter-actually-do/

(more...)

Discrepancies in v$parameter default values in 12c

In my last blog about security parameters I mentioned I had found some oddities in the default values for parameters in 12.1.0.2, this is a more in-depth analysis of my findings.

Taking the parameter SEC_RETURN_SERVER_RELEASE_BANNER as an example.

Prior to 12c the default value for this parameter was ‘FALSE’, whereas the documentation for 12c (https://docs.oracle.com/database/121/REFRN/refrn10275.htm) states that the default is ‘TRUE’.

To confirm this, I made a (more...)

Security parameters in 11G and 12C

There are 5 parameters that are all prefixed with ‘sec’ in an 11g and 12c database. Actually that is a lie because one is now deprecated in 12c. They are all, as you might guess related to security. This blog is about changes in the default values and some thoughts about whether or not the default value is appropriate or not.

SEC_CASE_SENSITIVE_LOGON TRUE in 11GR1 , 11GR2, DEPRECATED IN 12C
SEC_MAX_FAILED_LOGIN_ATTEMPTS default 11GR1,11GR2=10, 12c=3
SEC_PROTOCOL_ERROR_FURTHER_ACTION (more...)

Getting sql statements out of a trace file

The focus on this post started off in one direction and ended up in another. Originally I had been running a drop user script which had hung and even when I killed the process I could not drop the users as it gave a “ORA-01940: cannot drop a user that is currently connected” – despite the users having left the company months ago and there being no chance of them actually having connected sessions. My (more...)

Running two oracle installations from the same terminal

Two posts from me on the same day. The other one about Datapatch is about a brand new utility in 12c and is probably new to most people. This post caused mixed reactions when I mentioned it at work last week. Some people laughed at my naivety in not knowing about it, others took the same view as me and were interested to hear about it as it may prove useful one day.

A colleague (more...)

Issue with Datapatch – AKA SQL Patching Tool after cloning a database

There have been a few changes in the way patches are managed and monitored in 12c and whilst looking at this I found a potential problem that might occur when you clone or copy databases around, or even build them from a template file.

Firstly when you apply a PSU and run an opatch lsinventory command you now see a description of the patch rather than just a patch number – here showing that PSU (more...)

opatch lsinventory gives “line 384: [: =: unary operator expected”

I noticed the error message when running lsinventory against a  12.1.0.2 Oracle_Home. As the command worked I didn’t think anymore of it until on the same server against an 11.2.0.1 home I got the same error message.

opatch lsinventory
 tr: extra operand `y'
 Try `tr --help' for more information.
 /app/oracle/product/11.2.0.1/dbhome_1/OPatch/opatch: line 384: [: =: unary operator expected

There is a Mos note which provides a solution (more...)

Changing a database link password

I recently found out  that it is possible to change a database link password without dropping and recreating a database link in its entirety.

To be honest I thought this might have existed forever and I had just never come across it but it actually come out in 11GR2

The ALTER DATABASE LINK statement can be used and you do not need to specify the target service either  – all you need  is to run (more...)