Oracle removed the password from the DBA_USERS view in 11g, but apparently it can be fetched from the USER$ table (to which no one should normally have access) by concatenating SPARE4 and the PASSWORD column with a semicolon between the…
Category: Oracle
Printing Oracle silent installer prerequisite failed checks
I use what is below to print out prerequisites that aren’t met when performing a silent install. It is a lot easier to read, and prints only those components that have a failed check. #!/bin/awk -f { if ($0 ==…
ACFS install on CentOS
I run CentOS on a test cluster, and every time I patch it with a PSU or whatever, my ACFS installation is trashed as CentOS is not officially supported. To fix this, change the following section in $GRID_HOME/lib/osds_acfslib.pm… if ((defined($release))…
ORA-12516 – Possible causes
At least one is when your processes parameter in the database instance(s) has/have been exceeded. java.sql.SQLException: Listener refused the connection with the following error: ORA-12516, TNS:listener could not find available handler with matching protocol stack at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:451) at oracle.jdbc.driver.PhysicalConnection.(PhysicalConnection.java:535) at…
Instance state values in crsctl
As far as I can tell, the following values represent possible values for the state of instance as reported by crsctl status resource -t expressdb1:oracle:ecomm1:/u01/app/11.2.0/grid/bin# strings -a crsctl.bin | sed -n “16887,16910 p” Not Supported Any State Abnormal Termination Instance…
SQL Patch
Oracle comes up with some cool tricks for fixing poorly performing SQL, especially code to which you have no direct access. If you absolutely know a given hint will always work, the Oracle optimizer blog recently posted a method for…
Reverse engineering a SQL replay script from a 10046 trace file
This will be the coup de grâce (but in a good way:)) if I can ever finish it. I have wanted to do this for years, and keep getting closer. Search for awk 10046 in the search bar on this…
Printing execution times with associated bind variables
In a previous post, we showed how you can extract the count of executions of a given SQL statement for a given bind variable. We recently found a need to print each execution a given SQL statement with the bind…
Change the mount point for an ACFS filesystem
Changing the mount point for an ACFS filesystem is not a straightforward process, and is not a well documented process. We found ourselves in this position after we misspelled the goldengate directory we wanted to use for the binaries and…
Linux firewall rules for RAC
Most notes on the Oracle MOS support site suggest disabling the firewall supplied in most Linux distros as managed by the iptables program. I think this is a bit drastic, and results in lazy thinking at best, and an exposed…