Using MySQL Meta Data Effectively at ODTUG Kaleidoscope 2010

Since Oracle owns MySQL through its acquisition of Sun, more Oracle conferences are providing MySQL content. This past Oracle Development Tools User Group (ODTUG) Kaleidoscope 2010 conference from June 27 through July 1 had a whole dedicated track for MySQL.

Using MySQL Meta Data Effectively - title slide thumbnail

I was fortunate enough to have the opportunity to speak on MySQL metadata, titled “Using MySQL Meta Data Effectively“. Here’s the abstract:

This presentation discusses what MySQL meta data is available including the ‘mysql’ meta schema, the INFORMATION_SCHEMA (I_S) tables first introduced in MySQL 5.0 and extended in MySQL 5.1, storage engine specific INFORMATION_SCHEMA tables, as well as techniques for writing your own INFORMATION_SCHEMA plug-ins. MySQL also provides a number of SHOW commands that provide easily formatted presentation of MySQL meta data. Dossy Shiobara will also discuss some of the limitations and performance implications of the INFORMATION_SCHEMA.

Paper first page thumbnail

You can download the materials from my session here:

Installing Oracle 11g R2 on Solaris 10 with EMC PowerPath

For anyone who has the misfortune of having to install a multi-node RAC cluster of Oracle 11g R2 on Solaris 10 (in my case, SPARC 64-bit) with an EMC PowerPath, hopefully these notes I’ve collected will come in useful. I certainly suffered plenty trying to get this install to work and web searches didn’t turn up very many useful results at the time.

Make sure you set tunable limits correctly.

Previously, you would edit /etc/system to change tunable parameters then reboot the system, but starting in Solaris 10, there’s a new “projects” system where tunables can be configured. For my installation, the cluster nodes had 16GB of RAM each, so I used these settings (as root):

$ projmod -U oracle -sK "process.max-file-descriptor=(priv,4096,deny)"
$ projmod -U oracle -sK "project.max-msg-ids=(priv,256,deny)"
$ projmod -U oracle -sK "project.max-sem-ids=(priv,256,deny)"
$ projmod -U oracle -sK "project.max-shm-ids=(priv,256,deny)"
$ projmod -U oracle -sK "project.max-shm-memory=(priv,16GB,deny)"

You can check these settings by inspecting /etc/project and looking for the entry.

Also, when running in a RAC configuration, some Oracle processes like crsd run as root, so these will be necessary as well:

$ projmod -sK "project.max-shm-ids=(priv,256,deny)" system
$ projmod -sK "project.max-shm-memory=(priv,16GB,deny)" system

This appears to be a catch-all way of ensuring these settings are in use for all users:

$ projmod -sK "project.max-shm-ids=(priv,256,deny)" default
$ projmod -sK "project.max-shm-memory=(priv,16GB,deny)" default

Failing to set these settings for system and default seems to result in Oracle “ORA-01102: cannot mount database in EXCLUSIVE mode” errors when trying to start a database instance.

NB: There may be circumstances when you still need to configure these tunables in /etc/system. For more information, see Oracle Metalink 435464.1 ENABLING SOLARIS PROJECT SETTINGS FOR CRS.

Failure to create the DATA diskgroup using ASM

I wasted a good 6 hours trying to understand why I kept getting the following error during the 11g R2 grid package install:

ORA-15020: discovered duplicate ASM disk "DATA_0000"

Turns out, I had only set the permissions on /dev/rdsk/emcpower* correctly on one of the nodes in the cluster. The permissions need to be correct on all nodes in the cluster, as the installer operates on all cluster nodes as part of the install – duh! Beware of this gotcha, it can be very frustrating.

WARNING: oradism did not start up correctly.

In diag/rdbms/*/$ORACLE_SID/trace, in the alert_${ORACLE_SID}.log, you may find this message:

WARNING: oradism did not start up correctly.
  Dynamic ISM can not be locked.
oradism creation failed for unknown reasons 0 8 105

This is apparently a bug described in Oracle Metalink 374367.1. By default, the Oracle installer installs the file with ownership oracle:oinstall and mode 0750. It needs to be suid root, sgid dba. The solution is to perform the following steps (as root):

$ cd $ORACLE_HOME/bin
$ chown root:dba oradism
$ chmod 6550 oradism

Then, restart the database.

Back up the Enterprise Manager encryption key!

The Enterprise Manager runs on port 1158, using HTTPS. The encryption key is located here:


Back this key up, because without it, the Enterprise Manager data can’t be accessed.

ERROR: NMO not setuid-root (Unix-only)

When using Enterprise Manager, you might get the following error message:

ERROR: NMO not setuid-root (Unix-only)

This occurs because the NMO binaries need to be setuid-root, as the error explains. Use these steps to correct the problem:

$ cd $ORACLE_HOME/bin
$ chown root nmb nmhs nmo
$ chmod 6750 nmb nmhs nmo

Have you installed a multi-node RAC cluster using Oracle 11g R2 on Solaris 10? Did you discover any gotchas that prevented a successful installation “out of the box”? Please, share them in the comments below so that others can benefit from our pain!