Thursday, August 27, 2015

How to solve: error while loading shared libraries: libaio.so.1: cannot open shared object file: No such file or directory

After a fresh install of an Oracle 32-bit client on a 64-bit Linux server, we received the following errors when we tried to use any of the binaries under the $ORACLE_CLIENT_HOME/bin directory:
 error while loading shared libraries: libaio.so.1: cannot open shared object file: No such file or directory

It turned out that only the 64-bit version of libaio was installed:
yum list libaio
Loaded plugins: product-id, rhnplugin, security
This system is receiving updates from RHN Classic or RHN Satellite.
Installed Packages
libaio.x86_64  0.3.107-10.el6  @anaconda-RedHatEnterpriseLinux-201301301459.x86_64/6.4
Available Packages
libaio.i686  0.3.107-10.el6  prod-rhel-x86_64-server-6

Solution is to simply install the missing package (output abbreviated):
su -
yum install libaio.i686

downloading Packages:
libaio-0.3.107-10.el6.i686.rpm                                                                                                                                                                    |  21 kB     00:00
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
  Installing : libaio-0.3.107-10.el6.i686                                                                                                                                                                            1/1
  Verifying  : libaio-0.3.107-10.el6.i686                                                                                                                                                                            1/1

Installed:
  libaio.i686 0:0.3.107-10.el6

Complete!

How to create a symlink in unix

Syntax:
ln -s /path/physical_file symlink

For example
cd $ORACLE_HOME/lib
ln -s /u01/oracle/product/oracle_client32/lib/libclntsh.so.11.1 libclntsh.so
ls -altr libclntsh.so
libclntsh.so -> /u01/oracle/product/oracle_client32/lib/libclntsh.so.11.1

Monday, August 24, 2015

What does the DEFAULT DEGREE on tables actually mean?

The DOP (degree of parallelism) settings on a table has to do with the number of threads per instance for scanning the table (an integer), or DEFAULT.

When a tables DEGREE setting is set to DEFAULT, it means that the DOP) is calculated via the following formula:

For a single instance:
DOP = PARALLEL_THREADS_PER_CPU x CPU_COUNT

For an Oracle RAC configuration:
DOP = PARALLEL_THREADS_PER_CPU x CPU_COUNT x INSTANCE_COUNT

The DOP for a table can be viewed in either of the *_TABLES views.

SELECT DEGREE
FROM   DBA_TABLES
WHERE  TABLE_NAME = 'EMP'
AND    OWNER = 'SCOTT';


DEGREE
------------------
         1

Tuesday, August 11, 2015

How to use cpio on AIX

I recently received a patch from Oracle support, and when unpacking with unzip, the resulting file was in the cpio format. Unpacking this file, in turn, is done like this:

mkdir install
cd install
cpio -idcmv < 9205_aix5l64_release.cpio