Thursday, April 30, 2015

How to find information about CPUs on a Linux server

On RHEL-based Linux distributions, cat the file /proc/cpuinfo, and you will find detailed information about the server's CPUs, including model name, cache size and vendor.

cat /proc/cpuinfo | grep processor
processor       : 0
processor       : 1
processor       : 2
processor       : 3

Or

 lscpu
Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                4
On-line CPU(s) list:   0-3
Thread(s) per core:    1
Core(s) per socket:    1
Socket(s):             4
NUMA node(s):          1
Vendor ID:             GenuineIntel
CPU family:            6
Model:                 58
Stepping:              0
CPU MHz:               2800.000
BogoMIPS:              5600.00
Hypervisor vendor:     VMware
Virtualization type:   full
L1d cache:             32K
L1i cache:             32K
L2 cache:              256K
L3 cache:              25600K
NUMA node0 CPU(s):     0-3

Wednesday, April 29, 2015

Friday, April 24, 2015

How to select rows from a specific partition


The syntax to use if you want to select directly from a specific partition:

SELECT row1, row2 ... 
FROM       my_partitioned_table
PARTITION (my_partition_name)
WHERE ....;

From a subpartition:
SELECT row1, row2 ... 
FROM       my_partitioned_table
SUBPARTITION (my_subpartition_name)
WHERE ....;

With Oracle 11g interval partitioning, the syntax has changed so that you can reference a date range, rather than a partition name, since the auto generated names won't say anything meaningful about their content:

select row1, row2 ..
from my_partitioned_table
PARTITION FOR (to_date('25-FEB-2015','dd-mon-yyyy')); 

Remember that aliases must be specified after the entire FROM-clause, including the PARTITION-part, like this:
select ee.col1
from my_partitioned_table
partition (SYS_P2447) ee
where ee.col2 = 'string1'
and ee.col3 like '%string2%'
order by ee.col1,col2;

If you place the alias immediately after the table name, you'll get the error:
partition (SYS_P2447)
          *
ERROR at line 3:
ORA-00924: missing BY keyword
upon execution.

Tuesday, April 21, 2015

What do do when Oracle Universal Installer reports missing package pdksh-5.2.14 oracle

On RHEL 6, if you encounter situations where the OUI is complaining about the absence of a package pdksh-5.2.14 oracle, do the following:

1. Change directory to /database/stage/cvu/cv/admin 

2. Backup cvu_config: % cp cvu_config backup_cvu_config

3. Edit cvu_config and change the following line:

CV_ASSUME_DISTID=OEL4

to:

CV_ASSUME_DISTID=OEL6

4. Save the updated cvu_config file
5. Install the 11.2.0.3 or 11.2.0.4 software using /database/runInstaller

% cd /database
% ./runInstaller

When installing a 32-bit client like in my case, the OUI will warn that "all requirements have not been met".
This message can be ignored and you can proceed with the installation.
Source: MOS document ID 1454982.1

How to list the content of a .tar file

tar -tvf yourtarfile.tar

How to check whether a library is compiled to 32-bit or 64-bit code on AIX

Use the nm-utility:
"Displays information about symbols in object files, executable files, and object-file libraries."

In the following case, the Library file is 32-bit, since using the -X64 flag is throwing an exception:
nm -X64 /u01/oracle/product/ora11g_client32/mylib.so

0654-210 /u01/oracle/product/ora11g_client32/mylib.so is not valid in the current object file mode.
        Use the -X option to specify the desired object mode.


while using the -X32 flag will produce output similar to the following (abbreviated):
z00u070:ar3u>nm -X32 /u01/oracle/product/ora11g_client32/mylib.so

                     f           -
../../../../../../../src/bos/usr/ccs/lib/libm/m_tables.c f           -
zstcXAForget         U           -
zstcXAOpen           U           -
zstcXAPrepare        U           -
zstcXARecover        U           -
zstcXARollback       U           -
zstcXAStart          U           -

Note that you can use the OBJECT_MODE environment variable and instead execute
export OBJECT_MODE=64
nm /u01/oracle/product/ora11g_client32/mylib.so


How to check whether a library is compiled to 32-bit or 64-bit code on Linux

On Linux, use objdump:

objdump -f /u01/oracle/product/oracle_client32/mylibdir/mylibfile.so
/u01/oracle/product/oracle_client32/mylibdir/mylibfile.so:     file format elf32-i386
architecture: i386, flags 0x00000150:
HAS_SYMS, DYNAMIC, D_PAGED
start address 0x00000560