Tip for the Future: Segmentation fault because of LD_LIBRARY_PATH

More than once I forgot to set LD_LIBRARY_PATH in new environments and sometimes I faced awkward errors. The most common is “Segmentation Fault”.
Today a lost almost 15 minutes searching about Segmentation Fault related to Datapump on 11.2, then I realized I forgot the LD_LIBRARY_PATH again…

Other day, in a Upgrade from 11.2.0.3.6 to 11.2.0.4.2 I get stuck in lots of errors on upgrade process. Bullshit again, after a few minutes of errors and searching I founded a post, somewhere, talking about the variables setting.

So, Matheus from the Future: Check if LB_LIBRARY_PATH and other variables are setted for the right Oracle Home.

I expect this post save me from this same pain in the future. 😛
Thanks.

Matheus.

Optimize fragmented tables in MySQL

It happens on MySQL, as you know. Run an Optimize Table solve the question.
BUT, be careful! During the optimize the table stay locked (writing is not possible).

Fragmentation-table
(Fragmented Table)

So what?
To not cause a lock in every table, the script below shows and runs (if you want to list but not run, comment the line) only for tables that have fragmentation.

It was very useful to me! 🙂

#!/bin/sh
echo -n "MySQL username: " ; read username
echo -n "MySQL password: " ; stty -echo ; read password ; stty echo ; echo
mysql -u $username -p"$password" -NBe "SHOW DATABASES;" | grep -v 'lost+found' | while read database ; do
mysql -u $username -p"$password" -NBe "SHOW TABLE STATUS;" $database | while read name engine version rowformat rows avgrowlength datalength maxdatalength indexlength datafree autoincrement createtime updatetime checktime collation checksum createoptions comment ; do
if [ "$datafree" -gt 0 ] ; then
fragmentation=$(($datafree * 100 / $datalength))
echo "$database.$name is $fragmentation% fragmented."
mysql -u "$username" -p"$password" -NBe "OPTIMIZE TABLE $name;" "$database"
fi
done
done

The resul will be like:

MySQL username: root
MySQL password:
...
mysql.db is 12% fragmented.
mysql.db optimize status OK
mysql.user is 9% fragmented.
mysql.db optimize status OK
...

This script is a full copy from this post by Robert de Bock.
Thanks, Robert!

Matheus.

100th Post!

Just to keep on track: This is the 100th post!

It has been a great pleasure to be sharing and learning with you all along.
Thanks to all followers, readers and collaborators!

100 anniversary

Explain ORA-XXX on SQL*Plus

For those when the error is unkown/rare, SQL*Plus helps us. It’s just call “oerr” from OS.

See the Linux example (made on RHEL):

SQL>  !oerr ora 01652
01652, 00000, "unable to extend temp segment by %s in tablespace %s"
// *Cause:  Failed to allocate an extent of the required number of blocks for
//          a temporary segment in the tablespace indicated.
// *Action: Use ALTER TABLESPACE ADD DATAFILE statement to add one or more
//          files to the tablespace indicated.

Pretty cool, han?

Have a nice week!
Matheus.

PRCR-1079 CRS-2674 CRS-5017 ORA-27102: out of memory Linux-x86_64 Error: 28: No space left on device

# Problem

myserver:/home/oracle>srvctl start database -d mydb
PRCR-1079 : Failed to start resource ora.mydb.db
CRS-5017: The resource action "ora.mydb.db start" encountered the following error:
ORA-27102: out of memory
Linux-x86_64 Error: 28: No space left on device
. For details refer to "(:CLSN00107:)" in "/grid/product/11.2.0/log/myserver/agent/crsd/oraagent_oracle/oraagent_oracle.log".
CRS-2674: Start of 'ora.mydb.db' on 'myserver' failed
CRS-5017: The resource action "ora.mydb.db start" encountered the following error:
ORA-27102: out of memory
Linux-x86_64 Error: 28: No space left on device
. For details refer to "(:CLSN00107:)" in "/grid/product/11.2.0/log/myserver2/agent/crsd/oraagent_oracle/oraagent_oracle.log".
CRS-2674: Start of 'ora.mydb.db' on 'myserver2' failed
CRS-2632: There are no more servers to try to place resource 'ora.mydb.db' on that would satisfy its placement policy
myserver:/home/oracle>

# Solution

On /etc/sysctl.conf ajust as below and then reload sysctl (“sysctl -p” as root):

#Old
#kernel.shmall = 24641536
#New
kernel.shmall = 4294967296

Matheus.

Shellscript: Master Blaster KB!

Hi all!
I frequently have to search about shellscript syntax (things like conditions and comparatives).

Shellscripting is not a daily routine, but sometimes it’s needed and I never remmember from the last time…

For those kind of people, this link/book shall be very helpful 🙂

(it’s in portguese, but everyone will understand…)
http://aurelio.net/shell/canivete/

Thanks for this tools, Aurelio!

Have a nice week guys!