Friday, October 7, 2016

Explore Oracle Database In-Memory in 12C – Part2

Hi Everyone,

It’s been couple of months that I published my last article. Finally I was able to find some time and published new article in Oracle Experts website media "Allthingsoracle.com" by RedGate

In this article I will cover:

·         Multitenant Architecture compatibility
·         In-Memory Column store in RAC
·         How to manage In-Memory Tables
·         IM Column store Compression Methods
·         How to manage the In-Memory Column
·         Oracle Compression Advisor
·         How to manage In-Memory Tablespace

Please view the article using below link.
Explore Oracle DatabaseIn-Memory – Part2

This article will help users to understand In-Memory architecture, benefits, restrictions, functionality, performance…etc.

I hope you like the article and it will be helpful to you.

Please leave your valuable comments.

Regards,
Satishbabu Gunukula, Oracle ACE
http://www.oracleracexpert.com

mopatch.sh: line 5682: dc: command not found


While applying SBP patch on ORACLE_HOME come across an issue an error and mopatch failed.

I see below error in log file.

executing: "/oracle/ORAX/product/11204/bin/unzip" -qq -d "./mopatch-wmOvOg" "SAP11204P_1411-20010781.ZIP" "SBP_112044_201411/19493764/*"
/oracle/ORAX/product/11204/MOPatch/mopatch.sh: line 5682: dc: command not found
Processing patch "SAP11204P_1411-20010781.ZIP!19493764!19493764"...failed.
Reason: Cannot calculate "" as (447392 > 7914856) ? 1 : 0.
Processing patch "SAP11204P_1411-20010781.ZIP!19493764!17478514"...(1 of 7)
Processing patch "SAP11204P_1411-20010781.ZIP!19493764!17478514"...failed.
Reason: Cannot calculate "" as (447392 > 7914508) ? 1 : 0.


I did some research on error “Reason: Cannot calculate” but didn’t find much in google or oracle support site. When I look into the error closely I see that “dc” command not found.

After investigation on "dc: command" I found that user will get this error if RPM missing at OS level. After installing “ bc-1.06.95-1.el6.x86_64” rpm the SBP patch went fine without any issue.

Regards
Satishbabu Gunukula, Oracle ACE
http://www.oracleracexpert.com

Thursday, September 29, 2016

How to recreate oraInventory using Oracle Universal Installer (OUI)

I come across the missing oraInventory issue and I have recreated the inventory using Oracle Universal installer. In case inventory got corrupted, you can use the same steps.

1. Make sure you set the ORACLE_HOME variable
$ export ORACLE_HOME=/oracle/product/11203

2. Update the $ORACLE_HOME/oraInst.loc file to point to the inventory or wherever you want to keep the inventory.

Forex:- cat $ORACLE_HOME/oraInst.loc
inventory_loc=/oracle/oraInventory
inst_group=dba


3. Run below OUI command to register ORACLE_HOME

$cd $ORACLE_HOME/oui/bin
$ ./runInstaller -silent -invPtrLoc $ORACLE_HOME/oraInst.loc -attachHome ORACLE_HOME="/oracle/product/11203" ORACLE_HOME_NAME="OraDb11g_home1"


In case of RAC environment, pls use below syntax

$./runInstaller -silent -attachHome oracle_home="<oracle_home_location>"
"cluster_nodes={<node1, node2>}" local_node="<node_name>"


4. You can verify the inventory created or not using below command
$ORACLE_HOME/OPatch/opatch lsinventory -invPtrLoc $ORACLE_HOME/oraInst.loc

Deleting Oracle Home from Central Inventory
$./runInstaller -silent -detachHome -invPtrLoc $ORACLE_HOME/oraInst.loc 
ORACLE_HOME="<Oracle_Home_Location>"

Regards
Satishbabu Gunukula, Oracle ACE

Thursday, September 22, 2016

Explore Oracle Database In-Memory in 12C – Part1

Hi Everyone,

It’s been couple of months that I published my last article. Finally I was able to find some time and published new article in Oracle Experts website media "Allthingsoracle.com" by RedGate

In this article I will cover:

·         Oracle In-Memory Dual-Format Architecture
·         In-Memory Column Store
·         In-Memory Column Store Restrictions
·         How to enable In-Memory Column Store

Please view the article using below link.
Explore Oracle Database In-Memory – Part1

You will see more articles on this topic in near future.

This article will help users to understand In-Memory architecture, benefits, restrictions, functionality, performance…etc.

I hope you like the article and it will be helpful to you.

Please leave your valuable comments.

Regards,
Satishbabu Gunukula, Oracle ACE
http://www.oracleracexpert.com

Thursday, September 8, 2016

InnoDB: Unable to lock ./ib_logfile0, error: 11

One of our MySQL servers got restarted and after restart MySQL instance was not coming online.

I see below error message in mysqld.log

InnoDB: Unable to lock ./ib_logfile0, error: 11
InnoDB: Check that you do not already have another mysqld process
InnoDB: using the same InnoDB data or log files.
InnoDB: Error in opening ./ib_logfile0
160712 19:16:34 [ERROR] Plugin 'InnoDB' init function returned error.
160712 19:16:34 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
160712 19:16:34 [ERROR] Unknown/unsupported storage engine: InnoDB
160712 19:16:34 [ERROR] Aborting
160712 19:16:34 [Note] /u01/mysql/5.5.22/bin/mysqld: Shutdown complete

I receive below error message when trying to access the database from command line

# mysql -u root -p
Enter password:
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/u01/mysql/5.5.22/mysqld.sock' (2) 

It looks like the sudden server crash didn’t update the logfile or datafile header properly and not able to lock to bring the instance up.

After research I was able to fix this error by following below steps

1. Go to the data directory and backup the ./ib_logfile0 and copy a new one
$ mv ib_logfile0 ib_logfile0.bak
$ cp -a ib_logfile0.bak ib_logfile0

2. Restart the mySQL database

Thanks,
Satishbabu Gunukula, Oracle ACE
http://www.oracleracexpert.com