MARKS TUTORIAL

What is the meaning of database version in Oracle? When I say that I have installed Oracle database 11.2.0.2.0, what actually is this 11.2.0.2.0 Let’s see what all this is about: Oracle database software has a version number. Say our database version is 11.2.0.2.0 11 .2.0.2.0: The first digit is the major release number.  When we say 9i, 10g or 11g we mean the major release number. 11. 2 .0.2.0: This second digit is the maintenance release number. This is usually called only " release ". For example when you say 11g Release 1 or 11g Release 2 in fact you are mentioning maintenance release number. Maintenance releases are full installations. It means that all files are replaced during upgrade. Maintenance releases contain bug fixes and new features for database. 11.2. 0 .2.0: This third digit is the release number for Oracle application servers. For database software, it should be 0. 11.2.0. 2 .0: The fourth digit is called component specific releas

How to create MySQL Database Backup using Shell Script I am going to represent a general Mysql Backup Script here. -- You have to create appropriate directories for the backup task and make sure that file permission on configuration file, script file, lock file etc. are appropriately set so that only the intended user can access the various files and no one else.  -- MySQL user (os user) that is used to create the database backup has a configuration file in his home directory that stores the password that is required to login into the database. -- I have commented the uuencode command, you can test the script and mailing capability of the server and can uncomment the command to send mails if required. -- The script is running under mysql user therefore he will have the rights over the backup and log files that will be created in the process. I had put my script under /dba/mysql/scripts directory and give mysql appropriate privileges to run it. You can pla

How to deal with UNDO space usage alert Oracle Database creates and manages information that is used to roll back, or undo, changes to the database. Such information consists of records of the actions of transactions, primarily before they are committed. These records are collectively referred to as undo. Undo records are used to: Roll back transactions when a ROLLBACK statement is issued Recover the database Provide read consistency Analyze data as of an earlier point in time by using Oracle Flashback Query Recover from logical corruptions using Oracle Flashback features When a ROLLBACK statement is issued, undo records are used to undo changes that were made to the database by the uncommitted transaction. During database recovery, undo records are used to undo any uncommitted changes applied from the redo log to the datafiles. Undo records provide read consistency by maintaining the before image of the data for users who are accessing th

How to rename or move a datafile in oracle Renaming/Relocating a Data File or Tablespace 1. Take the tablespace offline: ALTER TABLESPACE USER_DATA OFFLINE; 2. Copy the file to the new location by using OS commands on the disk. 3. Rename the files in the database by using one of the following two commands. The number of data files specified before the keyword TO should be equal to the number of files specified after the keyword. ALTER DATABASE RENAME FILE ‘/disk1/oradata/DB01/user_data01.dbf‘, ‘/disk1/oradata/DB01/userdata2.dbf‘, ‘/disk1/oradata/DB01/user_data03.dbf‘ TO ‘/disk2/oradata/DB01/user_data01.dbf‘, ‘/disk2/oradata/DB01/user_data02.dbf‘, ‘/disk2/oradata/DB01/user_data03.dbf‘; Or ALTER TABLESPACE USER_DATA RENAME DATAFILE ‘/disk1/oradata/DB01/user_data01.dbf‘, ‘/disk1/oradata/DB01/userdata2.dbf‘, ‘/disk1/oradata/DB01/user_data03.dbf‘ TO ‘/disk2/oradata/DB01/user_data01.dbf‘, ‘/disk2/oradata/DB01/user_data02.dbf‘, ‘/