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Oracle VS MySQL file architecture

Oracle VS MySQL file architecture

For  Oracle database administrator, when it comes to learn new technology it always starts from comparison with respect to physical or logical architecture. Physical file architecture  comparison is given below , I hope it will be very useful for Oracle or MySQL database administrators who want to learn either of these databases.

Oracle database consist of following files

  • init. ora

Parameter file for database instance. It contains information about location of data, archive, redo and other log files. It also contains memory settings for the instance and remote locations.

  • Control file

It holds the information of each and every data file, redo log file locations and backup information starting time and ending time

  • Data file

It stores the data which includes user data and undo data. Extension of these files is “.dbf”. Names format and location of these files are defined in init.ora file.

  • Redo log file

It is part of an oracle database. It’s the main purpose is to recover the database. It’s extension “.log”

  • Archive log

It is a group of redo log files to one or more offline destinations, known collectively as the archived redo log. These logs contains all the transactions including redo statements which are applied to or can be applied to the database.

MySQL Database consists of following files:-

  • my.cnf

Parameter file for database instance. It contains information about location of data, archive, redo and other log files. It also contains memory settings for the instance and information about remote host for replication of data.

  • mysql-bin.index

This file contains information binary logs (archive logs in oracle called bin logs in MySQL). This information is stored in control file in oracle.

  • Redo log file

In MySQL ib_logfile0 and ib_logfile1 are called redo log files all transactions are stored before they are committed to disk. These transactions are translated into binary logs after commit. We can have more than 2 files in more than 1 groups as well.

  • Binary log ( archived logs in oracle)

These logs are same as archived logs in oracle. These files contains all the transactions or rollback statements committed to the database / disk. These files are translated into relay logs on remote destination for data replication but in oracle archived logs are created on remote destination to be applied on standby databases.

 

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Raja Naveed