Oracle Database High Availability Brandon Kuschel Jian Liu Source: Oracle Database 11g Release 2 High Availability An Oracle White Paper November twp-databaseha-11gr pdf

Overview Human Error Protection Oracle Flashback Technologies Oracle Recovery Manager Data Corruption Protection Fast Recovery Area Oracle Secure Backup Data Recovery Advisor Storage Failure Protection Automatic Storage Management Site Protection Oracle Data Guard Oracle GoldenGate

Oracle Database's HA Solution Set

Human Error Protection Example: Bug in SQL statement Isolation: Preventing errors via access control Faster recovery with Flashback technologies Undo: Query Undo: Versions Query: SELECT * FROM emp VERSIONS BETWEEN TIMESTAMP time1 AND time2 WHERE… Transaction Query: SELECT * FROM FLASHBACK_TRANSACTION_QUERY WHERE XID = transactionID Undo Transaction - Atomicity Full Table Undo Drop Entire Database

Data Corruption Protection Ex: Fault during single read/write operation Two-Phase Commit Prepare: Write to log and lock table Commit: Write to disk if ready then log as committed Prevent corruption by setting parameters Wide range of backup options RMAN (Oracle Recovery Manager) Configure backup and recovery policy Verify backups aren't corrupt Fast recovery backup Stored on disk onsite - secondary storage Only the newest files are stored here Tertiary (remote) backup Backups are copied to tape or uploaded to Amazon S3 Data Recovery Advisor Identifies the available recovery options

Storage Failure Protection Ex: Disk drive crash ASM (Automatic Storage Management) Database-specific RAID Block Repair Automatically: relocate valid blocks from the mirrored copy Manually: relocate specific blocks Rolling Upgrades Keeping application online while upgrading ASM ACFS and ADVM ASM Cluster File System Extends ASM functionality to support all non-Oracle database files ASM Dynamic Volume Manager Provides a general purpose volume management platform for 3rd party file system

Site Protection Ex: fire, storm, power outage Oracle Data Guard options: Standby database up-to-date Standby database is a snapshot Use standby to perform planned maintenance in a rolling fashion Oracle GoldenGate – Distributed databases All databases are active for reading/writing Oracle Streams Standby database options Structure of distributed database

References Oracle Database 11g Release 2 High Availability: Using Oracle Flashback Transaction Query Oracle Recovery Manager Oracle Secure Backup ASM in Oracle Database 10g Oracle Data Guard 11g Oracle GoldenGate 11g Two-Phase Commit Mechanism