What’s New with Oracle Data Guard

What’s new with Oracle Data Guard

Larry Carpenter – Oracle
Sreekanth Chintale – Dell

Mirrored copy is not good for
 – up to date reporting
 – testing while providing continuous protection
 – fast online backups
 – preventing mirroring of physical corruptions

Traditional DR does not provide what people need

DG 11g has evolved to be part of an integrated part of IT operations
 – sync reporting replicas
 – snapshot sby for testing
 – validation prior to apply
 – fast failover and switchover
 – automatic failover

improved data protection
HA
more manageability
increased ROI

improved data protection
 – faster redo transport
     new streaming protocol, async and arch transport. eliminates internal network acks during redo transport. Result is more efficient network utilization, less frequent buffering of workload peaks at primary location, faster gap resolution. 40MB/sec throughput with less than 1ms buffer spool between primary and standby.
COMPRESSION=ENABLE
 – advanced compression
     dataguard aotomatically compresses data transmitted to resolve
gaps. reduces xmission time 15-35%, bandwidth consumption by 35%. It
does require advanced compression to be enabled.

    log_archive_dest = service=dbname ASYNC
 – lost write protection
      faulty storage hardware/firmware may lead to lost writes leading to data corruption. 11g will catch this through data guard. A redo can verify from the physical standby.
     alter system set db_lost_write_protection=typical;

HA
 – faster redo apply and SQL apply
      (Redo Apply)OLTP – 95% improvement 24MB/sec vs 47MB/sec

      (Redo Apply)Batch workload – 130% improvement (48MB/sec vs 112MB/sec)

      (SQL apply)LOB inserts – 50% improvement

      (SQL apply)support for DDL in parallel on standby. this is a potentially big probom on 10g and 9i

      (SQL apply)OLTP – 19-22% improvement
 – faster failover and switchover
      automatic failover for max performance mode. default setting is 30 seconds,  minimum threshold is 10 seconds. Async mode only.
       OEM will automatically restart the DG observer on a second host if the primary observer host fails.
 – enhanced fast-start failover
       immediate automatic failover foruser-configurable health conditions. condition examples – datafile offline, corrupted control file, corrupted dictionary, inaccessible log file, stuck archived, or any ORA-zyx error
        apps can request fast start failover using API
 – transient logical standby
        execute rolling database upgrades using a physical standby. You can temporarily convert physical to logical and perform upgrade. Once the upgrade is complete, revert to physical standby. This is a big option which allows for rolling upgrades of physical replicas and have the upgrades pushed to primary as well.
 – new grid control HA console

More Manageability
 – SQL Apply
       more data types. XMLTypedata type (CLOB)
       support TDE, encrypted table spaces, FGA, VPD
       role specific jobs – ie, jobs can be defined to run if in primary or if the system is a standby. This allows the same jobs to be on all systems. There is no need to have different jobs on different systems and reconfigure jobs when a system switches.
 – Better RMAN integration
       direct remote instantiation of remote standby database without the need for intermediate storage. New keyword “From active database” for the RMAN process. .
        block change tracking on physical standby databases
        archive deletion policies are enhanced. delete when shipped, when shipped and applied
 – Better security
        sys user and password files no longer required for redo transmission authentication. auth possible using SSL but requires ASO and OID. It issues PKI certificates and ships certs
        redo transport auth can use a dedicated non-sys user. the user must have sysoper privs. This required password for this user to be the same at the primary and all standbys.
 – Mixed Windows/Linux
         physical standby can be done a Windows ald Linux system in the same DG configuration. It required same endianess on all platforms.
 – Enhanced Data Guard Broker
       enhanced for fast start failover. No bounce required to change protection modes from Max Perf to Max avail

Increased ROI
 – snapshot standby
       perserves zero data loss. continuous redo transport while open
read-write. (See notes below from Dell). There will be a new button on the 11g OEM console to make this happen for 11g.
 – active data guard
   – real-time query
   – fast incremental backups

Dell 83% platform Linux, rest Windows. Most 10g database (1168) some 9i (333) a few 8i (57). Spread across manuf, HR, sales, marketing, internal apps. When a database shuts down, the factory shuts down. All of the systems are managed through OEM. Targets (8176), cluster db (326), db instances (1267) hosts (1570), ASM targets (844)

snapshot standby – fully updateable standby. provides DR and data protection. Requires flashback DB. Single command in 11gR1

testing and updates can be done on standby then pushed to production. There is no difference between production and standby.

prepare standby, prepare primary
create restore point on standby
convert physical standby to rw
use rw standby
roll back to restore point
ship redo logs to standby (10g only)
apply redo
make standby again

In 11g the difference is the redo logs are shipped to the standby.In 10gR2 you need to do this manually. There is a whitepaper on OTN that describes this. In 11g this is a single command.  On 11g it does require the data guard broker.

my opinion is that this is a cool technology. This is good stuff that solves some real problems. In my opinion this is going to be something that will have people move to 11g quickly as well as use DGuard and OEM.