DATA Guard Logical Standby v.s. Streams Apply (10gR2, rac --> rac )
730043Mar 8 2010 — edited Mar 9 2010Greetings -
We currently have a 3 node cluster, doing a 'Schema' capture, with a 2 node cluster serving as the apply side. Both are on 10gR2 (solaris 10)
We have been experiencing apply latency due to large transactions. The way logminer/streams evaluates the arch logs, it converts each updated row into a transaction as part of a transaction set, using 'decode (' statements.
I am under the impression a physical standby will do the same thing. But what about a logical Standby ?
(this from the Oracle Documentation)
[10g Concepts|http://download.oracle.com/docs/cd/B19306_01/server.102/b14239/concepts.htm#SBYDB00010]
...Contains the same logical information as the production database, although the physical organization and structure of the data can be different. The logical standby database is kept synchronized with the primary database though SQL Apply, which transforms the data in the redo received from the primary database into SQL statements and then executing the SQL statements on the standby database.
Does anyone know firsthand if SQL APPLY re-issues the original sql, or if it relies on the 'decode' command as well ?
Thanks
The Nets Edge