asit

• Jun 9th, 2012

 

log switch ::suppose we have two redo log files LOG A, LOG B.
when transaction(DML) are occurred in Database then they are recorded in LOG A. When LOG A is filled up, a log switch occurs, All new transactions are recorded into LOG B.

This process is cyclic. because after LOG B is filled up then again log switch occurs and transaction are again recorded into LOG A. The previous transaction information in LOG A is then over written. Then archivelog/noarchivelog mode comes into picture