Latest Answer : Disk shadowing or mirroring is done either using a software or a hardware utility called RAID.  Disk shadowing enables another disk to take-over from a failed hard disk avoiding any downtimes. Generally Hardware fial-overs are enabled on all servers. ...

 Due to insufficient Shared SQL pool size. Monitor   the ratio of the reloads takes place while executing SQL statements.   If   the   ratio   

 Database buffers are cache in the SGA used to hold the data blocks that are read  from  the  data  segments in the database such as tables, indexes and clusters DB_BLOCK_BUFFERS 

 Number  of  times processes repeatedly query the dictionary table is called recursive  hints.  It  is due to the data dictionary cache is too small. By increasing the SHARED_POOL_SIZE 

 Changes made to entries are written to the on-line redo log files. So that they can be used in roll forward operations during database recoveries. Before  writing  them  into  

 PCTFREE parameter Row size also reduces no of rows per block. 

 It  will  try  to  fit  the transaction in a cyclic fashion to all existing extents.  Once it found an extent is in use then it forced to acquire a new extent (No. of 

List  the  sequence  of  events  when a large transaction that exceeds beyond  its  optimal  value  when  an  entry  wraps and causes the rollback segment to expand into another extend. Transaction Begins. An entry is made in the RES header for new transactions entry Transaction acquires blocks in an extent of RBS The  entry  attempts to wrap into second extent. None is available, so that the RBS must extent. The

 Calculate the total header sizeCalculate the available dataspace per data blockCalculate the combined column lengths of the average rowCalculate the total average row size.Calculate the average number 

It  is  possible  to  use  raw  devices  as data files and what is the advantages over file. system files ?

 Yes. The advantages over file system files. I/O  will  be  improved  because  Oracle  is  bye-passing the kernnel which writing into disk.Disk Corruption