Different RollBack Segments in Oracle DBA

Differed  rollback segment If any active transaction is there in a table space, if we make the particular table space Maintains the differed rollback segment for that particular tx. SYS> select tablespace_name, segment_name, segment_type from dba_segments where Segment_type like            ‘%DEFF%’; SYS> save drs User 2 > insert into dept select * from dept; SYS > @ drs SYS > alter tablespace ts2 offline; SYS > @ drs Tablespace_name                            segment_type Ts2                                                          differed rollback Sp file & OMF  [ORACLE managed files ] [server parameter file     SERVER PARAMETER FILE To create sp file SQL> create spfile from p file; dynamically we can change parameters, if our database maintains spfile. The default location for sp file is same as pfile location. i.e. $ ORACLE _ HOME /dbs spfile is a semi binary file where as  pfile is ASCII file SQL > alter system set ramote_login_password file = exclusive SCOPE= MEMORY                                                                            SCOPE = memory;/orspfile;/or both; Changes the parameter’s values in the current running instance only. Scope=spfile  Changes the parameter’s values in spfile only Stop=both Changes the parameter’s values in the current running instance and also in     Note1 -  if we have both spfile and pfile then the ORACLE gives preference to ‘spfile’ Note2 -   the default location of the spifle is the same as the pfile i.e. $ORACLE_HOME /dbs Note3 -    in the presence of the spfile. If we want to start our database by using pfile. Then manually we have to write as SQL > startup pfile=’$ORACLE_HOME/dbs/ init$ORACLE_SID.ora’;   Demo on sp file SQL> desc v $ parameter SQL> select name, isses_modifiable, isinstance_modifiable from v$parameter where name like ‘rmote_login%’; SQL> select name, [sees_modifiable, Isinstance_modifiable from v$parameter where Name like ‘resource_limit%’; SYS > create spfile from pfile; SYS> startup force SYS> sho parameter spfile SYS> sho parameter resource_limit                                         [TRUE] SYS> alter system set resource_limit=false Scope = memory SYS> sho parameter resource-Limit                                         [FALES] SYS> start up force SYS> sho parameter resource_limit                                         [TRUE] (scop=memory is session dependent] SYS> alter system set Resource_limit=false scope=spfile; SYS> sho parameter resource_limit                                         [TRUE] [scope=spfile is not for current session but for next session] SYS> startup force SYS> sho parameter resource_limit                                         [FALES] (NEXT SESSION) Sys > alter system set resource _limit = true scope = both; SYS> sho parameter resource_limit                                        [TRUE] SYS> startup force SYS> sho parameter resource _limit                                        [TRUE] [Scope=both] SYS > create file from spfile; [to synchronies the values in pfile and spfile]   To remove sp file [physically at OS level] Dba12~ cde $ORACLE_HOME/dbs Dba12 dbs] $ rm spfile$ORACLE_SID.ora