Incremental backup of database(RMAN)

incremental backup of database

only possible with rman
two types of incremental backup are there
1.differential(default)====contains changes from last level 1 or 0 means the prev
2.cummulative=======contains changes from last level 0



1.differential(default)
saves time ,space, band width
only backups the change
rman target /
level 0 : sunday
level 1 : every other day

rman> backup incremental level=0 database tag='LEVEL0-SUN'

tag='LEVEL0-SUN' IS NAME OF BACKUP THAT CONtrol file knows

rman > list backup summary;

sqlplus > create a table days (varchar (20));

insert mondsy

rman> backup incremental level=1 database tag='LEVEL1-MoN'

takes only the change now(data blocks)

insert tuesday


rman> backup incremental level=1 database tag='LEVEL1-TUE'

insert wed

rman> backup incremental level=1 database tag='LEVEL1-wed' and so on to sat


crash the database intensionaly

restore


rman>startup nomount;
rman> restore controlfile from 'backup piece name latest';
rman> alter database mount;
rman>list backup summary;
rman>restore database;
rman>recover database; (by def it will rec as uch it can)
rman> alter database open resetlogs;


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2.cumulative (backs up everything changed from last 0 level)

rman> backup incremental level=0 cumulative database tag='LEVEL0-cum-SUN';

create table days(name varcahr(2))

in monday

rman> backup incremental level=1 cumulative database tag='LEVEL1-cum-moN';


#datablock in dbf has scn in header ,rman checks this scn with the prev backup taken



drop ts records in alert
so check in alert for drop ts

and take ur db to seq back just before drop


select sequence#,first_change# from v$log_history where sequence#='4';

recover database until change change# using backup controlfile;

alter databse open resetlogs;