[teacher Zhao Yuqiang] use the catalog database of Oracle

One 、 What is a catalog database ？

You may have heard it from other people or books RMAN Restore directory （ It could be some other name ,RMAN Recovery Catalog The translation of English is more complicated , Hereinafter referred to as the recovery directory ）, The expression of others or the vague description in the book , Many friends have been confused about its practical significance and function . in my opinion , Think of it as storage RMAN Backup and restore the database of relevant information （ In physical form, it can correspond to Oracle One of them SCHEMA）.
When the directory is not recovered ,RMAN Related backup information , For example, the path to the archive 、 The backup set path is stored in the control file of the target database , However, considering that control files can't grow indefinitely , And the control file is not only used to store information related to backup , therefore RMAN There is also a dedicated backup information store , This is the recovery Directory , namely ： Catalog database . When the database to be backed up is registered in the recovery Directory ,RMAN The relevant information is stored in the control file （ The control file is actually only part of it ）, More detailed information is stored in the recovery Directory . As shown in the figure below ：

Two 、 Create and use Oracle Directory database for

• First , Use DBCA establish rcat database . The database we created here is ：rcat.example.com. As shown in the figure below .

• Create a new table space in the directory database . Here we set the table space size as 50M.

create tablespace rcat_tbs datafile '/home/oracle/rcat_tbs01.dbf' size 50M;

• Create user , Able to use rcat_tbs Table space , And authorized to use the above table space

create user rcat_owner identified by password;
alter user rcat_owner default tablespace rcat_tbs;
alter user rcat_owner quota unlimited on rcat_tbs
grant recovery_catalog_owner to rcat_owner;

• Use RMAN Log in to the directory database , Use the above to create users

rman catalog [email protected]

• establish catalog

create catalog;

• Add the target database （ That is, the database to be backed up ） Register in the directory database ; Register the target database into the catalog database , As shown in the figure below

rman target / catalog ract_owner/[email protected]

register database;

• Now let's do a simple backup , Here we backup it users Table space . Now RMAN The backup meta information will be written to the directory database , As shown in the figure below .

backup tablespace users;

• Check the information in the catalog database , As shown in the figure below .