tailieunhanh - Oracle Database Administration for Microsoft SQL Server DBAs part 19

Oracle Database Administration for Microsoft SQL Server DBAs part 19 takes the administration topics with which the SQL Server DBA is familiar, translates them into Oracle terms, and then expands on Oracle functionality. Definitions and comparative terms run throughout the book so the SQL Server DBA can easily leverage existing knowledge. This Oracle Press guide also expands on some of the features in Oracle that do not match up directly with SQL Server, and looks at other processes often performed on an Oracle database that would not typically be a standard practice in SQL Server environments | 162 Oracle Database Administration for Microsoft SQL Server DBAs from the recycle bin. The recycle bin has been available since Oracle Database 10g and is on by default. Users have their own recycle bins. NOTE The recycle bin does not provide protection from truncating the data from the table or other data manipulations. However changes like deletes and updates can be handled with commits and rollbacks. The user_recyclebin and dba_recyclebin views show information about the contents of the recycle bin. The dba_recyclebin view has an owner column which lists who owns the object. USQLPLUS desc DBA_RECYCLEBIN Name Null Type OWNER NOT NULL VARCHAR2 30 OBJECT NAME NOT NULL VARCHAR2 30 ORIGINAL NAME VARCHAR2 32 OPERATION VARCHAR2 9 TYPE VARCHAR2 25 TS_NAME VARCHAR2 30 CREATETIME VARCHAR2 19 DROPTIME VARCHAR2 19 DROPSCN NUMBER PARTITION NAME VARCHAR2 32 CAN_UNDROP VARCHAR2 3 CAN_PURGE VARCHAR2 3 RELATED NOT NULL NUMBER BASE_OBJECT NOT NULL NUMBER PURGE_OBJECT NOT NULL NUMBER SPACE NUMBER Since the names of the objects in the database need to be unique by owner and object name the name of the object in the recycle bin is systemgenerated and starts with BIN . Here is an example of a quick query against dba_recyclebin F SQLPLUS select owner object_name OWNER OBJECTNAME WK_TEST BIN 7qfPJ4jvSjOSTM1Vng 0 WK_TEST BIN oxgITJMlRtmNZOVYtw 0 WK_TEST BIN rdtRhxXVSANuLmU6 w 0 original_name droptime from dba_recyclebin ORIGINAL_NAME DROPTIME TAB_CUST_PK 2010-02-04 16 TAB_CUST 2010-02-04 16 TABINVPK 2010-02-04 16 Chapter 6 Database Backup Restore and Recovery 163 Or you can run a SHOW RECYCLEBIN SQLPLUS show recyclebin As you can see from the description of the view and the sample query the object name is definitely unique and the only way to relate it back to the original object is through the original name and owner. The change number and the time that the object was dropped are also provided. Since the object isn t really dropped and the data is there you can actually run queries .

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