Oracle

1. The concept and role of cursorsThe cursor can manipulate the query's result set as the user would like to manipulate the array, and it can be visualized as a cursor with a change, and its actual line is a pointer to the oracle that holds the data

The attentive little companion could find that we were in Gv$pdbs, and did not find con_id=1,con_id=0In fact, if you take a careful guess, you should be able to guess:Because CDB is made up of root container,seed pdb container,0 or multiple PDB

# Oracle Database backup instructions are exported in EXPDP mode Log in to the database using an administrator Querying the logical directoryselect * from dba_directories; Creating a logical Directorycreate directory [name] as

First, prepare the target database1. Ensure that the target database's character set Nls_characterset and the source database are consistentSELECT * FROM Nls_database_parameters2. Create a database table space to migrateSelect Tablespace_name from

---restore content starts---1. Determine if the VM's hard disk space is df-h enough, the hard disk space free disk 15G is more secure2. Identify the network and require remote connect ifconfig3. Verify kernel. Confirm that the Linux version meets

Basic Relationship: Database---Table space---data segment---partition---data blocktable Space (tablespace)A tablespace (tablespace) is a logical entity that contains a physical data file that holds all the data available to the database, so the size

------------I do not have him, but the hand is ripe, humble and foolish, and eager to be hungry-------------Summary One version:The database definition language for theLanguageDDL(data definition) . Used to create various objects in the database.

SessionBecause every login requires a session, this parameter effectively determines the maximum number of concurrent users in th E system. You should all set this parameter explicitly to a value equivalent to your estimate of the maximum number of

Task Name: Schema Elon Data migration to schema TIAN in the production environment########################################Test two: Test parameter remap_tablespaceExport all data for schema Elon:[[Email protected] ~] $EXPDP system/xxxxxx

System.Data.OracleClient Microsoft-provided connection library, but it is outdated, not recommendedTwo. Oracle.DataAccess.Client (odp.net) Oracle provides a database access class library.Three. Oracle.ManagedDataAccess.dll (Odp.net Managed) is also

1. How to view the definition of sequence2.dba_sequences definition of related words3. How to Modify sequence*************************************************************************************************************** *****************************

2011-08-24Alter user Scott account unlock change users unlockConn Scott/tiger re-login with the above userSELECT statement:1. DESC EMP describes the EMP table and lists the basic information of the table.2. Data type: Number (7,2) 7 digits, 2

Access Oracle with CMDSqlplus username/password @ip address: 1521/database nameLike Sqlplus scott/[email PROTECTED]:1521/ORCL.Syntax format and instance of the SELECT statement　　SELECT * | {[DISTINCT] column | expression [alias], ...} from table;1.

Title Createtime--author:marydon1. Scene reproduction2. Problem resolutionThe Oracle database is not installed on this machine, so the plsql does not start.3. SolutionCopy the instantclient_10_2 to the Plsql installation directory--The absolute path

The Oracle decode function, regardless of whether the result of the query satisfies ' PRIMARY ', is executed by the SELECT statement in the parameter, and you know by looking at the execution planSet Autotrace traceonlyselect decode(database_role

1. Index① in a relational database table, each row in the table is identified with a rowid in order to be able to find the data . RowID tells the database the exact location of the row, including the file where it resides, the block in the file,

6, how to use the display cursor,? How do I traverse a circular cursor?① using Display Cursors⑴ declares a cursor: divides the storage area, noting that the SELECT statement is not executed at this time.cursor cursor name (parameter list) [return

I, like everyone else, encountered a problem, that is, how to remove Oracle from their own computer clean, many people find it difficult to uninstall Oracle Clean, and then choose to reinstall the system, because it can not solve the Oracle does not

-- view: view (virtual table), not occupying physical space! --  if there is no permission -- create or replace   view  teacher_view as select tname,sal from teacher --   Query view select * from teacher_view =======pl/sql=======***

Win 10 System, Oracle one G R 2, install directory C packing directory1. Stop All Oracle ServicesOpen the Services window and turn off all Oracle Services2. Running Oracle Universal Installer uninstalling OracleOn the desktop, click