oracle cloud tables

How to view the definition of tables, views, indexes, stored procedures, and triggers in Oracle View table definitions: Sets long 999999 Select dbms_metadata.get_ddl ('table', upper (' table_name') from dual; View the view definition: Select text from user_views where view_name = upper (' view_name '); View the index definition: Select dbms_metadata.get_ddl ('index', upper (' index_name') from dual;

Advantages of using partitions: 1. Enhance usability: If a partition of a table fails, the data in other partitions is still available; 2, Maintenance Convenience: If the table of a section of the fault, need to repair the data, only repair the partition can; 3, balanced I/O: You can map different partitions to disk to balance I/O, improve the performance of the entire system; 4, Improve query performance: The query on the partition object can only search their own care, improve the speed of

As we all know,TableInOracle DatabaseIn addition, fragmentation has a great obstacle to Oracle database space management. At the same time, if the disk space in the segment is large, it will also affect the database performance. Although the local hosted tablespace technology is adopted in Oracle10G, it can eliminate the negative impact to the maximum extent. However, when the data volume is large and the disk volume increases, the database query effi

Temporary tables in Oracle can be divided into session-level temporary tables and transaction-level temporary tables.The role of temporary tables: for large amounts of data we just need to query a subset of the result sets so that we can use temporal tables.1. Session-Level

Tags: new features show row statement query attribute handling cannot export replicationThere is a new feature in ORACLE 11G that does not allocate segment when the table has no data to save space. Workaround: 1) Insert a row, and then rollback will produce segment. The method is to insert data into the empty table and then delete it, resulting in segment. When exporting, you can export empty tables. 2) Set

1. Knowledge Points: Can be read against the following record screenSql>--Creating table sql> Create tables test1 2 (TID number, 3 tname varchar2, 4 hidatedate date default sysdate); Sql>--using as and subqueries to build tables quickly sql>--Create tables: include employee number name monthly Salary Department name sql> CREATE TABLE Empincome 2 as 3 select Empno

Tags: exp DMI span BSP centrally run lap div effectDMP tables Import and export from Oracle databaseImport: Start-to-run input cmd enter # #语法格式为: Imp username/password @ip address/database name file= ' dmp file path ' full=yC:\users\administrator>imp Testuser/[email PROTECTED]/ORCL file='C:\Users\Administrator\Documents\szj\wzcl2.dmp'Full=y # #下面为运行后效果import:release 11.2.0.1.0-production on Wednesday M

Tags: database transaction session TEMP Table OracleIn addition to saving permanent tables, the Oracle database can also establish temporary table temporary tables. These temporary tables are used to hold data for session sessions, or to store data in a transaction. When the session exits or the user submits a commit a

process, we found that tables in the read-only tablespace can be dropped. Why?As mentioned above, each database will have an ONLINE tablespace during operation. The tablespace name is SYSTEM, and the data dictionary is saved in the SYSTEM tablespace, and database objects such as stored procedures, triggers, functions, and packages in PLSQL. When you delete a database using DDL, It is the operating SYSTEM tablespace.

primary key.3, Maintenance Convenience: If a partition of the table fails, you need to repair the data, only repair the partition; You must redefine the table in the same outline.4. You cannot have a NOT NULL constraint on new columns until the redefine operation is complete.5. The table cannot contain long, bfile, and user types (UDTs).6. The linked list (clustered tables) cannot be redefined.7. The table cannot be redefined in SYS and the system ou

Tags: Oracle tables EXPDPScenario: There are 2 Oracle users, usera default tablespace tablespacea, userb default Tablespace tablespaceb.Now you need to export the system tables in UserA (the table that starts with SYS in the user tablespace) to UserB, overwriting the UserB system t