Oracle

The most effective way to understand the various Connection Methods of Oracle is "". In practice, we should have a deep understanding of the concepts and effects of inner connection, left outer connection, right outer connection, and full outer

-- Select sess, a process statement for table locking and table locking. sid, sess. serial #, lo. oracle_username, lo. OS _user_name, ao. object_name, lo. locked_mode from v $ locked_object lo, dba_objects ao, v $ session sess where ao. object_id =

Starting from 10 Gb, oracle began to provide Shrink commands. If our tablespace supports automatic segment space management (ASSM), we can use this feature to narrow down the segment, that is, reduce the HWM. Segment shrink is divided into two

The count method of displaying the content with the field type of number and length greater than 16 bits in pl/SQL query is scientific notation. After searching, the following solution is found: 1. in toad, choose view> option> data> display large

The content of this article includes deleting and modifying tables, deleting and modifying fields, deleting and modifying primary keys, foreign keys, unique, non-empty, and default constraints, and viewing all tables of the User: select * from

Two tables a (x, y, z) B (m, n, x) in the left-side join statement of the select query are usually written as select. *, B. m from a left join B on. x = B. x a will certainly display the content that meets the conditions, but when B does not display

1. query table space usage SELECT. tablespace_name "tablespace name", total "tablespace size (MB)", free "tablespace remaining size (MB)", (total-free) "tablespace used size (MB )", ROUND (total-free)/total, 4) * 100 "usage %" FROM (SELECT

1. Update the view. In addition to single tables, update, insert, and delete can also be applied to views and subqueries, but there are various restrictions. Restrictions on the www.2cto.com view (subquery:1. No set operators (sum, difference, and

Online redefinition and modification of table structure: database version: SQL> select * from v $ version; BANNER Upgrade Oracle Database 10g Enterprise Edition Release 10.2.0.3.0-Prod PL/SQL Release 10.2.0.3.0-Production www.2cto.com CORE 10.2.0.3.0

Oracle SQL * PLUS Common commands related to user operations 1. add database users: (user01/pwd) [SQL] create user user01 identified by pwd default tablespace users Temporary TABLESPACE Temp; www.2cto.com 2. authorize user01: [SQL] grant connect,

Oracle Database dictionaryIn most data dictionary views of Oracle, there are view families like DBA_TABLES, ALL_TABLES, and USER_TABLES. There are more than 100 view families in Oracle. The following table lists the most important and commonly used

1. Table Name and column naming rules start with a letter, no more than 30 characters, cannot use reserved words can only use A-Z, a-z, 0-9, $, #. 2. The data type is www.2cto.com (1) and the char length is 2000 characters. For example, if char (10)

Oracle encountered a ORA-04063 when creating a Job SYS. DBMS_INTERNAL_LOGSTDBY solution on the project you need to use the job to reset the sequence at the beginning of each month, on my local Oracle the job was created successfully,But in the

PLSQL Developer or Toad does not install the Oracle client to connect to the database. In order to simplify the use of Oracle on a personal computer and avoid occupying unnecessary resources, you can not install the Oracle client.The method is to

The garbled data in the oracle varchar2 field is extracted due to work requirements. During the migration of a batch of data, the varchar2 field of a table should be composed of numbers, but garbled characters appear. For example.Now we need to

Common Oracle HINT usage 1. /* + ALL_ROWS */indicates to select the overhead-Based Optimization Method for the statement block and obtain the optimal throughput to minimize resource consumption. example: SELECT/* + ALL + _ ROWS */EMP_NO, EMP_NAM,

ORA-01502: index 'xxx. xxxx' or partition of such index is in unusable state. Solution: Log On With DBA and run the following script. 01. Log On With DBA permission, run 02 -- fix all indexes in the UNUSABLE state, and rebuild it to 03declare04 --

Oracle obtains the desired data analysis requirements from string resources: Order Analysis analyzes the transaction data trend based on the game, account level, game account occupation, zone server, and price range. Objective: order processing

Related Links: Exploring the RMAN_01 concept of ORACLE http://www.bkjia.com/database/201205/132243.html Explore the basic use of RMAN_02 in ORACLE http://www.bkjia.com/database/201205/132329.html ; Explore ORACLE RMAN_02 consistent backup http://www.

ORACLE Date and Time Function Daquan TO_DATE format (take the time: 2007-11-02 13:45:25 as an example) www.2cto.com Year: yy two digits two-Year display value: 07yyy three digits three-Year display value: 007 yyyy four digits four-digit year display