Oracle

Set Oracle PL/SQL time display format NLS_TIMESTAMP_FORMAT TIMESTAMP in Oracle the time field of the display format of Oracle Database we usually use timestamp format, before not set, the queried data is similar to "27-1-08 12.04.35.877000 am

1. The most common one is update t1 set B = (select B from t2 where t1.a = t2.a). However, pay attention to the impact of null values. If you are afraid of the impact of null values, update t1 set tname = (select sname from t2 where t1.id = t2.id)

Comparison of insert, copy and insert append operations in oracle is still due to database migration. The execution speed of insert, copy and insert append is tested. Environment: migrate oracle9i to oracle11g, linux system. The table has been

Once the database fails to be installed, it is very troublesome to uninstall it. After collecting data from various aspects, we will summarize the methods for uninstalling oracle databases. I tried it. OK. 1. It is very easy to uninstall Oracle on

Oracle common data dictionary 1. query all tables under a user select table_name from all_tables where owner = 'Scott '; 2. query all fields (columns) in the EMP table) select * from all_tab_columns where table_name = 'emp'; www.2cto.com 3. select *

Summary of oracle simple learning (6) -- database transaction links: oracle simple learning Summary (1) -- sqlhttp: // www.bkjia.com/database/201210/159545.html#oraclesimple learning Summary (2) -- Query Summary (3) -- function compute (4) --

Overview of Oracle default users when installing the Oracle database, Oracle will automatically create a group of users who can log on to and manage the database: username initial Password Logon identity descriptionSys change_on_install sysdba or

ORA-27101: shared memory realm does not exist problems occur when logging onto SQLPlus: ORA-01034: ORACLE not avaiableORA-27101: shared memory realm does not exist Process ID: 0 Session ID: 0 Serial Number: 0 solution: 1. cmd-sqlplus/nolog; 2. Log

Select column_name, data_type, data_lengthfrom all_tab_columns where table_name = 't_ cakey' select * from user_tables -- query the table owned by the current user select * from dba_tables -- users with DBA permission can query all the tables select

Oracle dataguard configuration Oracle dataguard Configuration System linux Description: master server ora10g01 (192.168.1.252) Standby server listen 10g02 (192.168.1.253) both machines are installed with the same version of the database master

The Storage Level System database in the Oracle database consists of one or more tablespaces. A table space is a logical storage container in Oracle. It is located at the top of the storage hierarchy and contains one or more data files. First,

If plsql is not installed on the oracle client, and plsql is used for Chinese garbled question marks, and oracle is a green version, it is ready for decompression, and the Windows 7 64-bit test is passed. PLSQL9 Chinese Green Edition:

Oracle SQL converts a varchar type data into multiple rows of Results records. Today, when I create a report, I want to use an SQL query to query the final results. However, I encountered some problems during implementation, one field I found is

Oracle-based user management 1. oracle-Based Default users sys change_on_install [as sysdba] system manage scott tiger 2. start listening lsnrctl start listening name in cmd (default listening name is not writable) 3. Start the instance

In the use cases of partition and subpartition in super large tables, partition and subpartition are two common keywords in super large tables. They are mainly used for partitioning to improve data reading efficiency. (For more information about

Solution and steps for oracle listening failure I described the failure to start Oracle listening is a solution that can be started normally after the installation is complete, because the network ip address is changed or the computer name cannot be

Oracle Database role management 1. The super administrator creates the role myrole (a set of permissions) SQL> create role myrole; the role has been created. Www.2cto.com 2. grant the role myrole SQL> grant create session and create table to myrole

The use of the case end and decode functions in the select clause can be implemented using the case end and decode functions to compare the size of the Field Values in the select clause of the Oracle database. For example, www.2cto.com queries the

ORACLE 11g listening file log is too large, causing client connection failure problem yesterday, the client program actually appeared, no valid listening, unable to connect to the database, then view the WINDOWS Server ORACLE listening service,

If a lock wait occurs when querying the lock table in oracle and unlocking the table, we may want to know who has locked the table and who has waited. The following statement can be used to query who has locked the table: www.2cto.com SELECT/* +