Oracle

Oracle View native Service nameSelect Global_name from Global_name;Database Listener.ora# Listener.ora Network Configuration File:e:\app\chenjz\product\11.2.0\dbhome_1\network\admin\listener.ora# Generated by Oracle configuration

Here is the conversion function To_char Select To_char (sysdate, ' yyyy ') from dual;Select To_char (sysdate, ' Fmyyyy-mm-dd ') from dual;Select To_char (sysdate, ' Yyyy-mm-dd ') from dual;Select To_char (sysdate, ' DDD ') from dual;

1. Create user (requires DBA authority to log in)Create user username identified by password;After you create a user, you authorize it, and if you do not authorize it, you will not be able to log in to the database or do anything:Grant

Dblink's primary role is data access between two databases (1) Global_name View select * from Global_name; (2) View local global_names parameters show parameter Global_ Namesname TYPE VALUE-------------------------------------------------------------

In recent days has been the problem of oracle-sql, involving a number of things that are not used in peacetime, and therefore here depressed for a long time. Now the problem has been solved, though not perfect. But let's share it with everyone. One

Oracle provides a inverted inverted function reverse, but this function cannot be grouped upside down, this article provides a function that can be grouped upside down, as follows:CREATE OR REPLACE FUNCTION reverse_f (p_str VARCHAR2, P_delimiter

1. What does the index do?Answer: The index is used in the database to improve query efficiency.Add: Too many indexes can significantly reduce the efficiency of DML statements, and the principle of indexing is to build on fields that are frequently

Switch to Oracle UserSu-oracle #目录转到oracle用户的HOME下, together with the user's shell to switch, only the environment variable that switches Shell,path is valid. Su only switches identities, and the shell environment is still the original user's shell

1. View the table space and the corresponding nameSql> SELECT file_name,tablespace_name from Dba_data_files;2, query the system users and the corresponding table spaceSql> select Username,default_tablespace from Dba_users;3. Query the table space of

What is consistent reading?Consistent reading refers to a change in the middle that is ignored from the moment of query.Examples ShowFor example, I have two accounts, a, B. A has 1000 pieces and B has 1000 fast. When I query the query speed is

Error logging: Invalid source path '. /stage/components/oracle.jdk/1.5.0.17.0/1/datafiles ' specified for unzip. This error should be I only unzipped the first compressed package, not decompression the second one.2. Another problem is that

The purpose of the SQL Union All directive is to merge the results of the two SQL statements together. The difference between SQL union All and SQL Union is that SQL Union all lists every qualifying data, regardless of whether the database is

Oracle has to start two services:1.oracleserver***. (' * ' means that the database name is also known as an "instance" and a service represents a database)2.oracleoradb11g_home1tnslistener. (only start this to connect to the database via JDBC)Oracle

Project, use a sequence as a single number, the framework is used by SSH, when the DAO layer to fetch, run times wrong to dual is not mapped,[select *.nextval nextvalue from dual]Later, the inspection found that the way to get the wrong, so change

Can't login em, execute emca-config dbcontrol db do not know always default 1522 port number, helpless, Google some, from the second step below to start execution ... (My monitor is fine)1. Open the net config Assistant in the Oracle Configuration

In the default, the Oracle database under Linux will not boot, but many times we need to boot the database, so we need to set up the following methods:System Environment: CentOS 6.5Oracle Version: 10.21. Modify the/etc/oratab file #

Case of Oracle listening service startup failure and oracle listening failure When a database is restored on the ORACLE test server, errors such as TNS-12541, TNS-12560, and TNS-00511 occur when the listening service is started, as shown

Oracle11g installation and configuration EM You cannot log on to EM. If you execute emca-config dbcontrol db, you do not know that the default port number is 1522. But google will execute the command in step 2... (My listeners are fine) 1. Open

Oracle Auto-start By default, Oracle databases in Linux do not start on their own, but many times we need to start the Database on their own, so we need to set the settings as follows: System Environment: CentOS 6.5 ORACLE version: 10.2 1.

Oracle Storage StructureOracle Storage StructureStorage Structure-Table Storage StructureTable space: A table space is composed of one or more files. The space capacity of a table space is the total size of multiple files.Create an intermediate