Database Administrator

1. added the oinstall user group and dba user group, added Oracle users, and added them to these two user groups. The default group is the dba user group;2. Set oracle user environment variables Command:Vi ~ /. Profile (". "indicates hidden files, h-

1. installation environment requirements1.1-Log On As A root userSu-1.2-RAM requirementsOn Linux X86:At least 1 GB memoryGrep MemTotal/proc/meminfoRelationship between Swap and RAM     On Linux X86-64At least 4 GB memoryGrep

Recently, when I was working on two sets of AIX5.3 + 10.2.0.4 RAC, I didn't find the AIX Toolbox for Linux Applications for POWER Systems CD. To make it simple, I used RSH as the remote node file copy method. After the database is installed, it is

, SET AUTOTRACE ON EXPLAIN(Set autot on exp)The SQLPLUS command displays the execution plan while executing the SQL statement. The purpose of setting EXP (LAIN) is to only display the execution plan without showing statistics ..2. SQL> explain plan

Oracle query ora error number and solution tips racle error number and solution tips a friend often asks me about ORACLE similar ora-00109 error information, in fact, our ORACLE system has already explained various error messages in detail for us.

When a table has hierarchical data, you can use hierarchical query to display the data results more intuitively and the hierarchical relationship between the data. The following query example: Select lpad ('', 3 * (t2.grl _ grouplevel-1) | t1.cif _

SQLiteIs a lightweight database that compliesACIDAssociationRelational Database Service (RDS) is already used in many embedded products. It occupies very low resources and may only require several hundredKThe memory is enough. It

When developing Oracle Forms, do I have such a requirement? I need to execute an operation every time I leave a row of records. WHEN-VALIDATE-RECORD is used, but in actual testing, how can this problem be solved sometimes? Have you tried

ERROR:ORA-00257: archiver error. Connect internal only, until freed. (1) SQL> select * from v $ log; GROUP # THREAD # SEQUENCE # bytes members arc status FIRST_CHANGE # FIRST_TIM If all the arcs are found to be NO, the system cannot perform

Sqoop is a tool used to transfer data between Hadoop and relational databases. It can import data from a relational database (such as MySQL, Oracle, and S) to HDFS of Hadoop, you can also import HDFS data to a relational database. Sqoop User Guide

Note that Ubuntu 11.04 MySQL 5.1 is used. Windows estimates are different .. Study for yourself !! 1. It is not recommended to use the BACKUP and RESTORE commands after logging on to MySQL. Later versions may be removed .. So stop using it! 2. Use

Why use? 1. If you need to apply the same query multiple times in a complex query, use WITH to implement code reuse; 2. WITH query is similar to retaining the query results to the user's temporary table. IO can be reduced in large and complex

This article mainly explains the problem of MySQL optimization in the CentOS system, and describes some basics of MySQL optimization. MySQL optimization is divided into two parts. Physical server hardware optimization and MySQL optimization. The

Many Oracle EBS developers have encountered how to submit a concurrent request in Form or PLSQL?It is actually relatively simple. For more information, see PLSQL. DeclareV_req_id Number;BeginFnd_global.apps_initialize (4394,505 93, 660, 0 );

Problem: "Ora-01045: user system lacks create session privilege; logon denied" appears when you log on with PL/SQL ". Cause: the user has no permission to create a session. In Google, find the following description: What does "ORA-01045: user

This often happens in Oracle, where ORA-02291: violates the full constraints (*)-parent keywords not found The following describes the possible causes: Scenario: A field in Table A is A foreign key associated with A field in Table B. This

SQL> select file_id, tablespace_name, file_name, autoextensible from dba_data_files where tablespace_name like 'test _ T % ';   FILE_ID TABLESPACE_NAME FILE_NAME AUTOEX ----------------------------------------------------------------------- 7

Symptoms: the Database is open or can be connected to the Database from sqlplus. When you connect to the Database from the web, you can find the Database Instance, Listener, agent Connect to Instance is normal, but clicking 'database' cannot enter

Today, I started to understand the Oracle architecture and want to write down every part of the learning records. If something goes wrong, please point it out. Thank you. Related reading: Oracle System Overview-Data Dictionary Oracle System Overview-

View Oracle Database Table lock example-Fault Locating 1. Start a session session1 (actually, you can establish a connection with the database through a third-party software or directly use sqlplus) SQL> select sid from v $ mystat where rownum =