Oracle

Nowadays, Oracle databases are favored by more and more enterprises for their high reliability, security, and compatibility. Readers may wish to consider the following aspects to ensure the permanent performance of Oracle databases. PartitionBased

Change the table structure 1. Edit table fields Modify the Data Type of a column (generally, the length is limited and there are many restrictions when you change it to a different type ): Syntax: Alter table name MODIFY (column name, data type

  Introduction to the three configuration files of ORACLE Overview In the oracle installation directory $ HOME/network/admin, sqlnet is often seen. ora tnsnames. ora listener. ora files except tnsnames. ora, the detailed usage of the other two files

  ORACLE10gr2 data import MySQL SolutionMySQL GUI Tools1. Download "MySQL GUI Tools" on www.mysql.com;This installation is for WINDOWS. : Http://dev.mysql.com/get/Downloads/MySQLGUITools/mysql-gui-tools-5.0-r17-win32.msi/from/pick2. Install MySQL

Oracle9i introduces the MERGE command. You can execute the inserts and updates operations on a table in an SQL statement at the same time. the MERGE command selects rows from one or more data sources to update or inserting to one or more tables. in

In Oracle Database Operations, if the remark01 field is added to the original table TB_HXL_USER, the default value is 'A'. However, because the data volume of the table is large, fields are directly added to the original table, the execution takes a

DML performance is low. One of the most serious causes is the existence of useless indexes. All SQL insert, update, and delete operations will become slower when they need to modify a large number of indexes when each row of data is changed.Many

Run the exp and imp commands to back up 11 GB of data. When importing 10 Gb of data, an error is thrown: the exported file is not valid, and the header verification fails. The import is not terminated successfully. Today, I encountered this

Db_name: Unique identifier of a database (Oracle database. This expression is sufficient for a single database, but with the popularization of distributed databases composed of multiple databases, this method of Command database creates a certain

How to query Oracle character setsMany people have encountered data import failures due to different character sets. This involves three character sets: one is the character set on the El server side, the other is the character set on the oracle

Archive log is fullORA-00257: How to Handle archiver error. Connect internal only, until freed error1. Log On with the sys userSqlplus sys/pass @ tt as sysdba2. Check the location of the archiv log.SQL> show parameter log_archive_dest;NAME TYPE

ERROR-Agent is blocked. blocked reason is: Agent is out-of-sync with repository today, a host in the oem grid is restarted, causing the AGENT to be inaccessible. The following ERROR is reported in the view detailed log: ERROR-Agent is blocked.

PMON failed to acquirelatch, see PMON dump these two days suddenly found a set of running Oracle 10.2.0.1 for RHEL 5.8x86 _ x64 database shut down very slowly, up to 4 minutes, shutdown immediate after alert. log reports a large number of "PMON

Oracle binary type and big object type basics 1. type differentiation NCLOB stores single-byte character data CLOB stores multi-byte character data BFILE stores the pointer to the binary file in the OS file system, files are not stored in the

[Oracle]-[Create index]-How to create an index and some experiences 1. Read the data of the index key to the cache. If the data is not read to the database Cache, there may be a DB file scatter read write wait event. 2. Sort the data of the index

Oracle Database Audit function audit_trail: parameter settings enable or disable database audit functions: none, osdbdb, extendedxmlxml, extendednote: When the parameter is db, extended, or xml, extended records SQL bind and SQL text clob-type

The dual virtual table dual in oracle is a virtual table used to form the select syntax rule. oracle ensures that there will always be only one record in dual. We can use it to do a lot of things, as shown below: 1. To view the current user, you can

ORA-16047: DGID mismatch between destination setting and target database to solve the DG when the master database two nodes can not upload the log to the slave database [SQL] SQL> select dest_name, status, type, database_mode, protection_mode,

Temporary tablespace groups in oracle are in a temporary tablespace group. You can define many temporary table spaces. A temporary tablespace group contains at least one temporary tablespace, but does not contain the maximum number of temporary

Oracle transaction (one) 1) Transaction processing process 1. First, the client must connect to the server, and the server will assign relevant processes to respond to user request operations. 2. When the server starts to receive user SQL operations,