Oracle

1. Display current user index information (dba_indexes,all_indexes,user_indexes) 03:41:37 sql> Select Index_name,index_type,uniqueness 03:41:49 2 from User_indexes; Index_name Index_type Uniquenes --------------- --------------- ---------

When you activate a constraint using the Enable VALIDATE option, the error message is prompted if the data already exists that does not meet the constraint rule, and the activation constraint fails. The existing data must be corrected at this time,

1, prohibit the restriction 04:55:47 sql> ALTER TABLE t1 disable novalidate constraint; Table altered. 04:55:48 sql> Select Constraint_name,constraint_type,status,table_name from user_constraints 04:56:03 2 where table_name= ' T1 ';

1. View System permissions sql> desc System_privilege_map; Name Null? Type ----------------------------------------------------------------- -------- -------------------------------------- ------ Privilege not NULL number NAME not NULL VARCHAR2

Since Oracle database backups are available in three ways, each with different recovery characteristics, you should integrate database and file system backups, integrate logical and physical backups. First, backup strategy 1. At the operating

I. Data Control statement (DML) section 1.INSERT (Insert the statement into the data sheet) INSERT INTO 表名(字段名1, 字段名2, ……) VALUES ( 值1, 值2, ……); INSERT INTO 表名(字段名1, 字段名2, ……) SELECT 字段名1, 字段名2, …… FROM 另外的表名; field values for string types must

1. Set up Database automatic backup control files, spfile files 2. Every Sunday to do Rman 0-level full-Library backup 3. Daily (excluding Sunday) do Rman 1-level incremental backup 4. Keep a full library backup, incremental backup within one

The highly available systems of 24*7 (some of which are also called 24*7*365) are becoming more and more widely valued and applied because, in the real world, uninterrupted systems represent uninterrupted, voluntary revenue. But How to build and

In the database, the functions of Redo are mainly implemented through 3 components: Redo log Buffer, LGWR background process, and Redo log file (in archive mode, Redo log files will eventually be written as archive logs). In Oracle's SGA, there is

The concept of a sequence: A sequence is a database object that can be used to generate a unique integer. The main code value is generated automatically by using a sequence. The value of a sequence is automatically generated by a special Oracle

In an Oracle database, creating an index is relatively straightforward. However, it is more difficult to create indexes reasonably. The author believes that when creating an index, it is three appropriate to create an appropriate number of indexes

In Oracle databases, a set of default user operating environments is provided. The number of rows fetched from the database once, such as when a user queries, the separator between columns, the maximum width per line, the number of rows by default

Before running the example of this article, record the INSERT, delete, update, and so on of the current datasheet, and make a backup of the date of operation, the operator, the original data, and now the data so that you can recover from the current

The last time you talked about installing Oracle under Linux, you can use NETAC to configure the local naming of remote databases after installation. To connect Oracle databases under Perl, you must first install DBI and DBD for Oracle. Here's a

In a RAC environment, logging into an instance can result in a GC global wait generation when the data being processed is completely unrelated to the data in the other instance's memory. This article describes the performance impact. The previous

Oracle provides the Wrap tool to encrypt stored procedures, and in 10g this operation can already be done in the database. Oracle's DBMS_DDL adds a wrap function that allows you to return the encrypted process: Sql> Select Dbms_ddl.wrap (' CREATE

ASM supports not only the RAC environment, but also the single node environment. It has always been thought that a single node ASM also needs Clusterware support, and that in this case, starting ASM needs to be configured as a RAC one node approach.

The Rman Page command allows users to determine the current recoverable state of the database and to provide specific information about the database backup. 1. Specify data files that have not been backed up recently The query does not have a

AWR snap generation, not necessarily to generate reports on the original database, you can use AWR provided by the export, import functions, the AWR data migration to the test database for further analysis. AWR's export is not complicated, and

An attempt to import awr data on the test database caused a ORA-4031 error. The error message is: Sql> @?/rdbms/admin/awrload ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~