Oracle

In Oracle, table space is the basic method of data management, all users ' objects should be stored in the table space, that is, the user has the right to use the space, in order to create user Object Otherwise it is not allowed to create objects,

In the process of running the database, it is unavoidable to encounter all kinds of situations which can cause the database to be corrupted. For example, sudden power outages, Oracle or operating system bugs caused the internal logical structure of

Data block corruption due to hardware failure or operating system failure during Oracle database operation that causes Oracle to not recognize or contain content in Oracle format Failure, this bad block can be divided into media damage and logical

Products: AIX, Oracle Platform: pseries, AIX Version: All Conflicts in memory access now when the process requests more memory than the total physical memory of the system, in order to handle this situation, the system swaps the program and the

First, users 1, the use of SQL to create the user's syntax format is as follows: Create user user_name--username/ [identified by password | externally | Globally as ' external_name ']--how to authenticate the user , the authentication

The PL/SQL statement provides the ability to process a result set line by row through a cursor. A cursor can be treated as a special pointer that is associated with a query result and can point to any location in the result set to handle the data at

ORA-01555 snapshots are too old to be a common mistake in the database, such as when our transaction needs to use Undo to build the CR block, and the corresponding undo does not exist, this time will report the ORA-01555 error. The ORA-01555 error

SELECT * from Dba_data_files; Col name format A15 Col failgroup format A20 Col path format A30 Oracle kfed and Kfod Tools description 1. Check V$asm_disk.header_status toverify that the disk header was in a ' member ' state. Check the status of

On the itpub see a forall execute update post, feel a little meaning, simple record. Previously studied INSERT statements in ForAll, found that the statement through the binding array, the way to achieve a batch binding, a run of the way, thereby

Because the B*tree index does not store null values, some Oracle queries do not use indexes when the indexed field is allowed to be empty. Most of the time, it appears that we can use a full index scan, which may give Oracle the chance to discard

1. Database version Leo1@leo1>select * from V$version; BANNER -------------------------------------------------------------------------------- Oracle database11g Enterprise Edition release 11.2.0.1.0-64bit Production Pl/sql

First, the theory Source ADD EXTRACT , Tranlog, BEGIN , [, THREADS] ADD exttrail , EXTRACT EDIT PARAMS --Identify the Extract group: EXTRACT --Specify database login information as needed for the database: [Sourcedb ,] [USERID [, PASSWORD

Today to increase the data file, the database file name more than one point, although it can be used, but in the operating system to see the file but feel very uncomfortable, check some data, modify the method summarized as follows: 1. Close the

In an Oracle database system, there are two ways to authenticate users if they want to log on to an Oracle database as a privileged user (Internal/sysdba/sysoper): Using authentication that is integrated with the operating system or using the Oracle

The Pl/sql code in Oracle involves two execution engines, one that specializes in standard SQL statements, and another process code that handles Pl/sql, which typically leads to extra CPU overhead on engine switching. For example, the difference

Today, I learned about the latest popular Ruby on Rails, which is that when a code generator links an Oracle database, it checks for half a day of data. Finally found a way, ^______^. 1. Installation drive http://rubyforge.org/projects/ruby-oci8/

Oracle allows up to 148 enabled when user roles are enabled. In fact, this limit is strange, because 148 and 2 of the power difference is large, do not know what the reason for Oracle to determine this value: Sql> CREATE USER U_role identified by

In 11.2, Oracle optimized the execution plan for all outer joins. In previous releases, the execution plan for the full outer join was as follows: Sql> SELECT * from V$version; BANNER --------------------------------------------------------------

Odp.net 11g is an Oracle-released Ado.net component for. NET programs to access Oracle databases, better performance than Microsoft's own Oracle components, more access to the UDT (User Defined type) type, Procedure, Ref and so on advanced Oracle

Eight Copy Introduction to 8.1 image replicas RMAN can create database data files, archive redo logs, or exact copies of control files. The Rman copy is a copy of these files, and the difference is only in the name and location changes. We don't