Oracle

1, the creation of the syntax of the index: CREATE UNIUQE | BITMAP INDEX . On . ( | ASC | DESC, | ASC | DESC,...) Tablespace STORAGE LOGGING | Nologging COMPUTE STATISTICS nocompress | Compress Nosort | REVERSE PARTITION | GLOBAL

1, Clustering factor (Clustering_factor): is the use of B-tree index to the cost of interval scanning is very important factors, reflecting the random degree of data distribution in the table 2, the cluster Factor calculation method:① Scan Index②

The Oracle Optimizer evaluates expressions whenever possible and converts a particular syntax structure to an equivalent structure, and this is because: • Either the resulting expression can have a faster speed than the source expression. • Either

Some time ago, in Ali mother new room pressure test process used in the LR test Oracle, with the DBA (landlords) in Hangzhou netcom New computer room for 1000 users of the pressure simulation test. The entire stress test takes two days. The

Before Oracle executes a SQL, it first analyzes the execution plan of the statement and then executes the execution plan. The execution plan for parsing statements is performed by the optimizer (Optimizer). In different cases, a single SQL may have

Normally, Oracle automatically frees up temporary segment A when it completes a sort operation that uses the temp table space, such as a SELECT statement, create INDEX, and so on. But some of us will encounter the temporary segment has not been

This article describes two of the most common ways to develop Oracle Applications in Visual C + + 6.0: ADO (ActiveX Data Objects, ActiveX database objects) and OCI (Oracle call Interface, Oracle Invoke Interface). Through the design experiment, two

ORACLE10G has a new feature flashback Database that, when you start it, periodically writes the changed chunks to the log file of the flashback log. Note that these logs are not written by the traditional log Writer (LGWR) procedure, but by a new

By using a database backup, the DBA can establish a replica database on the same server or other server. This replica database can have the same name (copy) as the primary database or be different from the primary database name (clone). Oracle's

In most cases, modifications to the primary database will be propagated to the physical standby database and applied without the need for additional operations on the physical standby side, except that, depending on the actual configuration, some

Since Oracle9i, Oracle's external Table technology (Oracle External tables) has been greatly enhanced, with external tables accessing external data enhances the ability of Oracle databases and external data sources to interact with data, for data

Compared to EXPDP, IMPDP and exp, IMP found that the former did not have the Resumable function, the test found that EXPDP and IMPDP automatically used the resumable characteristics C:>EXPDP TEST/TEST@ORCL directory=dir_temp dumpfile=t.dmp tables=t2

A brief introduction to the characteristics of OLTP and OLAP systems A: OLTP and OLAP are the 2 most commonly used systems in our daily production libraries, and simply say that OLTP is a system based on a multiple transaction short time slice, and

You may be running an Oracle 10g Release 2 database server, but supporting some applications may have been written very early. Data tables created prior to Oracle 8i typically have a long data type to store large text. With the introduction of the

As a user of an Oracle database, the export and import two commands are never unfamiliar, as they are the tools we often use for data backup and recovery. However, the Oracle character set problems that occur during the use of these two commands

Absrtact: In this paper, Oracle database and Oracle Application optimization, a comprehensive analysis and research, and put forward some of their own suggestions. 1. Introduction With the advent of the information age, people began to use the

I have used personal oracle+developer2000 to develop some programs, when porting to Oracle for NT, I found some features appear error prompts. The study found that the original user was not able to connect normally. Because alias (alias) is not

I made a simple packaging class, the source code posted for your reference. This program is not rigorously tested and needs further refinement, and the code is tested through the xlc of Vs2005 and Aix. Note: If you need to link in vs2005, you will

1. RESTORE command Although the store command has some secondary targets, its main function is to restore files from the Rman backup to prepare for recovery. The Rman and restore commands are very limited, and they will select the most recent

Default:y Specifies how-Export and Import manage the initial extent for table data. The default, compress=y, causes Export to flag table data for consolidation into one initial extent import. If extent sizes are large (for example, because of the