Oracle

1, what is a cursor? ① retrieves a result set from a table from which the mechanism for interacting with each record is pointed.Operations in the ② relational database are performed on a complete rowset.The rowset returned by the SELECT statement

A package is an attribute of Oracle Pl/sql, which is like a container or a namespace that combines a variety of logically related types, constants, variables, exceptions, and subroutines. Provides a good organizational unit when writing large,

In the large and Medium-sized database management system at home and abroad, there are more users of Oracle as database management platform. Oracle is not only a database management capability or security is justifiable, but it is in the display of

This weekend, when the Lord Bo was in his own Windows host, the Oracle database in the virtual machine was connected with Pl/sql, and there was a problem of approximately more than 10 seconds to log in to succeed. It's a strange phenomenon because I

As a result of project requirements, SQL Server must be converted to Oracle, some SQL Server views using the IsNull function, the following several Oracle functions and IsNull have a similar effect: NVL (EXPR1,EXPR2) If EXPR1 is null, returns the

Oracle Execution PlanRecently has been dealing with Oracle, from the initial face of the confused to now slightly know, also to summarize their recent studies, not regularly updated ing ...One: What is the Oracle execution plan?Execution plan is a

At the Oracle OpenWorld Conference in San Francisco in 2015, Oracle released the beta version of database 12.2, although the beta version is only available to some users, But the conference has unveiled 12.2 of the most important new features, and

The first thing to figure out is the execution plan?An execution plan is a query scheme that the database makes based on the statistics of SQL statements and related tables, which are generated automatically by the query optimizer, such as an SQL

Problem Description:1. Prompt in em openHttps://localhost:1158/em/console/database/instance/repDown?target=orclweng&type=oracle_databaseOra-12505:tns: The listener currently does not recognize the SID given in the connection descriptor (DBD

Using Python to connect to an Oracle database is a hassle, especially under Windows, where the Oracle database is installed by default, and the installation process can be problematic for users who do not want to install Oracle on their machines.

Package Oracle.clob;Import Java.io.BufferedReader;Import Java.io.File;Import Java.io.FileReader;Import java.io.IOException;Import Java.io.Reader;Import Java.io.StringReader;Import java.sql.Connection;Import Java.sql.DriverManager;Import

CREATE OR REPLACE PROCEDURE send_mail (P_recipient VARCHAR2,--Mail RecipientP_subject VARCHAR2,--Mail headerP_message VARCHAR2--Message body)Is--The following four variables should be assigned according to the actual mail serverV_mailhost VARCHAR2 (+

1, ordinary users to modify their own passwordUse the password command to modify the new password for the Scott user name, beginning with a letter, but advocating the use of tigerPassword old password: Tiger new password: abc123 Enter the new

Introduce specific scenariosThere are several issues that need to be migrated from existing Oracle and imported into hive: 1. The existing Oracle database cannot be exported using the entire library, the database server does not have permissions,

First, ASM (Automatic storage management) for the reason:ASM is a new feature introduced in Oracle 10g R2 to simplify the management of Oracle databases, a volume manager provided by Oracle itself, primarily used to replace the LVM provided by the

Operation of the database, often error operation, yesterday after the update operation found that the update is wrong, only to find ways to recover data, now tidy upFirst step: Query the time to perform the update operationSelect from V$sqlarea R

1.1trunc function handles numbersThe TRUNC function returns the processed value, and its working mechanism is very similar to the round function, except that the function does not make the corresponding rounding selection processing of the specified

In this tutorial you'll learn to create horizontal scrollable tabular or detail data block by using stacked canvas in or Acle Forms.As shown in below picture the first column Empno was fixed and middle columns ename, Job, Mgr and HireDate are

The following content to be derived from, just for the convenience of the query reproduced here:Http://www.cnblogs.com/yanxiaodi/p/5038387.htmlAbout a few years ago, I did an Oracle project with Petapoco, and it was cumbersome to install Oracle's

Exadata backup recovery is the same as that of a single machine or RAC database, but there are some optimization best practices for multiple nodes. Today, we will briefly talk about the backup and recovery of Exadata.To fully utilize the I/O