Oracle

Analyze table tablename compute statistics; Analyze index indexname compute statistics;   It is very beneficial to use CBO, and more reliable table information can be used, so that the execution plan can be more accurate. In 10 Gb, analyze

D:/Oracle/product/10.2.0/db_1/Network/admin Modify the tnsnames. ora file and add the name of the Oracle instance to be accessed.Funodb_ysf =(Description =(Address = (Protocol = TCP) (host = yangshifeng) (Port = 1521 ))(CONNECT_DATA =(Server =

How to Use PLSQL developer to import and export data from an Oracle database There are three ways to export table data using PL/SQL developer: Oracle export, SQL insert, PL/SQL developer The table structure and index structure remain unchanged

This article uses a simple example to illustrate how to write a ruby script to perform Oracle database operations. The main steps are as follows: 1. Download Ruby at the following address: Http://www.ruby-lang.org/zh_CN/downloads/Here we

  There are five main types of loops: exit when, loop, while, for (Common loop), and for (cursor loop). The following is an example to illustrate (all stored procedures ). 1. Exit when loop:Create or replace procedure proc_test_exit_when isI

Oracle SQL optimization notes Notes for writing Basic SQL statements Use the in operator as few as possible. Basically, all in operators can be replaced by exists. You can use not exists or external join + instead of the not in operator. When

Today, the user requires that all data 0 cannot be involved in the average calculation. The idea is that the AVG function itself does not participate in the calculation of NULL data. Therefore, you only need to convert zero data to null, I thought

When lgwr is idle, it depends on the rdbms rpc message wait event and is in sleep state until three seconds. If lgwr finds that redo information needs to be written, then lgwr will execute the write operation, and the log file parallel write wait

What is a flashback recovery zone? Oracle 10g has a new feature called automatic disk-based backup and recovery ). The basis for implementing this function is the flash recovery area described in this article ). Flash recovery zone is a new feature

A user-defined function is a code block stored in a database. It can return the value to the calling program. The call is like a system function, such as a max (value) function. value is called a parameter. There are three types of function

Someone asked how to determine the day of the week? Select to_char (sysdate, 'D') from dual Obviously, this sentence cannot complete the required function, because it only shows the day of the current week, while foreigners regard Sunday as the

Oracle Data Import and Export dmp 1: Start-> Run-> cmd-> exp-> User Name/password @ connection word (DBA permission is required for full Database Export)-> press ENTER-> enter the export path (C: /AA. DMP)-> select (E, U or T) as required-> press

  I. Official Website description Owid: a globally unique address for a row in a database. Rowid can be divided into extended rowid and restricted rowid. 1.1 restricted rowid Internally, the rowid is a structure that holds information that the

Oracle Advanced Replication supports both full-table-based replication and partial-table-based replication. These two replication schemes are mainly implemented through two replication mechanisms of Oracle, namely multi-master replication and

Include the SQL statement in select (...) from dual. Logic description: Currency + header opening date associated exchange rate maintenance (original currency code, effective date range), get conversion rate, Then, the amount is converted to the

There are two main methods to develop the Oracle database interface in Visual C ++. One method is to use multiple database access technologies provided by Visual C ++, for example, Open Database Connection ODBC, Data Access Object Dao, object

　 1. There are two ways to run Oracle databases: (1) archivelog: Archive aims to restore the database to the maximum extent when a database fails. It ensures that no submitted data is lost: (2) Non-archive mode (noarchivelog): Only the database can

1. If you have a certain database foundation and know what SQL is going on, you can skip to 2 even if you cannot write simple SQL statements but can understand them. Otherwise, let's take a look at the basic database and the SQL language. You don't

The Oracle client of any current version cannot be installed properly on Windows 7 of any version. This is mainly because the operating system version does not meet the requirements for Oracle Installation. However, you can modify refhost. XML to

I. Syntax:Translate (string, from_str, to_str)Ii. Purpose Replace each character in from_str with a string after the corresponding character in to_str. Translate Is a superset of the functions provided by replace. If from_str is longer than