Oracle

According to Oracle's documentation, the data pump in different ways to export imports, performance can be significantly different, this time just have the opportunity to test, migration table space, direct path, external table, and database chain

Problem one: such as Paugaca JDBC driver: Normally we have three ways to load drivers: 1) class.forname (string) this would like to be a class specified by a String that initializes the static content of the driver at load time, ClassLoader In

In Oracle databases, Undo has three main roles: providing consistent read (consistent read), ROLLBACK TRANSACTION (Rollback Transaction), and instance recovery (Instance Recovery). Consistency reading is relative to dirty read (Dirty read).

Creating triggers The general syntax for creating triggers is: CREATE [OR REPLACE] TRIGGER trigger_name {before | After} {INSERT | DELETE | UPDATE [of column [, Column ...]]} [OR {INSERT | DELETE | UPDATE [of column [, Column ...]]} ...] on

--Logging mode (LOGGING, FORCE LOGGING, nologging) --================================================== First, logging mode (LOGGING, FORCE LOGGING, nologging) 1. Meaning of the three LOGGING: Log information is logged to the online redo log

In the previous section, "Data Guard series (2)-Log Transfer", we introduced the DG Log Transport service, the log Application service is introduced in this section after the log is transferred from the main library to the standby repository, and

1. Variable 2. Constant 3. Basic program Structure and statement Pl/sql can reside in both Oracle database servers and Oracle development tools environments. In both environments, the Pl/sql engine accepts any pl/sql block and subroutine as input,

A view is a table that is exported from a table or view, or a table that is exported from more than one table or view. A view is a virtual table in which the database does not actually store the data that corresponds to the view, only the definition

(1) The basic syntax for creating a table is as follows: CREATE TABLE TableName (columnName dataType [default Expression][column columnstraint],... N) [tablespace Tablespacename] (2) The basic syntax for modifying a table is as follows: ALTER

1. Estimated implementation plan-Explain plans Explain plan takes the SQL statement as input, gets the execution plans for the SQL statement, and stores the execution plan output in the schedule table. First, in front of the SQL statement you want

In the SQL statement optimization process, we often use hint, and now summarize the use of Oracle hint in the SQL optimization process: 1./*+all_rows*/ It is shown that the cost-based optimization method is chosen for the statement block, and the

Recursive calls the number of recursive calls generated by the user or system; DB block gets: The number of times the current chunk of data is requested; Consitent gets gets the number of redo blocks of data from the buffer cache; Physical reads

Two days ago, it was mentioned that the serializable isolation does not support the ability to delay segment creation and interval partitioning, and it is thought that because both of these methods are recursively generating DDL operations in DML,

1. Choose the appropriate Oracle Optimizer There are 3 Oracle optimizer types: A. Rule (rule-based) B. Cost (based on costs) c. CHOOSE (optional). Set the default optimizer to pass various declarations of optimizer_mode parameters in the Init.ora

There are a variety of data stored in the Oracle database, some of which are growing larger over time. such as friends chat log, SMS send and receive log, production system log, dynamic website Publishing system log and so on. This information is

Absrtact: Oracle database is one of the most widely used large-scale databases, and its optimization is directly related to the operation efficiency of the system. Based on the basic principle of database performance optimization, this paper

I use Oracle9i, Oracle8, there is a long time, I put in the JSP need to pay attention to the problem here to write, only for your reference. How to deal with the large types of CLOB and blobs CLOB can be used to store large text data, storing up

Problem:1, at the same time install desktop, engine,engine part of the control can not be used, always prompted to authorize.2, will desktop uninstall, engine most of the controls can be used, a small number of can not be used. Key issues:There is

Oracle's 11GR2 version does not make much of a change to the data pump, mainly by adding support for the original version parameters and removing some small restrictions. This article introduces the improvement of data pump to the table fuzzy

Oracle database transparent Data encryption (TDE), introduced as part of Oracle's Advanced Security options (Version 10.2 and later), selectively enables sensitive database data that remains in the underlying data files of the database and all