Oracle

Necessary component InstallationActivePython python Windows Support components Unix-like systems have their own Python components download "Baidu ActivePython"oracle_client Oracle Database Link Component "Cannot link to database if not

In Oracle, you can control which IPs can connect to the database and which IP cannot connect to the database. In 9i and later, simply set the allowed IP and banned IP, modify Sqlnet.ora is the best and fastest method1. Modify the Sqlnet.ora fileIn

 1. Using Oracle to compress BLOB objectsL_blob: = utl_compress.lz_compress (L_blob);2. Convert BLOBs to ClobFUNCTION Blob_to_clob (blob_in inch BLOB) RETURN CLOB 

Transferred from:http://chenxy.blog.51cto.com/729966/1684591, the same point a. You can delete data, where truncate is used for full table emptying data, and delete can choose to delete 2, different points: A. rollback, delete supports the rollback

Oracle can use the GET command to read the file contents into a buffer,The syntax for using the GET command is as follows:Get [file] file_name {list|nolist]Where file_name indicates that an external file is specified, and the contents of the file

A database transaction is a unit operation that either succeeds or fails all of the operations. In Oracle, a transaction starts with the execution of the first Data Manipulation language (DML) statement until a commit statement is executed, commits

Logically:Single column indexConcatenated multi-column indexUnique Unique indexNonunique Non-Unique indexfunction-based Function IndexDomain IndexPhysically:Partitioned Partition Indexnonpartitioned Non-partitioned indexesB-tree:Normal B-TreeRever

Oracle iterative query with background menu as an exampleThis is the SQL to be prepared1 Create TableTbl_menu (2Id Number Primary Key,3parent_id Number default 0,4Namevarchar2( -) not NULL,5 direntions Clob,6 Info1 Clob,7 Info2 Clob,8 Info3 Clob9

Database query statement internal execution procedureSELECT * FROM tableStepsAnalysis Phase (parse)1. Shared pool cache There is no such statement. If there is a direct return result.2. Parsing the SQL statement correctly for the next step.3, check

Entity Framework6 with Oracle (can implement code first)Oracle and 2 months ago provided support for EF6. Previously only supported to EF5. EF6 has many useful features that are worth upgrading. Here's how to support OracleI. Oracle provides some

There was a script that ran for a long time without results, and the results were instantly optimized. The original statement is as follows:sql> explain plan for 2 select * 3 from Crm_dg.tb_ba_channelstaff A, 4 crm_dg.tb_ba_s Ubscription_hist B, 5

Oracle creates database graphics decomposition:1. Select All Programs->oracle-oradb11g_home1->configuration and migration ToolsThe Database Configuration Assistant, as shown in:2. Step 1 appears as shown, click Step.3. For example, select Create a

/* divided into four steps *//* 1th step: Create a temporary tablespace */create temporary tablespace user_temp tempfile ' D:\oracle\oradata\Oracle9i\user_ TEMP.DBF ' size 50m autoextend on next 50m maxsize 20480m extent management local; /* 2

Use of packages in OracleUse in Oracle The main purpose of using a package is to modularize the program. The package can combine the relevant stored procedures, functions, variables, constants, cursors, and other PL/SQL programs, in this way, code

ORACLE11GDataGuard role conversion1. ORACLE login uard Role SwitchingDataGuard已经是现今标准的主流容灾方案，由于日志传递对于网络适应程度强，且可以采用同步实时的传递方式和异步延迟的传递方式，甚至可以成为远程的异地容灾方案。不管用于何种用途，DG都免不了要进行角色转换，即将standby 数据库切换为primary数据库，角色转换分为：switchover和failover两种2. similarities and

Oracle10gLsnrctl does not reflect that the database cannot be connectedSymptom Description: The oracle version used is 10.2.0.1.0 in linux. If lsnrctl status is entered on the command line interface, no response is returned. If lsnrctl stop is

Oracle Redo, oracleredo Redo logIn Oracle databases, there is a log file called redo log file, which is commonly known as redolog. There are two types of redolog: Online redo logs and archived logs.ONLINE Redo log Online redo log is mainly used

The functions and disadvantages of database indexes and the advantages of database Indexes Why create an index? This is because creating an index can greatly improve the system performance.First, you can create a unique index to ensure the

Differences between Oracle Data Pump export and traditional export It is estimated that many of my friends are not clear about the differences between Oracle Data Pump export and traditional export. The following small series will introduce you to

Using the DBMS_CRYPTO package in oracle to encrypt sensitive fields in the table Next, let's take a look at how to encrypt table sensitive fields through the DBMS_CRYPTO package in oracle. If you need to know, let's take a look.   As security is