Oracle

1) Create a sequence:Create sequence Seq_test--field name MinValue 1--Minimum value MaxValue XXXXX--set maximum start with 1--count from 1 increment by 1          --Add 1 nocycle at a time--always accumulating, not circulating nocache; --Do not

1. Understand PL/SQL package The primary purpose of the package is to use a logical composition-related PL/SQL type, such as record type or collection type, PL/SQL cursor or cursor declaration, and PL/SQL subroutine, and can contain any

#!/bin/bashEcho-e "\n\n*********~~~~~~~~~~~~~~~~~~~~~~~~~~~~date:" ' DATE ' +%y/%m/%d%T ' "~~~~~~~~~~~~~~~~~~~~~~~*********" >>/home/oracle/tablespace.logExport Path=/opt/oracle/1102/db01/bin: $PATHExport

View database lock Select object_name, machine, S.sid, s.serial# from Gv$locked_object L, dba_objects o, gv$session s WHERE l.object  _id = o.object_id and l.session_id = S.sid;  Close a sessionalter system kill session ' 305, 48290 '; Take a look

The functions previously described in Oracle are string processing, date functions, mathematical functions, conversion functions, and so on, and a class of functions are general functions. Mainly include: Nvl,nvl2,Nullif,COALESCE, these functions

1. Overview of the ViewA view is actually a query SQL statement that displays related data in one or more tables or other views. The view uses the results of a query as a table, so the view can be thought of as a stored query or a virtual table.

Recently found a lot of people ask me so directly with the System OS user landing Oracle:1. First open the DOS command window by using administrative identity:Then use the command:/ as SysdbaCan:In fact, this command and the SYS user log on After

Oracle Builds Db-linkTest conditionsTwo serversRemote: ip:192.168.0.18,sid:usertest, User name: usertest, Password: 123456Local: IP:192.168.8.90,SID:WJN, user name: Userwjn, Password: mosquito0Parameter settings1. View the database

Oracle Base Table PartitioningFirst, table partition　　(i) Classification of table partitions1. Range partition (range)2. Hash partition (hash)3. List partition4. Compound partition: Range-Hash (range-hash), Range-list (range-list)　　(b) Scope

1, first need to install a good Oracle database, the machine for Plsql connection database Normal, record the database name2. Installing the Cx_oracle modulePip Install Cx_oracle3. Introduction of modules in PythonImport Cx_oracle as CX4.

Oracle deduplication Data Recovery is divided into two methods:SCN and time stamp two methods of recovery. I. Recovering deleted and committed data through the SCN1. Obtain the SCN number of the current databaseSelect Current_scn from V$database;

The difference between rowID and rownum in 1.oracleIn an Oracle database, each row has an identifier for a unique row, ROWID, where the physical location of the row is stored inside the database. The ROWID is a 18-digit number with base-64 encoding.

Implementation features:Triggers before the data is inserted, checking that the columns in the table with the same properties as the inserted data change the state to false, and then the insert is performed.Solution:CREATE OR REPLACE TRIGGER

Creating a script filevim/home/oracle/script/rmanclear.sh#!/bin/bashDate= ' Date ' +%y-%m-%d "'/u01/app/oracle/product/db/bin/rman Target sys/oracle Crosscheck Archivelog All;Delete noprompt expired archivelog all;Delete noprompt Archivelog until

Set environment variables, create new variables,Set Variable name: Nls_lang, Variable value: Simplified Chinese_china. Zhs16gbkWord brother, or not ah;Reference: http://idata.blog.51cto.com/4581576/1065826/Description of the phenomenon:PL/SQL

In general, these two are used to make two (or more) Table joint query, in is the appearance and the inner table as a hash connection, and exists is the outer loop loop, assuming there is a, B two tables, when used:1. Select * from A where ID in

Modify Host Name[Email protected] ~]# sed-i "s/hostname=localhost.localdomain/hostname=oracledb/"/etc/sysconfig/network[Email protected] ~]# hostname oracledbAdd host name and IP correspondence record[Email protected] ~]# vi/etc/hosts192.168.1.160

1. Software Preparation:centos6.7 (64-bit);ORACLE11GR2 ((Linux x86-64))2, execute the following command to install the relevant package:Yum-y install \Binutils \COMPAT-LIBCAP1 \COMPAT-LIBSTDC++-33 \compat-libstdc++-33*.i686 \Elfutils-libelf-devel

SQL Performance Optimization1. Try not to replace all fields with *2. Upper case performance is higher than lowercase3. In the query, when there are multiple conditions behind the where, the condition that filters out the most data is placed on the

Today, the development said that a test library of the table space is full to clean up, even on the test library to see, it is already using 99.98%.Tablespace_name size_g free_g used_pct------------------------------------------------- --------------