by index

Author :? SHOUG Member-Luo Min, ORACLEACS Senior Consultant, asked questions and demands: "Does your Oracle company have such an automatic SQL statement scanning tool? Using this tool, we can import our application software to eliminate most of the

In this article we will look at the optimization of the order BY statement, before which you need to have a basic understanding of the index, and young men and young men who do not know it can start by looking at the index related articles I wrote

Sublime text compared to the code editor such as Notepad++,ultraedit, its function is even more, with a variety of plug-ins, Sublime text in the actual use has become very handy-of course, if you are not comfortable, Then please write a plugin. And

Drop table test; Select count (*) from test;-- Create a test tableCreate Table Test(ID number (9 ),Nick varchar2 (30)); -- Insert Test DataBeginFor I in 1 .. 100000 LoopInsert into test (ID) values (I );End loop;Commit;End; Select * from test; --

Select Select returns the order of records Zhongxing Communication Chongqing Institute Rempo Wu Yuhong Keywords: SELECT, order, optimize, backup, scan, index Article Summary: When we execute the SELECT statement, the order of the records

Conclusion: I. Six methods for obtaining an execution plan (the detailed steps are described in the remarks section at the beginning of each example ):1. Obtain the explain plan for statement;2. set autotrace on;3. statistics_level = all;4. Use dbms_

Yesterday, an iron buddy asked me for help via QQ and asked if the following SQL statement could be optimized. SQL> set timing onsql> set autotrace onsql> select count (*) rowcount_lhy 2 from swgl_ddjbxx T 3 where T. fzgs_dm = '000000' 4 and (t. lrr_

Drop table test; Select count (*) from test;-- Create a test tableCreate Table Test(ID number (9 ),Nick varchar2 (30)); -- Insert Test DataBeginFor I in 1 .. 100000 LoopInsert into test (ID) values (I );End loop;Commit;End; Select * from test; --

SUBLIMETEXT2 shortcut Key ListSublime text compared to the code editor such as Notepad++,ultraedit, its function is even more, with a variety of plug-ins, Sublime text in the actual use has become very handy-of course, if you are not comfortable,

Sublimetext compared to the Notepad++,ultraedit and the like Code Editor, its function is even more, with a variety of plug-in use, Sublime text in the actual use has become very handy--of course, if you are not comfortable, Then please write a

shortcut Keys function Ctrl+shift+n Open new Sublime Ctrl+shift+w Close Sublime, close all open files Ctrl+shift+t Reopen recently closed files CTRL + N New file

Sublime text compared to the code editor such as Notepad++,ultraedit, its function is even more, with a variety of plug-ins, Sublime text in the actual use has become very handy-of course, if you are not comfortable, Then please write a plugin. And

An Iron Man yesterday asked me for help by QQ, asking if the following SQL can be optimized Sql> set timing on sql> set autotrace in sql> select COUNT (*) Rowcount_lhy 2 from swgl_ddjbxx T 3 where T.FZGS_DM = ' 001085 ' 4 and

A beautiful female DBA wants to learn SQL optimization, and is often confused with me. My favorite beauty. Today, he sent an SQL statement asking me to help you. The execution plan is as follows: Select "A1 ". "code", "A1 ". "device_id", "A1 ".

When it was about to get off work last Friday, Galle sent an SQL select tpc.policy_id, tcm.policy_code, tpf.organ_id, to_char(tpf.insert_time, 'YYYY-MM-DD') As insert_time, tpc.change_id, d.policy_code,

Indexing is the most effective way to improve data querying and is the most difficult technology to master, because proper indexing can increase efficiency by 10,000 times times, and invalid indexes may be a waste of database space, or even greatly

Data | database | index Indexing is the most effective way to improve data querying and is the most difficult technology to master, because proper indexing can increase efficiency by 10,000 times times, and invalid indexes may be a waste of database

oracle| Data | database | index Analysis of the application of index in database Indexing is the most effective way to improve data querying and is the most difficult technology to master, because proper indexing can increase efficiency by 10,00

Indexing is the most effective way to improve data querying and is the most difficult technology to master, because proper indexing can increase efficiency by 10,000 times times, and invalid indexes can be a waste of database space, or even greatly

Reprinted from http://my.oschina.net/xianggao/blog/84179 Author: Old demon   Java constant pool technology The constant pool technology in Java is used to create some objects conveniently and quickly. when an object is required, you can obtain one