mysql index 的建立/使用 , Multiple-Column Indexes
http://dev.mysql.com/doc/refman/5.0/en/multiple-column-indexes.html
CREATE TABLE test ( id INT NOT NULL, last_name CHAR(30) NOT NULL, first_name CHAR(30) NOT NULL, PRIMARY KEY (id), INDEX name (last_name,first_name) );
The name
index is an index over the last_name
and first_name
columns. The index can be used for queries that specify values in a known range for last_name
, or for both last_name
and first_name
. Therefore, the name
index is used in the following queries:
SELECT * FROM test WHERE last_name='Widenius'; SELECT * FROM test WHERE last_name='Widenius' AND first_name='Michael'; SELECT * FROM test WHERE last_name='Widenius' AND (first_name='Michael' OR first_name='Monty'); SELECT * FROM test WHERE last_name='Widenius' AND first_name >='M' AND first_name < 'N';
However, the name
index is not used in the following queries, 以下的 query 用不到 index —> 多重 index 有先後區別.
SELECT * FROM test WHERE first_name='Michael'; SELECT * FROM test WHERE last_name='Widenius' OR first_name='Michael';
Manage Oracle Streams Advanced Queuing – DBMS_AQADM
官網資料 : http://download-west.oracle.com/docs/cd/B19306_01/appdev.102/b14258/d_aqadm.htm#i1015375
The DBMS_AQADM
package provides procedures to manage Oracle Streams Advanced Queuing (AQ) configuration and administration information.
See Also:
-
Chapter 185, "Oracle Streams AQ TYPEs" for information about the
TYPE
s to use withDBMS_AQADM
This chapter contains the following topics:
-
-
Constants
-
-
-
Queue Table Subprograms
-
Privilege Subprograms
-
Queue Subprograms
-
Subscriber Subprograms
-
Notification Subprograms
-
Propagation Subprograms
-
Oracle Streams AQ Agent Subprograms
-
Alias Subprograms
-