使用數(shù)據(jù)庫(kù)字典和動(dòng)態(tài)性能視圖.ppt

1、使用數(shù)據(jù)庫(kù)字典和動(dòng)態(tài)性能視圖,目標(biāo),學(xué)完這個(gè)課程，你應(yīng)該可以掌握你下內(nèi)容: 區(qū)別內(nèi)置的數(shù)據(jù)庫(kù)對(duì)象 區(qū)別數(shù)據(jù)字典的內(nèi)容和用法 理解數(shù)據(jù)字典視圖是如何創(chuàng)建的 區(qū)別數(shù)據(jù)字典視圖的種類(lèi) 查詢數(shù)據(jù)字典和動(dòng)態(tài)性能視圖 理解administrative script 命名規(guī)則,內(nèi)置的數(shù)據(jù)庫(kù)對(duì)象,Other objects created with the database: Data Dictionary Performance tables PL/SQL packages Database event triggers,Data Dictionary,Central to every Oracle dat

2、abase Describes the database and its objects Contains read-only tables and views Stored in the SYSTEM tablespace Owned by the user SYS Maintained by the Oracle server Accessed with SELECT,Control files,Data files,Redo Log files,Database,Data Dictionarytables,Base Tables and Data Dictionary Views,The

3、 data dictionary contains two parts: Base tables Stores description of the database Created with CREATE DATABASE Data dictionary views Used to simplify the base table information Accessed through public synonyms Created with the catalog.sql script,Creating Data Dictionary Views,ScriptPurpose catalog

4、.sql Creates commonly used data dictionaryviews and synonyms catproc.sqlRuns scripts required for server-sidePL/SQL,Data Dictionary Contents,The data dictionary provides information about: Logical and physical database structures Definitions and space allocations of objects Integrity constraints Use

5、rs Roles Privileges Auditing,How the Data Dictionary is Used,Primary uses: Oracle server uses it to find information about: Users Schema objects Storage structures Oracle server modifies it when a DDL statement is executed. Users and DBAs use it as a read-only reference for information about the dat

6、abase.,Data Dictionary View Categories,Three sets of static views Distinguished by their scope: DBA: What is in all the schemas ALL: What the user can access USER: What is in the users schema,USER_xxx Objects owned by the current user,ALL_xxx Objects accessible by the current user,DBA_xxx All of the

7、 objects in the database,Data Dictionary Examples,General Overview DICTIONARY, DICT_COLUMNS Schema objects DBA_TABLES, DBA_INDEXES, DBA_TAB_COLUMNS, DBA_CONSTRAINTS Space allocation DBA_SEGMENTS, DBA_EXTENTS Database structure DBA_TABLESPACES, DBA_DATA_FILES,Dynamic Performance Tables,Virtual tables

8、 Record current database activity Continually updated while the database is operational Information is accessed from memory and control file Used to monitor and tune the database Owned by SYS user Synonyms begin with V$ Listed in V$FIXED_TABLE,Dynamic Performance Table Examples,V$CONTROLFILE V$DATAB

9、ASE V$DATAFILE V$INSTANCE V$PARAMETER V$SESSION V$SGA $SPPARAMETER V$TABLESPACE V$THREAD V$VERSION,Administrative Scripts Naming Conventions,Summary,In this lesson, you should have learned how to: Identify built-in database objects Identify the contents and uses of the data dictionary Understand how data dictionary views are created Identify data dictionary view categories Query the data dictionary and dynamic performance views Understand administrative script naming convention