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• Table of Contents• Index• Reviews• Reader Reviews• Errata• AcademicOracle Essentials: Oracle Database 10g, 3rd EditionBy
Publisher: O''ReillyPub Date: February 2004ISBN: 0-596-00585-7Pages: 368
This new edition distills a vast amount of knowledge into an
easy-to-read volume covering the full range of Oracle''s
features and technologies. The book includes an overview of
Oracle 10g, along with recent releases 9i and 8i.
Oracle Essentials 3rd Edition: Oracle Database
10g provides everything you''ll need to install
and run the Oracle databases. If you''re new to Oracle or
upgrading to Oracle 10g, you''ll find this comprehensive
guide essential.
2.4 The Data Dictionary
Each Oracle database includes a set of what is called
metadata,
or data that describes the structure of the data contained by the
database including table definitions and integrity constraints. The
tables and views that hold this metadata are referred to as the
Oracle data dictionary. All the components
discussed in this chapter have corresponding system tables and views
in the data dictionary that fully describe the characteristics of the
component. You can query these tables and views using standard SQL
statements. Table 2-1 shows where you can find some of the
information available about each of the components in the data
dictionary.
Component | Data dictionary tables and views |
|---|---|
DatabaseShared server | V$DATABASE, V$VERSION, V$INSTANCEV$QUEUE, V$DISPATCHER, V$SHARED SERVER |
Tablespaces | DBA_TABLESPACES, DBA_DATA_files, DBA_FREE_SPACE |
Control files | V$CONTROLFILE, V$PARAMETER, V$CONTROLFILE_RECORD_SECTION |
Datafiles | V$DATAFILE, V$DATAFILE_HEADER, V$filesTAT, DBA_DATA_files |
Segments | DBA_SEGMENTS |
Extents | DBA_EXTENTS |
Redo threads, groups, and numbers | V$THREAD, V$LOG, V$LOGFILE |
Archiving status | V$DATABASE, V$LOG, V$ARCHIVED_LOG, V$ARCHIVE_DEST |
Database instance | V$INSTANCE, V$PARAMETER, V$SYSTEM_PARAMETER |
Memory structure | V$SGA, V$SGASTAT, V$SGAINFO, V$SGA_DYNAMIC_COMPONENTS, V$SGA_DYNAMIC_FREE_MEMORY, V$SGA_RESIZE_OPS, V$SGA_RESIZE_CURRENT_OPS, V$DB_OBJECT_CACHE, V$SQL, V$SQLTEXT, V$SQLAREA |
Work area memory | V$PGASTAT, V$SYSSTAT, V$SESSTAT |
Processes | V$PROCESS, V$BGPROCESS, V$SESSION, V$LOCK |
RMAN recovery | V$RECOVER_FILE |
User passwords | V$PWFILE_USERS |
Data
dictionary tables that are preceded
by the V$ or GV$ prefixes are dynamic tables, which are continually
updated to reflect the current state of the Oracle database. Static
data dictionary tables can have a prefix such as DBA_, ALL_, or USER_
to indicate the scope of the objects listed in the view.
