1 Chapters 21, 22, 23, 37  Ch. 21: SQL*Loader  Ch. 22: Database Links, Oracle Net  Ch. 23: Materialized Views (aka Snapshots)  Ch. 37: Data Dictionary

2 Ch. 21: SQL*Loader  SQL*Loader loads data from external files into tables in Oracle.  Usually requires 2 primary files: Datafile(s), data to be loaded. Control file, describes how to load. these two files can be combined into the control file.  When executing, SQL*Loader creates: bad file, shows rejected rows log file, shows load status

3 Ch. 21: SQL*Loader Control File Examples  Variable field control file  Fixed field control file

4 Ch. 22: Database Links  Database links allow you to access data in another Oracle database.  Requires that Oracle Net (aka Oracle SQL*Net or Net8) be running on both database servers.  Links specify: Protocol (eg. TCP/IP) Host name of remote server. Database name on the remote server The database account and password to access the data.

5 Ch. 22: Database Links  Create Database Link syntax: CREATE DATABASE LINK MYLINK CONNECT TO ATEAL IDENTIFIED BY PASSWORD USING ‘PHOENIX’;  Using a database link: SELECT COUNT(*) FROM  Using a synonym with a database link: CREATE SYNONYM MYTABLE FOR SELECT COUNT(*) FROM MYTABLE;  “Dynamic” links using SQL*Plus’s copy command: COPY FROM CREATE NEWTABLECOPY USING SELECT * FROM MYTABLE;

6 Ch. 22: Oracle Net  Oracle Net is Oracle’s networking software. Formerly called SQL*Net (7.x) and Net8 (8.0.x and 8i).  Oracle Net’s local configuration files are sqlnet.ora and tnsnames.ora. These are located in ORACLE_HOME\network\admin.  Example tnsnames.ora entries below. LOCAL = (DESCRIPTION = (SOURCE_ROUTE = OFF) (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = TONYTEAL)(PORT = 1521)) ) (CONNECT_DATA = (SERVICE_NAME = ORACLE) ) PHOENIX = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = phoenix.cs.iupui.edu)(PORT = 1521)) ) (CONNECT_DATA = (SID = OS80) )

7 Ch. 23: Materialized Views  Materialized Views (formerly called Snapshots) pre-aggregate data, index the data, and therefore improve query performance. Oracle creates a table that holds the data that otherwise might be accessed from queries/views.  Materialized views are commonly used in reporting applications.  When you create a materialized view, you must specify: The query the materialized view is based on. The refresh schedule. How the update is performed (update vs. complete refresh) The key type (rowid vs. primary key)

8 Ch. 37: Data Dictionary  Oracle’s Data Dictionary views stores all the information about what is stored in the database.  Three types of data dictionary views: DBA_% views are only available to DBAs (granted DBA role). ALL_% views show all objects the user has privileges on. USER_% views show only objects in your schema.  The Road Map views: DICT and DICT_COLUMNS DICTIONARY (DICT) – describes other dictionary views DICT_COLUMNS – describes columns of DICT views

9 Ch. 37: Data Dictionary  Important Data Dictionary views: USER_TABLES (TABS) – tables USER_TAB_COLUMNS (COLS) – columns of tables USER_VIEWS – views USER_SYNONYMS (SYN) – synonyms USER_SEQUENCES (SEQ) – sequences USER_CONSTRAINTS – constraints USER_CONS_COLUMNS – columns of the constraints USER_INDEXES (IND) – indexes USER_IND_COLUMNS – columns of indexes