Database Reference
In-Depth Information
, SALE_QTY
NUMBER
, SHIPPING_COST
FLOAT
, CONSTRAINT
XPKSALESIOT PRIMARY KEY (SALES_ID))
ORGANIZATION INDEX;
INSERT INTO SALESIOT SELECT * FROM SALES;
An IOT is a single table, organized in the order of a BTree index. In
other words, the data space columns are added into the index structure leaf
blocks of a binary tree. An IOT is effectively a BTree table where the entire
table is the index. The same block space is occupied by both data and index
values.
18.3.5
Creating External Tables
An external table is read-only data stored externally to or outside the logical
structure of an Oracle database, at the operating system level. Figure 18.11
shows a syntax diagram containing syntax details relevant to creating exter-
nal tables.
Let's create an external version of the data warehouse SALES table. The
first thing we have to do is create a directory object.
CREATE OR REPLACE DIRECTORY DATA AS 'c:\oracle\ora10\oltp\
data';
Figure 18.11
CREATE TABLE
Syntax for External
Tables.
