Database Reference
In-Depth Information
2.2.1
Oracle SQL Improvements in Oracle Database 9i
A new data warehousing command called MERGE.
New features for data warehousing such as CUBE and ROLLUP
GROUP BY extensions and the RANK function. These features are
for use in summary and subtotal reports generated with SQL com-
mands.
Columns and constraints can be renamed.
A query of data at a point in time in the past (called a Flashback
query) is enhanced for use within an SQL command rather than
requiring an environmental session change.
A new datatype called TIMESTAMP supports timezone-sensitive
dates and times.
Nearly full support of SQL*Plus features in iSQL*Plus so you can
create Web-based reports.
Support for the ANSI standard JOIN command among other new
ANSI standards.
XML and partitioning enhancements when creating tables and views.
XML functional capability enhancements allowing various new types
of operations on XML datatypes:
XML conditions:
EQUALS_PATH tries to find something in an XML path.
UNDER_PATH finds something within an XML path.
DEPTH and PATH are ancillary functions of
EQUALS_PATH and UNDER_PATH conditions. DEPTH
is the number of levels within a path and PATH is a relative
path specifier.
Note:
An ancillary function is a subordinate part of whatever uses it. For
example, the DEPTH function can only be used with EQUALS_PATH
and is thus ancillary to the EQUALS_PATH function.
XML functions:
DEPTH and PATH (see previous explanation).
Working with XML document objects:
EXTRACTVALUE returns a scalar value from an XML
document object node.
