|Oracle9i OLAP Developer's Guide to the OLAP DML
Release 2 (9.2)
Part Number A95298-01
Oracle9i Release 2 provides the OLAP data manipulation language (DML) for multidimensional analysis within the Oracle database. With the OLAP option installed, you can execute DML commands for manipulating data in an analytic workspace. Users of Oracle Express Server release 6.3 will find that there are some new and changed features in the OLAP DML.
The following section describes the new features in Oracle9i OLAP:
The following list briefly describes the new features of the OLAP DML.
Because the OLAP engine runs in the Oracle kernel and analytic workspaces are stored in relational tables, there is no separate file that stores an analytic workspace. This change is reflected in new names and new functionality for existing DML commands.
XCA, SNAPI, and ODBC connections are no longer supported, and the related commands have been removed. Note that session sharing is not supported in the new access methods.
UPDATE command moves changes from a temporary area to the dataase table in which the workspace is stored. The changes are not saved until you execute a
COMMIT command, either from the OLAP DML or from SQL.
Virtual dimension members can be defined at runtime using the new
AGGREGATION command within a
MODEL object. The
AGGREGATE function then calculates data for the custom aggregate the same as any other aggregate.
MODEL command in an aggregation map executes a model either as a data maintenance step (using the
AGGREGATE command) or at runtime (using the
ALLOCATE command provides support for planning applications, such as enterprise budgeting and demand planning systems, which need to allocate data to lower levels of a hierarchy based on sophisticated allocation rules.
IMPORT command loads fact data into workspace objects more quickly than an
PREPARE command includes new options that you can use to specify direct-path insertion of analytic workspace data into relational tables.
In defining a concat dimension, you can combine the values of two or more dimensions into one dimension. You can use a concat dimension to map multidimensional structures to relational schemas and thereby improve data loading from relational sources. You can also use concat dimensions in performing custom aggregations and other customized operations.
The Oracle OLAP DML has a new
NUMBER data type that is the equivalent of the
NUMBER data type in the relational database. You can define a
NUMBER dimension that has
NUMBER values. Oracle OLAP always interprets the values of a
NUMBER dimension as dimension values and not as ordinal position values. You can use a
NUMBER dimension to represent a series of unique numeric values, such as a surrogate key column in a relational database table.
A dimension surrogate is a new type of DML object. You define a dimension surrogate based on a dimension, but the surrogate can be of a different data type than its dimension. The surrogate has the same number of positions as the dimension. You assign values to a surrogate as you would to a variable. You can use a
NUMBER dimension and a dimension surrogate to load surrogate key values from a relational database into an analytic workspace, and then use those key values to load data from the relational fact table or tables into multidimensional structures.
In OLAP DML commands, you can specify an object using its qualified object name, which includes not only the name of the object but also the name of the analytic workspace in which the object resides.
In OLAP DML commands, you can specify an analytic workspace that is in another user's shema by using the full name of the workspace. The full name includes the schema name.
Workspace aliases allow you to reference an analytic workspace using a name that is easier to type than its full name. Aliases also let you write generic code that includes a reference to a workspace but does not hard-code its name.
When you read from or write to a disk file using the OLAP DML, you do not directly specify the directory in which the file resides. Instead, you specify a directory alias that has been set up for your use by the Oracle database administrator.
NTEXT values are encoded in the UTF8 Unicode transformation format.
Oracle OLAP no longer has a configuration setting that specifies the default character set. The Oracle OLAP default is the same as the databse character set.
All Oracle OLAP NLS settings (such as
NLS_LANGUAGE) reflect the session-wide NLS parameter settings. If you set the NLS options in Oracle OLAP, you change your session-wide NLS parameter settings.
The values of these options always mirror the current session-wide NLS parameter settings. You cannot change these settings by changing the values of the Oracle OLAP options.
To be compatible with Oracle database conventions, Oracle OLAP does not provide direct access to system-level information and commands. Therefore, the
SYSINFO function has fewer keywords, and commands such as
SHELL have been removed. In addition, EXTCALL objects are no longer supported.
Because analytic workspaces are stored in database tables, in-place variable storage is no longer applicable.
You cannot use the
WATCH commands for interactive debugging in OLAP Worksheet, but you can use
DBGOUTFILE to record the progress of your programs and models.
DGCART command and function as well as the
CACHETRIES options have been removed. However, you can use OLAP dynamic performance views to monitor performance.
FCSET command allows for multi-cycle periodicity in the forcasts created with
STRIP command has been removed. Use the
HIDE command instead. In previous releases, programs were stripped of their definitions in an analytic workspace file before it was delivered as part of an application. Thus, only compiled code was delivered. Now, analytic workspaces are delivered as EIF files, which contain only definitions and cannot contain compiled code. In this new context, stripped programs would not be executable.