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Spatial

The Spatial option enables you to store, manage, index, and analyze maps, drawings, and other spatial data in the database. You can use this option to construct applications that query on physical location. You also can use the Spatial option to manage large inventories of parts in different physical locations, or for more advanced querying facilities. You can construct fuzzy queries such as this one:

 Show me the car tire suppliers within 3 miles of London who also have a discount for corporate customers 

Advanced Replication

The Advanced Replication option enables you to have updateable snapshots at two or more sites, with the server ensuring that changes are propagated between two or more sites.

A Customers table could be replicated at five other sites, for example, each of which could update the customer rows. Changes to the rows then would be propagated to each of the other sites automatically at intervals defined by the user .

The Advanced Replication option provides facilities for detecting update conflicts ”for example, when the same row is updated at the same time at two or more sites. In addition, a Replication Manager tool is included to make the management of snapshots easier.

Objects

The Objects option in Oracle8 provides an evolutionary step toward an object-oriented database. This option enables you to define objects and methods in the database that map to real-world objects being modeled by the system.

User-defined abstract datatypes (ADTs) are treated in the same manner as the built-in datatypes. These ADTs enable you to define a customer datatype that includes the customer name , address, and so on, for example, which then can be used in the definition of an orders object. These objects then become the building blocks from which the application system is developed.

In addition, the Objects option enables you to define object views, which enable users to view and process existing relational tables as though they were defined as objects in the database.

TIP

You can use the v$version view, which is accessible to the system user, to see which versions of the Oracle product you have installed. In addition, the v$compatseg view shows you which version of the Oracle server software introduced some of the new releases.

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Installation Preparation

The actual process of installing the Oracle software and creating the first database is relatively easy on most platforms because you can follow the menu options. Preparation before the actual install pays dividends in the long run, though.

One of the first things to consider is the amount of disk space required both for the software and for the database. In addition, you should carefully consider the locations of the program files, database files, redo logs, and control files to avoid disk contention (waiting caused by too much activity on disks).

The amount of storage required for the software varies from platform to platform. The Oracle Installation and User's Guide for your platform should give you an idea of the amount of storage required.

The amount of memory required for Oracle consists of the following:

• Memory required for the Oracle software to load (much of which is reentrant code that can be used at the same time by more than one process)
• Common memory areas (such as the SGA, shared global area)
• Private memory areas (such as the PGA, program global area, for each connection to the database)
• Memory for the client programs executing

However, the front-end tools may be on a different machine than the one on which the database server is being run.

The default memory allocations ( especially for the common SGA area) are not sufficient for most databases.

In addition, some operating system-specific issues need to be addressed (such as the number of semaphore sets in UNIX), most of which are covered in the Installation and User's Guide.

Installing the Software

Most platforms have a menu-driven installation script or, even better, an installation program that makes the installation a one-stop , point-and-click operation, such as the program for installing the Oracle software on the Microsoft Windows platform. Because dependencies exist between different components of the Oracle software, the menu first prompts for the components of software to be installed and works out the dependencies between the various components so that all required components are installed.

On some platforms, you may need to create an operating system account (usually called Oracle) with a high level of privileges that will be used to install the software.

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The operations of connecting as the Oracle user internal, starting up the instance, shutting down the instance, and creating a database are all privileged operations. You can perform all these operations from within the Instance Manager tool (or from the Server Manager tool). As a result, your operating system account must have the necessary operating system privileges to perform these operations (UNIX groups on UNIX or process rights on DEC VAX VMS, for example). The way in which Oracle determines whether these privileges are in effect varies from platform to platform.

At the time of this writing, there is no way to verify that you have installed only the products for which you are licensed, or to stop you from exceeding the number of users for whom you purchased the license.

TIP

Use the v$license view to determine whether you are exceeding the number of users for which you're licensed.

Other Optional Components

When the database software is installed, the installer has the option to install the Oracle server documentation onto the hard disk. If this option is chosen , the manuals can be accessed directly without having to have the product CD in a CD-ROM drive. The software documentation can take over 50MB of hard disk storage.

Another option that the user is presented with is the ability to install Programmer/2000. This installs a product to allow the user to develop 3GL programs with a mixture of SQL and PL/SQL inside a 3GL (third-generation language) program. After SQL and PL/SQL code have been written inside the 3GL program, the Oracle pre-compilers are used to convert the SQL and PL/SQL code into 3GL subroutine calls producing an program entirely in a 3GL language. This program can then be compiled, linked, and run.

Another optional component includes the installation of Oracle intelligent agents. Intelligent agents allow administration of a many remote databases (each with the Intelligent Agent software installed) from a single console running Enterprise Manager. Any database administration requests from the remote console are managed by the Intelligent Agents on the remote database.

The Intelligent Agent software will listen for and process requests for database administration tasks (such as shutting down and starting up the database), and can detect and sometimes resolve errors. The Intelligent Agent software allows tasks to be scheduled at some future point in time, such as a request to start up the database or shut it down at scheduled intervals.

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