Exploring Oracle7 Server for Windows NT

Oracle7 Server for Windows NT has been around for more than two years. In August, Oracle released version7.3.2.2, and it includes improvements that make this popular OnLine TransactionProcessing (OLTP) database server a strong contender in the NT database market.For NT managers and database administrators (DBAs), Release 7.3.2.2 offersimportant new functions, such as built-in symmetric (update-anywhere)replication and the Oracle Enterprise Manager 1.2 database administration tool.

As an OLTP server, Oracle7 Server for NT is made for systems that process ahigh volume of entered transactions (in contrast to client/server, datawarehousing, and decision-support applications all of which focus on retrievingdata). Example OLTP applications include order processing, airline reservations,stock exchange, and retail cash register and inventory systems that typicallyrun on mainframe or UNIX platforms.

Oracle7 Server for NT is available for both NT 3.51 and 4.0 in twoversions: Oracle7 Enterprise Server for NT, a full-featured database server, andOracle7 Workgroup Server for NT, a subset of Enterprise Server's features. Bothversions include Oracle Enterprise Manager for administering your databases, asymmetrical replication manager that uses the flexible update-anywhere model todistribute data, Oracle WebServer for hosting your Web site, and Oracle'sprocedural-language version of SQL (PL/SQL) for creating everything from storedprocedures to custom applications. The main differences between the twoversions, as you see in Table 1, are that Enterprise Server includes upwardscaleability and more options than Workgroup Server. The other difference isthat Oracle doesn't publish prices for Enterprise Server, presumably because thecompany bundles most high-end enterprise sales with several components such astraining and consulting services.

Click-and-Go Installation
I installed a late beta version ofOracle7 Enterprise Server Release 7.3.2.2 under NT 3.51 (Oracle's EnterpriseServer for NT 4.0 wasn't ready at press time) on a 100MHz Intel Pentium with16MB of memory, although Oracle recommends at least 32MB. Oracle also recommendsat least 200MB of disk space for a full install. (I had a previous version ofOracle that I removed before installing the new version, although theinstallation routine can upgrade an existing version.) I was curious to seewhether I could install Oracle7 on a 16MB system. Obviously, I was notworried about performance--especially because I was running beta code. TheEnterprise Server CD-ROM contains more than 7000 files, including:

Despite the product's complexity, installing the software is basicallyclick and go. Oracle makes the necessary Registry entries that autostart OracleServer, so after Oracle finishes installing the files, you only have to rebootNT to get Oracle Server up and running. Installation is easy, whether you'reinstalling Oracle for the first time or the tenth time. The installer asks youwhich components to install. A typical installation takes between 5 minutes and20 minutes, depending on factors such as the speed of your CD-ROM drive and howmany components you install.

After you install Oracle7 Server for NT (including Oracle EnterpriseManager) and reboot NT, the program creates two program groups: Oracle forWindows NT and Oracle Enterprise Manager. Screen 1 shows the Enterprise Manager,which groups all Oracle database administration utilities under one umbrella.

Log On Through Service Manager
You can check whether OracleServer for NT is running by logging on through NT's Server Manager 2.3 (whichusers of previous versions of Oracle will recognize as a visual version of SQL*DBA). Enter the command CONNECT SCOTT/TIGER, and issue a SQL command such asSELECT * FROM EMP to check whether you can access the database.

SCOTT with his TIGER password is just one of many predefined accounts andprivileges. SCOTT is a standard user account with basic connect privileges(logon names and passwords are not case sensitive) for the Oracle starterdatabase, which includes the sample employee (EMP) table. Other predefined useraccounts include:

Click Instance Manager
Another way to verify that Oracle Serveris running is to click the NT Instance Manager icon in the Oracle for NT programgroup or to select the Services icon from NT's Control Panel. You should have atleast three Oracle services running: OracleServiceORCL, OracleStartORCL, andOracleTNS Listener. OracleServiceORCL starts the Oracle service engine, whileOracleStartORCL creates an instance that starts the database. OracleTNSListeneris the mechanism the database uses to listen for incoming connections: A clientcan't connect to a remote server unless the listener is running. You can useNetwork Manager to configure the listener, which is part of SQL*Net, for variousprotocols. At install time, Network Manager can configure the listener toautomatically pull information from the OS and detect any installed protocols.The listener stores this information in the listener.ora file. (You may alsohave to click the SQL Net Easy Installation icon in the Oracle for NT group togenerate the required tnsnames.ora file, a SQL*Net configuration file thatenables a client to connect to a remote server.)

Enterprise Manager
If you're new to Oracle and want a quick viewof Oracle's inner workings, log on to the Oracle Enterprise Manager (a set ofOracle database tables that the logon screen refers to as the repository) assysman with the password sysman. sysman is a special, high-privilege accountthat Oracle provides with the standard starter and replication starterdatabases. This account is primarily for Oracle Enterprise Manager, whichrequires certain tables. Instead of requiring someone with DBA privileges to runa SQL script to create these tables, Oracle lets you sign on as sysman. If youprefer not to use the sysman/sysman account, the documentation providesstep-by-step instructions for setting up the required tables yourself. Whetheror not you use sysman, Oracle recommends that you immediately change alldefault account passwords for security reasons.

Leave the Services field blank and accept the default local connection. Youwill see the Oracle Enterprise Manager console, as in Screen 2.

The Oracle Enterprise Manager console is your starting point for performingmany Oracle Server for NT administrative functions, such as creating databasesand tables or managing user accounts. By default, the console displays fourframes, but you can easily configure the console display to show fewer frames.Oracle redesigned the console in Oracle7 Server for NT 7.3.2.2: It's easier tonavigate and better organized than in earlier releases.

In Screen 2, the upper left pane is the Navigator, which lets you explorethe Databases, Groups, Names, Servers, Nodes, and Parallel Servers folders in afamiliar hierarchical outline format. In the Databases folder, you can use alocal connection such as beq-local.world or tcp-loopback.world to exploreOracle's sample default database. The Job Scheduling and Event Management paneslist jobs and events--if any--associated with the selected database. The Mappane depicts a distributed network.

Although Oracle Enterprise Manager provides excellent online Help, OracleServer for NT (and the overall Oracle7 product) is complex. Because of theproduct's complexity, consider taking one or more classes offered by OracleEducation, a division of Oracle.

Overall Performance
Applications running on Oracle7 Server forNT 7.3.2.2 can take advantage of the program's parallel architecture. You candistribute tasks among up to four processors in Oracle Workgroup Server runningon symmetrical multiprocessing (SMP) systems. (Oracle Enterprise Server'sscaleability is less constrained--it's currently limited by NT's support for upto eight processors.)

Oracle7 already supports parallelization across multiple machines (e.g., ina clustered environment), so expect to see Oracle add cluster support to OracleServer for NT after Microsoft and the major server vendors settle on theWolfpack clustering API that NT will use. Oracle also offers Oracle7 ParallelServer, which supports parallelization across multiple machines. Parallel Serverisn't available for NT yet, but Oracle expects to release an NT version by early1997, which coincides with Microsoft's announced schedule for Wolfpack support.Oracle Server is also scaleable and portable across more than 80 platforms andoperating systems.

Features
Oracle7 Server for NT 7.3.2.2 includes symmetricalreplication, a database administrator (Oracle Enterprise Manager 1.2), and aprocedural-language version of SQL (PL/SQL 2.3). In keeping with the trendtoward online services, Oracle also provides a basic Web server (OracleWebServer 1.0) for serving your database information over the Internet. Let'slook at each feature.

Symmetric Replication
Oracle7 Enterprise Server for NT Release7.3.2.2 is one of two major database servers that ship with symmetricreplication built in (Microsoft's SQL Server 6.5 is the other). Replication isimportant for two reasons: It's great for distributing and for exchanging data.For example, mobile workers can benefit from replication, and you can use it tocreate failover or standby databases. Although Oracle eschews the term symmetricin favor of the less intimidating term advanced, symmetric replication(sometimes called bidirectional, update-anywhere, or peer-to-peer replication)lets you keep databases (or subsets thereof) in synch--either out from a centralsite to mobile workers or in to a central database from the mobile workers.Unidirectional replication (also called master/slave or snapshot replication),in contrast, doesn't permit replication from remote sites. Figure 1 shows amodel for the types of fault-tolerant databases you can create with replication.

If you don't need symmetric replication, you can consider Oracle7 WorkgroupServer for NT. This version supports only the simpler unidirectional replicationmodel.

Oracle Enterprise Manager 1.2
Oracle Enterprise Manager 1.2greatly improves on the database administration features in earlier OracleServer for NT releases. Oracle7's point-and-click graphical interface and OracleEnterprise Manager's central console make old command-line workhorse utilitiessuch as SQL*DBA much more accessible.

Enterprise Manager 1.2's features include

You can add optional functions to Enterprise Manager with Oracle'sPerformance Pack, which provides performance monitoring. A lock manager givesDBAs a graphical and hierarchical view of user and application locks associatedwith the active database. Oracle Trace lets programmers of third-party productswrite to the Oracle Trace API. And Oracle Expert, a rules-based expert system,generates configuration and tuning recommendations according to Oracle7 Serverfor NT performance data.

PL/SQL 2.3
PL/SQL, Oracle's procedural-language version of SQL,lets Oracle developers create stored procedures and triggers that are importantin creating partitioned client/server or Internet and intranet server-centricapplications. For PL/SQL programmers, Oracle7 Server for NT 7.3.2.2 includes newfeatures, such as support for server-side file I/O and the ability to retrievemultirow sets from stored procedures.

Oracle's $3995 Developer/2000 and Designer/2000 tools are graphicaldevelopment tools that generate PL/SQL. New Oracle users will want to explorethese products and the relationship between them.

Oracle WebServer 1.0
Oracle includes a Web server, WebServer1.0, in Oracle7 Server for NT 7.3.2.2, but it's limited to generating HTML viathe Common Gateway Interface (CGI). WebServer 1.0 offers you basic Web serving,but if you want more, check out Oracle's WebServer 3.0, which, according toOracle, will include an improved Web Request Broker. The Oracle Web RequestBroker, a proprietary API that first appeared in WebServer 2.0, is Oracle's CGIalternative that can conduct persistent database transactions. (WebServer 3.0 isexpected in late 1996 or early 1997.)

The upgrade from WebServer 1.0 to WebServer 2.0 isn't free. A license forunlimited access over the Internet costs $5900 per processor for the Oracle7Workgroup Server (Oracle Enterprise Server costs more, but Oracle will notdisclose the price).

A Buffet of Features
Oracle7 Server for NT 7.3.2.2 offers someother noteworthy features, such as

A smorgasbord of new features in Oracle7 Server for NT 7.3.2.2 makes Oraclea strong relational database management system for NT. Long a player in thedata-retrieval application market, NT is finally becoming a platform formission-critical OLTP systems, such as Oracle Server for NT.