We make the web work for you     Oracle9i Database Release 2 An evaluation The general trend for Oracle databases is to include more within the database and to extend the scope of the data management that is offered. However, unlike its major competitors, the emphasis is on implementing new facilities actually within the database per se, rather than as adjuncts to the database. Thus Oracle OLAP, for example, is now implemented as a part of the Oracle database, not as a separate database. While Oracle has been gradually adopting this approach for some time, the second major release of the Oracle9i Database makes this strategy absolutely clear: it is a major differentiating factor compared to its competition. Key findings The introduction of XML DB is a welcome addition. This goes further than any of Oracle’s mainstream competitors in its support for XML and must raise serious doubts about the viability of stand-alone XML database solutions. The performance features in Oracle9i Database Release 2 are impressive. Real Application Clusters is particularly powerful and has been enhanced in the latest release. The advanced partitioning features is impressive. Oracle has gone further than any other vendor in providing content management support directly from the database (though you will need Application Server as well for a complete implementation). In the case of both Microsoft and IBM content management is a totally separate product. With the original release of the Oracle9i Database the company included comparable facilities to both its major rivals in the business intelligence arena. With release 2 of its database Oracle has gone further by embedding OLAP at the database level, together with data mining algorithms, in addition to the ETL (extract, transform and load) capabilities that were already included. One very attractive feature of the Oracle9i Database is the Oracle CM SDK (content management softw are developer’s kit - previously known as the Internet File System. The true significance of this was, arguably, overlooked when it was introduced in the Oracle8i Database release. Now it is clear that it enables a transparent consolidation capability in a particularly attractive manner. It has been significantly enhanced in this release. The introduction of Oracle Streams is another major innovation in this release. Unlike competitive products, it embeds all forms of inter-database and messaging capabilities into a single aspect of the database, rather than requiring multiple products, not all of which have a direct relationship with the database. As a concept, Oracle Streams represents a much simpler approach than that of its rivals. Oracle Data Guard is another enhanced feature of this release. Not only does this have a significant impact on maintaining availability in the event of failure, we also like the way that the standby database can be used for reporting purposes while the operational database remains on line, as well as its ability to take over the running of the database when the main system is down for maintenance. There are large number of ease of use features added in this release, ranging from “advisories” that will help with database tuning to a variety of new self-managing and automated functions. The bottom line Since the introduction of the Oracle9i Database, the product has included pretty much all of the major features that its major competitors have offered. With release 2, Oracle has gone further. It is now clear that Oracle includes a greater range of features than its rivals at least as far as the database itself is concerned. Other vendors may offer comparable capabilities (though this is not always the case) but often these will be separately licensed options. Oracle looks to have a more cohesive and closely integrated product solution. The one feature that Oracle does not espouse is support for federated databases. This is a difference of philosophy. Oracle believes that it makes sense to consolidate databases (not necessarily centralise) w here it is sensible to do so, and it is providing the mechanisms to do so, while continuing to provide robust distributed capability. Product Overview Oracle is pushing the idea that Oracle9i Database is more than a database and is, in fact, part of a complete infrastructure. This w as apparent in the original release of the Oracle9i Database with its tight integration with the Oracle9i Application Server, however this does raise the question of w here the database ends and the Application Server begins, even though you can use third party application server products in conjunction with Oracle9i Database if you prefer. However, the concept of a data management platform is much broader than simply the synthesis of the database and application server and extends to a variety of other features such as the built-in ETL (extract, transform and load) facilities, support for content management and so forth, which one would not normally expect in a pure database environment. This concept has been taken further in the case of Oracle9i Database Release 2, because of the integrated support for Business Intelligence, the introduction of XML DB and Streams, and the extension to the product’s Data Guard facilities, amongst other new features. The comprehensive nature of the Oracle9i Database means that we have to be clear about what exactly we are reviewing here and w hat w e are not. Some options, such as Oracle Spatial, cannot sensibly be distinguished from the database nvironment, and are discussed here. However, complementary products like the Oracle9i Application Server and Oracle Data Mining, which can sensibly considered as stand-alone products, are not considered in this report. Product availability The Oracle9i Database runs on all major platforms and is currently in version 9.2.0.2, which was made generally available in October 2002. It is delivered in three different versions: Oracle9i Database Release 2 Standard Edition which is aimed at workgroup and departmental level applications; Oracle9i Database Release 2 Enterprise Edition, which is aimed at corporate level. Oracle9i Database Release 2 Personal Edition, which supports single user development and deployment. There is one further Oracle9i product, which is Oracle9i Lite. However, this is distinct from the other Oracle9i Database per se, in the sense that it has a separate code base and release cycle. It is a reduced footprint database intended for use by mobile users that are disconnected for most of the time. It is not discussed in detail in this review . This review concentrates upon Oracle9i Database Release 2 Enterprise Edition. For convenience, it is simply referred to here as Oracle9i Database Release 2. It should be noted that there are various optional extensions available for the Enterprise Edition. We have not generally distinguished between these and the core product. As we have noted Oracle Data Mining, which is based on the Darw in product that Oracle acquired w hen it bought Thinking Machines, is not discussed in any detail this report. Suffice it to say that in this release Oracle has embedded algorithms (such as clustering and decision trees) into the database as opposed to requiring a separate server. Similarly, data can be mined in situ (that is, without extracting it from the database). This has a number of significant advantages, most particularly that you can work easily against a full dataset, rather than having to extract the data. Database Engine The truth is that all the leading relational databases have a long history of supporting transactional applications, as w ell as the query processes that complement these environments. For this reason there is little purpose in discussing those features that are common across different vendor’s products and w e shall therefore focus on those elements of Oracle9i Database Release 2 that distinguish it from its competitors. Tuning The Oracle9i Database is based on data blocks and the product supports multiple block sizes and the ability to define sub-caches that relate to each block size. In fact, the product’s caching has been significantly enhanced in this release. Oracle supports two types of cache: one for data and one for SQL. In release 2, the company has introduced dynamic re-sizing for both of these cache types. In the case of the data cache this has to be done by the DBA, although there is an adversary (see below ) that w ill help him to do that. In the case of the SQL cache, re-sizing is automatic. One particularly nice feature is the extended reorganisation and redefinition capabilities that are provided. Put briefly, this allow s you to change any physical attribute of a table online, such as its location, partitions (see below ) or its organisation (heaped or indexed). In addition, all types of logical column changes can be done on line, provided that the primary key is not altered. In Oracle9i Database Release 2, Oracle has introduced a number of enhanced utilities to help to make the database more self-managing. In particular, the company has introduced a number of what it calls “advisories”, which are out-of-the-box additions that not only support tuning and diagnostic tasks but also allow the database administrator to model “w hat-if” scenarios. Advisories may be accessed either via SQL or through Enterprise Manager (see below ) although the latter has ease-of-use benefits because of its graphical display capabilities and the ability to change parameter settings from within Enterprise Manager. As far as tuning is concerned, facilities are provided to help reduce parse times, minimise CPU usage, improve SQL execution times, monitor buffer cache sizes (see illustration) and optimise I/O, amongst others. Also in this release, the database now provides actual operation-level query execution statistics rather than estimated statistics. For obvious reasons this w ill make the identification of expensive SQL statements more precise, as w ell as the ability to highlight the most commonly accessed tables, partitions, indexes and so forth. These can be displayed w ithin Enterprise Manager as “Top Ten” type charts. Partitioning Of all the fundamental database performance and tuning mechanisms it is on partitioning that Oracle has concentrated most. In the Oracle8 Database the company introduced the concept of the database being "partition aw are". In effect, this allow s individual partitions to be treated as if they are tables or indexes in their own right. Thus they can be managed individually, without affecting the w hole table or index. This can have significant performance advantages in a number of respects, for instance w hen bulk loading data, doing back-ups or undertaking recovery procedures. Oracle9i Database Release 2 supports hash, range and list partitioning as primary options. Using hash partitioning results in partitions of equal size. As might be imagined this is nice and simple and is most useful in parallel processing environments. However, management starts to be complex if the number of partitions is subject to change, w hen a range based approach, which is particularly useful for supporting rolling window operations, may be superior. However, this suffers from the fact that partitions w ill be of different sizes and, therefore, is inferior in terms of data distribution. So list partitioning w ill often turn out to be the best form of partitioning from a maintenance point-of-view , though this w ill obviously depend on the data and how it is accessed. Indeed, one of the advantages of Oracle’s approach is precisely that you can tailor partitioning to your environment. One enhancement to list partitioning is that there is now a default partition. This means that application code no longer needs to check that all values fall into the “list”. The very fact that you need to have a choice of approaches to partitioning suggests that none of these is ideal. In order to improve whatever compromises have to be made, Oracle introduced composite range-hash partitioning some time ago, and has now added composite range-list partitioning. In both of these cases data is partitioned by range initially (say, by month) and then sub-partitioned using either a hash technique or by list (for example, based on a geographic region). In the latest release, Oracle has added support for composite range-list partitioning. To support the management of such partitions there are a variety of maintenance operations that w ill let you add, drop, move, rename, split, merge, coalesce, truncate and analyse partitions. Real Application Clusters When parallelism w as first introduced into both database systems and hardware in the last decade, there w as a great debate about the relative merits of shared-nothing and shared-disk systems, at both software and hardware levels. As far as software is concerned the debate went underground somewhat in the late 90s as the emphasis for vendors w as in providing any parallelism at all. However, now that this has been achieved by all the leading vendors (to a greater or lesser extent), the debate has flared up again. Both IBM and Microsoft are advocating federated databases, which suit their shared-nothing approach, while Oracle promotes clustering with a shared-disk architecture. This is not to say that Microsoft and IBM cannot run on clustered systems - they can (although you may have to w rite an application specifically for that purpose, which is not the case with Oracle’s implementation) - or that Oracle cannot support federation (since w hat you share at the hardware level does not have to be w hat you share at the database level, and vice versa). It is simply that Oracle believes that there are more advantages (performance and scalability, removal of data synchronisation issues, and so forth) offered by consolidation and Real Application Clusters than there are from adopting a federated approach. Offshore Oracle database development? Call us. We can do it !             Offshore development – Does it work ?     We are what we repeatedly do. Excellence, then, is not an act, but a habit. Aristotle               © 1999- Digital Mesh Softech India (P) Limited, Kochi. Home | Client Login | Sitemap | Our Land | Privacy | Terms of use