are gaining in popularity and are ex-
Whatever pected to outsell even relational data-
bases by 2003. And OO databases (see
the “OO Database Orientation” sidebar)
are still minor players with solid but
Happened to strictly niche markets. Sales of relational
databases have grown considerably
faster than the sales of OO databases,
and annual worldwide RDBMS revenues
Object-Oriented are now about 50 times larger.
Rick Cattell, distinguished engineer at
Sun Microsystems, indicated, “Object-
oriented databases are doing just ﬁne, and
Databases? the news of their demise is highly exag-
gerated. While their market [share] isn’t
as big, they continue to be used in areas
like CAD (computer-aided design) and
Neal Leavitt telecommunications, where RDBMSs are
not well suited.”
However, said Michael Stonebraker,
chief technology ofﬁcer at Informix and
couple of years ago, industry an ORDBMS proponent and pioneer,
observers touted object-oriented “ODBMSs occupy a small niche market
databases as a technology on the that has no broad appeal. The technology
rise, well suited for the emerg- is in semi-rigor mortis, and ORDBMSs
ing Internet age. will corner the market within ﬁve years.”
They said object-oriented database-
management systems (ODBMSs) would DATABASE MARKETPLACE
soon become the primary database tech- As Figure 1 shows, IDC, a market
nology, supplanting relational database- research ﬁrm, reported global 1999 sales
management systems (RDBMSs), which revenue of $11.1 billion for relational and
were not designed to handle the type of object-relational databases, but only $211
multimedia data frequently found on the million for OO databases. By 2001, IDC
Internet. As further evidence of this, they expects these totals to increase to $15.6
said the growth of intranets signaled a billion and $265 million, respectively.
decline in the use of client-server net- Relational databases are still by far the Through 2004, IDC predicts annual
works, on which most relational data- most widely used databases. Meanwhile, growth rates of 18.2 percent for relational
bases were used. object-relational database-management databases and only 12.5 percent for
Fast-forward to today, and none of systems (ORDBMSs) have added object object-oriented databases. (These ﬁgures
these predictions has come to pass. capabilities to relational databases. They are based on data IDC [http://www.idc.
com] gathered through 5 May 2000 for
Report No. 22542, “Enterprise Database
Relating to Relational Databases Management Systems Market Forecast
A relational database-management examination from multiple perspectives. and Analysis, 2000-2004.”)
system (RDBMS) includes a collection Relational databases are good for
of data items organized as a table, with managing large amounts of structured, OO databases’ niche markets
the columns representing data categories alphanumerical data. For example, com- OO databases have not become major
and the rows representing the data itself. panies use them to maintain records of players in the database market. However,
For example, a table might contain transactions or personnel ﬁles. they do have niche markets, said Larry
information about product orders, with However, relational databases are rigid Alston, chief technology officer of
the columns representing product types, because their only data structure is tables. exCelon (http://www.exceloncorp.com),
customers, dates of sale, and prices. And they work only with limited, simple a provider of e-commerce products and
Users can access data in the order in data types, such as integers, and thus have services, including OO databases.
which it was entered in a table or had trouble handling complex and user- Because OO databases handle complex
reassemble it in many different ways for deﬁned data types, including multimedia. objects particularly well, they can manage
complex data relationships effectively,
OO Database Orientation
An OO database-management system City University in London. With a rela- housing and business-intelligence services
(ODBMS) supports the modeling and tional database, he said, you have to de- for the Hurwitz Group consultancy.
creation of data as objects. Users can compose the aircraft into tables and then For this and other reasons, although
support new media types with OO data- join the tables when you need to recon- OO databases excel at handling some
bases simply by creating new objects. struct the aircraft. data types, they have not become major
With OO databases, the application However, OO databases don’t scale up players in the database market.
and the database use exactly the same to high transaction volumes and user Figure A illustrates the type of archi-
object model. This isn’t the case with counts as well as relational databases, said tecture used in an OO database—in this
relational databases, with which users Philip Russom, director of data ware- case, Objectivity’s distributed ODBMS.
must utilize an object model for the
application and a relational-data model
for the database. Users thus must Client application
develop mapping procedures between
the object and relational models. Page
Language interface server
RDBMS programmers sometimes spend (C, C++, Java, Smalltalk, and SQL++)
more than 25 percent of their coding time
mapping program objects to the database, Disk
Query Object Schema storage
said Carl Olofson, program director of manager manager manager
information and data management soft-
ware for IDC, a market research ﬁrm.
“The result for ODMBSs is less code Transaction server
to develop, reduced development time, manager
and reduced maintenance costs,” said
Doug Barry, executive director of Barry storage
& Associates consultants and also chair Event Storage Network
manager manager manager
and executive director of the Object Data
Management Group (ODMG), an OO Lock
database-standards organization. Posix server
Meanwhile, OO databases are well
suited for use with applications that must
manage complex relationships among
data objects. Figure A. Objectivity’s distributed database demonstrates important differences between
“If you’re modeling a Boeing 747 with relational and OO databases. For example, unlike relational databases, Objectivity’s
an ODBMS, the relationships between database requires an object manager, which directly creates, names, and manipulates
aircraft parts are directly managed [by the objects as required by the client application. Also, Objectivity’s storage manager can handle
database],” said Akmal Chaudhri, a data- clusters of objects of varying sizes. Relational databases’ storage managers are built like
base expert and visiting scholar at The spreadsheets and tend to work best with data elements of similar size and structure.
said Leon Guzenda, chief technology ofﬁ- “Companies in London like J.P. Mor- instruments quickly and easily, which
cer of ODBMS vendor Objectivity. gan, Chase [Manhattan], and Citibank helps companies get these products to
OO databases are thus popular for use are using ODBMS technologies in mod- market quickly.
with artiﬁcial intelligence and CAD/CAM eling financial instruments [such as
(computer-aided design and manufactur- derivatives and bonds],” said Akmal Technical issues
ing) applications, which entail complex Chaudhri, a database expert and visit- Several technical issues have led to OO
data relationships, he said. CAD/CAM ing scholar at The City University in databases’ limited strength in the data-
applications also use multimedia data London. base marketplace.
types, which OO databases work with The companies use object-oriented Object-relational databases. RDBMS
effectively. analysis and design to model these prod- vendors began developing and market-
Meanwhile, Sun’s Cattell said, hospital ucts because object orientation helps ing OR databases in part in response to
patient-care tracking systems use OO effectively capture the instruments’ struc- the perceived threat from OO databases.
databases because they are easier for ture and behavior, Chaudhri said. Object OR databases work via an object layer
medical personnel to work with than orientation also provides mechanisms that sits atop a conventional tabular rela-
relational databases. such as inheritance for modeling new tional engine. Vendors integrate OO fea-
August 2000 17
I n d u s t r y Tr e n d s
Miscellaneous pre- and
25,000 Relational and object-
Revenue (millions of US dollars)
1999 2000 2001 2002 2003 2004
Source: IDC, 2000
Figure 1. IDC, a market research ﬁrm, predicts steady growth for
object-oriented databases and for relational and object-relational data-
bases through 2004. However, IDC predicts that relational and object-
relational databases will continue to dominate the market.
tures into the databases via software modules (such as
Informix’s DataBlades or Oracle’s Cartridges), each designed to
handle video, audio, text, or other types of media. So, in addi-
tion to handling the numerical data generally used in relational
databases, OR databases can handle multimedia data types.
Performance. OO databases can store data sets in their entirety
and thus typically run faster than relational databases, which
must break data sets into parts for storage within tables and then
reassemble them in response to queries.
In addition, said Sun’s Cattell, OO databases can automatically
cache data in the client application’s memory, thereby eliminating
extra calls to the DBMS’s back end and speeding up responses.
And OO databases use optimizers that determine the best way
to use a database’s indices and physical layout to satisfy a query.
However, relational databases have reduced OO databases’
performance advantage with improved optimizers. The opti-
mizers improve ways of ﬁnding information within relational
databases’ tables and indices.
Standardization. Relational databases use the long-established
SQL (Structured Query Language) standard, which has been
adopted by the International Organization for Standardization
(ISO) and the American National Standards Institute (ANSI).
SQL, used for querying and updating a relational database,
serves as a user interface and application Business issues urtwitz’s Russom thinks OO data-
program interface to an RDBMS.
The Object Database Management
Group has developed ODMG standards
“OO systems have not focused on
bread-and-butter traditional business-
data processing applications where
H bases will continue to be used mostly
in niche markets and that their adop-
tion has peaked. “With this impending
for object-database and object-relational- high performance, reliability, and scal- downturn in the ODBMS life cycle, many
mapping products since 1993. ability are crucial,” Stonebraker said. ODBMS vendors are scrambling to de-
However, the Object Database Manage- “This is a large market where relational velop new products or repositioning exist-
ment Group hasn’t promoted ODMG systems excel and have enjoyed wide ing offerings to create new revenue sources
widely within the ODBMS community and adoption.” as revenue from ODBMSs’ slow down.”
needs more vendors on board to make the “Companies are justiﬁably loathe to “Relational vendors realized that
standard an important factor in the indus- scrap such systems for a different tech- objects are important and added them,
try, said Philip Russom, director of data nology, unless it offers a compelling busi- producing OR systems,” Stonebraker
warehousing and business-intelligence ser- ness advantage, which has rarely been said. “However, the failure of OO ven-
vices for the Hurwitz Group consultancy. demonstrated by OO systems,” he said. dors to realize the importance of SQL
For example, he said, the group cre- “As such, relational systems and their OR and the needs of business-data process-
ated an OQL (Object Query Language) descendants continue to be the market ing has hurt them immensely.” ✸
standard, but very few database vendors leaders.”
implemented it. Meanwhile, because relational data- Neal Leavitt is president of Leavitt
“A much bigger problem is that the bases have a much bigger installed base, Communications. Contact him at neal@
vendors behind ODMG represent zero RDBMS vendors have more money and leavcom.com.
billion [dollars] in revenue while the ven- marketing clout than ODBMS vendors.
dors behind SQL . . . represent several And with their bigger installed base, Editor: Lee Garber, Computer, 10662 Los
billion in revenue,” said Informix’s more tools are available for relational Vaqueros Circle, PO Box 3014, Los Alamitos,
Stonebraker. “Hence, it is not a standard databases, for such functions as admin- CA 90720-1314; firstname.lastname@example.org
with critical mass in the marketplace.” istration and Web development.