Look beneath the covers of your R/3 systems, the SAP Knowledge Warehouse,
or SAP's CRM, B2B, and SCM solutions, and there you will find the SAP
DB relational database management system. It serves not only as an RDBMS,
but also as liveCache in the SAP APO Supply Chain Management solution,
as a database option for Requisite's BugsEye search engine in SAP Business-
to-Business Procurement, and as the Content Server and Content Server
Cache in the SAP Knowledge Warehouse.
While SAP DB is not a household word, I
suspect it soon will be. This proven, powerful, reliable, and scalable
database management system (DBMS) is now available, free-of-charge and
free-of-license-fee, as an open-source database management system. So,
in addition to being used in SAP solutions, you can now use SAP DB for
your non-SAP systems as well.
As of October 2000, SAP DB was made available
to system administrators and developers, as a professional relational
database system. The latest release, SAP DB 7.3, has been available since
April 2001. You can get it, along with source code and documentation,
on the SAP web site at www.sapdb.org
or order the free CD-ROM version from SAP.
When compared to proprietary databases,
SAP DB's open model promotes a more streamlined DBMS. As a portable system,
it is designed to provide all of the standard functionality required,
but without the unnecessary "features" and complexity that often
burden proprietary systems - and in fact can actually inhibit manageability
Although the reduced DBMS complexity of
SAP DB is intended to promote greater ease of use and reduce demand on
system resources, that's not to say that SAP DB is a bare-bones database
management system -
just the opposite. System administrators will also find:
- Automated design decisions, exception handling, and database maintenance
- An easy-to-use interface (DBMGUI)
- An innovative approach that combines full, standard SQL database functionality
combined with object management system features
What's more, the latest version introduces
new browser-based frontend tools. And with SAP DB, there are also no reorganization
requirements, because there is no fragmentation of secondary storage structures.1
But the most important benefits are the
low cost of ownership and the ability
to use a single database management system across all your applications
- not just SAP. And with the program and source code freely available,
SAP's own Basis development team and the entire Open Source community
will be involved in continually enhancing SAP DB.
Automatic Management and Reorganization Features
With SAP DB's automatic memory management features, administrators do
not waste time constantly monitoring the size of tables or reorganizing
the database. Instead, steps that would normally be checked manually are
now performed automatically.
For example, if database recovery is necessary,
a precise proposal for reconstructing the system is generated from the
backup logs. The user is notified automatically about this proposal when
choosing to recover the database. Then the administrating user simply
confirms the proposal, and the system executes it. (The only other manual
operation is inserting or changing tapes or other media!) Of course, the
user also can decide to follow other possible recovery paths by selecting
incremental backup instead of logs. Point-in-time recovery is supported
The database can be scaled easily using
its own process and thread management (internal tasking) functions and
is suitable for both large and small database configurations, regardless
of number of users.
SAP DB Features at a Glance
In 1997, SAP procured the technology (last developed by SQL Datenbanksysteme
GmbH, a subsidiary of Software AG) in an effort to develop the product
further and to ensure support for customers who ran SAP solutions
on ADABAS D. Since 1997, these features have been added to SAP DB:
- Optimized checkpoint handling
- Parallel create index
- Parallel backup and restore
- Online backup without impact on overall performance
- Assisted restore process
- Optimized locking and logging
- Improved handling of log full or database
- Reduced converter cache size (this cache now needs factor 10
- Improved monitoring and diagnostics
- 64-bit Unix platforms
- Linux as additional platform, as of Release 7.2
- NT-based database tools, as of Release 7.2
- Unicode support (UTF-16), as of Release 7.3
- New browser-based database tools with Release 7.
DBMGUI: SAP DB's Easy-to-Use Interface
The SAP DB interface makes management easy. With the special graphic
user interface (DBMGUI), shown in Figure 1, it is possible to manage
multiple SAP DB installations from a single workstation or screen.
||The DBMGUI User Interface for SAP DB
From the Database Manager, the user has
an at-a-glance overview of the database A73, along with specific user-selected
information. The top right window offers an overview of the current state
of each of the registered databases with a few key supervision areas:
data size, log size, and major hit ratios. In the window below, which
displays the selection path and the database name (Info-Data-A73), you
can view information you have selected through the menus to the left,
which offer various specialized areas of supervision and maintenance.
In this example, the administrator is looking for information about the
data devspaces for database A73.
SAP DB's Optimal Approach: Both OMS and RDBMS
Another differentiator is SAP DB's hybrid approach: SAP DB is designed
as both an object management system (OMS) and a relational database management
system (RDBMS). This hybrid database system and the functional "intersections"
that result - such as "SQL class" and "OMS class"
- make it possible to access either OMS data or SQL data through C++ application
To enable SAP DB to operate efficiently
in a complex data model with a relatively large volume of data, SAP added
a main-memory-focused object management system to SAP DB back with Release
7.1. This addition made it possible to store C++ data structures (pointer
structures, such as trees or networks) and enabled several users to navigate
to those structures and change them at the same time. The result is increased
speed, up to at least 50 times higher than if SQL tables had been used
for modeling and navigation (and in some cases, it takes less than 10
microseconds to navigate to an object). Using this approach, SAP DB offers
potential for special database technology when operated in conjunction
with SAP applications, which means that it can be optimized for certain
SAP's liveCache is an example of the potential
of SAP DB's dual approach (see Figure 2).
||SAP DB: A Hybrid Database Management System Supporting Object
Management Sustem (OMS) and SQL Approaches
liveCache is an instance of the SAP DB
designed specifically to handle planning problems with vast amounts of
data, first applied in modules in SAP's Supply Chain Management solution.
SAP designed it for extremely fast, data-intensive functions to leverage
very large, main-memory (64-bit) hardware architecture. liveCache is an
instance of SAP DB that is started only as one specific instance type.
Objects in liveCache are managed by means of transactions and can, if
required, be stored as persistent objects, depending on the application.
Figure 2 highlights some of the
benefits of this approach. The ABAP application layer with its database
interface resides on the application server, and communicates with liveCache
through TCP/IP to exchange packets. liveCache allows functional packages
of an application to be defined as C++ methods of a COM object. Those
objects must be available on the liveCache server as libraries (DLL).
Their methods are made available to the liveCache through a registration
process, and afterward can be called as database procedures. The libraries
are linked to the liveCache kernel at runtime and are executed directly
in the liveCache address space.
Because liveCache is based on
SAP DB's hybrid technology, access to data is provided in one of two ways:
- Instances of C++ classes (OMS Class) or their data elements respectively
can be read from the database (OMS Basis) to the address space of the
method, or vice versa (i.e., elements can be written to the database).
- SQL commands to access relational schemas (SQL Basis) can be transmitted
to the database as a method of the SQL C++ Class (SQL Class).
SAP DB Technical Guidelines
Binary versions of SAP DB are available for these operating systems:
- IBM AIX
- Compaq Tru64
- Windows NT
Database interfaces supported include ODBC (3.5.1), JDBC (2.0),
and a connection to script languages such as Perl, Phython, and
PHP. Windows-based tools such as Database Manager and SQL Studio
are used for administration and database SQL access, and are accompanied
by the browser-based variants Web DBM and Web SQL.
All SAP DB source code will be released
in accordance with GNU Public License (GPL, LGPL) regulations. For
Linux users, SAP DB will be made available through software distributors,
including SuSE. All subsequent versions of the SAP DB will also
be made available in real time to the open source community during
the development phase.
Download, Development, and Support
To obtain your own copy of SAP DB, you can either download it from www.sapdb.org
or order the CD-ROM version. (The current CD, material number 50048324,
contains SAP DB 7.3 and is available free of charge.)
For more information on SAP DB and ordering
the CD version, or to download packages directly, visit www.sapdb.org.
This site provides a wide range of information, software downloads (with
the option of setting up a model database using a script), documentation,
and programming examples.
Information is also available from the
two mailing lists set up by SAP:
SAP DB can be used in SAP applications
without incurring license fees. When SAP DB is used in conjunction with
SAP applications, support is provided by SAP's regular support infrastructure.
Customers who wish to use SAP DB "outside"
of an SAP solution can receive support from a range of software vendors
and application service providers (ASPs) who have many years' experience
with SAP DB and its predecessors. For users of SAP DB outside of SAP applications,
free online support is available through the sapdb-general mailing list.
(This is regarded more as a self-help option, but can also be used to
Advanced customers, software vendors, and
ASPs can receive high-level, comprehensive support by setting up a customer
competence center for SAP DB and purchasing a Premier Support Contract
from SAP. This contract offers full access to the SAP service and support
landscape, such as the OSS Online Service System and SAP Service Marketplace
customer access. For those organizations that already run SAP solutions
on SAP DB, the Premier Support Contract fee will be reduced by the value
of the customer's current SAP DB maintenance fee.
No matter whether you're a developer interested
in open source database management program, or an SAP customer looking
for a single database system to support your SAP and non-SAP programs
alike, SAP DB provides a freely available, scalable, tested relational
database management system to meet your needs.
Jürg Hoffmeister is a
product manager for SAP DB in the SAP Labs Berlin. He is also in charge
of software production and development support. He has been working on
the database since 1985 and has extensive experience in database integration
and database development.
1 For a full
list of SAP DB features, see "SAP DB Features at a Glance" above.