New SQL Server 6.5 still serves only Windows NT environments
- By David Linthicum
- Jun 24, 1996
SQL Server 6.5 builds on an already-solid database server foundation. But it's still
joined at the hip to Microsoft Windows NT and Open Database Connectivity (ODBC), and it
still lacks support for Unix and other non-Microsoft operating systems.
You can run it not just on Intel but on PowerPC, Alpha and Mips platforms--under NT, of
course--in single and multiprocessing architectures.
The best new feature is the Distributed Transaction Coordinator , which juggles
transactions across more than one physical database and recovers if one goes down while
the other continues to process. The transaction coordinator supports transparent two-phase
commit between databases.
SQL Server 6.5 can replicate to any database that communicates via the ODBC middleware
layer. In other words, Oracle Corp., Sybase Inc. and IBM Corp. DB2 databases could
automatically receive data, images and objects from SQL Server. A database administrator
can set up log-based replication as transactions occur or take snapshots on a schedule.
Like most software today, SQL Server comes Internet-ready. It can distribute
information via Microsoft's Internet Information Server, which will be part of the Windows
NT 4.0 operating system .
SQL Server also is integrated with Exchange Server, Microsoft's message-passing
mechanism. A built-in SQL Mail facility uses Exchange to send and receive e-mail or faxes.
The current trend in database servers is to mix on-line transaction processing (OLTP)
applications with on-line analytical processing (OLAP) in data warehousing applications.
SQL Server's new OLAP query extensions, called Cube and Rollup, allow a single query from
any number of front-end tools to return data aggregates through multiple dimensions. This
is a natural way to analyze data and a good fit for decision-support applications.
More and more multidimensional databases are appearing exclusively for OLAP. However,
SQL Server still stores the data the same way physically, and it can represent data
multidimensionally only through a view.
Besides Cube and Rollup, there's a new "data pipe" for retrieving information
for multiple heterogeneous sources. For example, SQL Server 6.5 could populate SQL Server
tables that serve as a data warehouse or data mart. Again, ODBC is the linking mechanism.
SQL Server supports very large databases and can rebuild their indexes without dropping
or recreating, with point-in-time recovery and the ability to dump and reload specific
There's new remote management support through a version of SQL Enterprise Manager that
uses built-in Simple Network Management Protocol monitoring agents. Also, a Transfer
Manager helps the administrator move data and schemas from one database to another or use
Object Linking and Embedding automation objects for data transfer.
SQL Server 6.5 supports Federal Information Processing Standard 127-2 for Structured
Query Language and the American National Standards Institute's SQL-92. It works with
XA-compliant transaction processing monitors.
Installation is just a matter of running setup.exe from the CD-ROM. During
installation, you must specify whether to license the server per connection or per user.
The default is 20 users, although the software can handle more than 100 users depending on
processors, memory and disk size.
I installed the software on a 90-MHz Pentium PC with 24M of RAM. I followed the
defaults, but you can tune for any environment, adding extra network protocols and
security options during or after installation. Subsystems that install with the core
database server include SQL Security Manager, SQL Client Configuration Utility, SQL Web
Page Wizard and SQL Performance Monitor.
I tested SQL Server 6.5 with several clients--Borland International's Delphi,
Microsoft's Visual Basic and Powersoft's PowerBuilder--all using ODBC. For load testing, I
ran several C++ programs that pushed and pulled data randomly to and from SQL Server.
Although I couldn't simulate an enterprise-level load of 100 concurrent connections, I
did find good performance with the small workgroup-class applications.
If new features get you interested but performance holds you, you'll like SQL Server.
Its multithreaded, parallel database engine supports reduced checkpoint serialization,
faster sort and index operations, and extra counters and ""high-water marks''
for performance monitoring.
SQL Server and NT automatically take advantage of any extra processors present. SQL
Server can equalize the processing load among processors, and you can tune it further for
symmetric multiprocessing by setting such options as SMP concurrency and priority boost.
SMP concurrency controls the number of threads that SQL Server can launch in the
Windows NT environment, which limits the number of CPUs used. The priority boost option
tells SQL Server whether it should run at a higher priority than other processes executing
on the same computer.
I found little wrong with this product--installation was effortless, configuration
easy, performance outstanding and tuning simple. The new replication and World Wide Web
link features add value to a reliable server.
I couldn't crash it, and it recovered without data loss when I accidentally turned off
the computer. Moreover, there's no need to deal with the inner workings of the operating
system, as with other database servers.
But before you buy SQL Server 6.5, remember that it's coupled with Windows NT. You
won't find Unix support, which limits scalability. If you want a server for more operating
systems, you'll be better off with a product from Sybase, Oracle or Informix Software Inc.
Although SQL Server's replication services have advanced, they still depend on ODBC.
It's difficult to customize for resources that don't have ODBC connections.
SQL Server 6.5 will find its audience in the large number of two-tier workgroup
client-server applications for 10 to 100 users. Intel platforms, in single or
multiprocessing incarnations, should work just as well as PowerPC and Alpha.
You can download the software for free, 120-day evaluation from the Web site at http://www.microsoft/com/sql/.
David S. Linthicum, a client-server expert, works with Electronic Data Systems
Corp. on a large Defense Department contract.
Redmond, Wash.; tel.
Price: Server license $999, single client-access license $149
Overall grade: A[--]
[+] Good performance, ease of use and stability
[--] Yoked to Windows NT
[--] Replication only through ODBC
Real-life requirements: Windows NT 3.51 Pentium server with at least 24M RAM
and plenty of hard-drive room; varying requirements for PowerPC, Alpha and Mips servers.