Client/Server Computing with Sybase SQL Anywhere

Complete Sybase documentation for Sybase SQL Anywhere (SA) can be found by selecting Sybase Manuals on the Help menu in Office Manager (OM), Case Manager (CM), or Appointment Scheduler (AS). Alternatively, select Start > Programs > SOS Applications > Sybase Manuals. There are actually three SA guides:

SQL Anywhere Server SQL Usage, which includes an introduction to SA databases, queries, and other related topics. Many of these are not relevant to your “read only” access to the SOS database.

SQL Anywhere Server SQL Reference, which includes detailed information about SQL syntax.

SQL Anywhere Server Database Administration, which is perhaps the most useful in that it includes detail about management of the database and log files.

Another valuable source of SA information is the Sybase web site, http://www.sybase.com.

Specifications and Limits

The version of SA that comes with SOS Applications is locked to prevent changes to any SOS data by third party programs such as Microsoft Access. This restriction in no way limits your ability to view, read, report, or analyze SOS data with another program (assuming you have been granted access), but you will not be able to modify the data. Without a thorough knowledge of the intricacies of the SOS database and exactly how the many tables relate to one another, you could accidentally introduce data errors or inconsistencies by making a seemingly innocent change.

As you can see from the specifications below, you are extremely unlikely to run into any technical limitations of the database system.

Database size Operating system maximum file size
Number of tables per database Up to 4 billion
Number of tables referenced per transaction No limit
Table size Limited only by file size
Number of columns per table 45,000
Number of rows per table Limited only by file size
Row size Limited only by table size
Number of rows per database Limited only by file size
Field size 2 GB
Number of indexes 2,048 per table
Maximum index entry size No limit

Standalone Installations

When you run an SOS application in a standalone configuration, you are making use of three separate but related software systems: SOS’s application, Microsoft’s Open Database Connectivity (ODBC) system, and Sybase’s SA personal database server engine.

OM, CM and other SOS programs are called front-end or client applications. These applications do not directly manipulate the data stored in the database files. Rather they sends messages, commands, and requests to the Windows ODBC system. Using information stored in the SA driver installed on your system, ODBC translates these generic messages into the specific dialect that can be understood and acted upon by the SA database engine, also running on your system. The database engine then retrieves or modifies your data in accordance with the messages received through the ODBC interface and passes any requested data back to the client program through the ODBC layer.

Network Installations

Client/Server architecture was designed to make network computing more efficient. Work is divided between client workstations and a powerful server, thereby improving performance. Further, client/server applications create much less “traffic” on the network, also resulting in higher performance. Finally, because workstations do not directly control the physical data files, there is little chance of data corruption from power losses, reboots, and other disruptions at the workstation end of the system.

As with a standalone implementation, the operation of an SOS program involves several related software systems (the front-end program such as OM, CM, or the Appointment Scheduler, the Windows ODBC component, the SA client drivers) but also the network operating system on the workstation, the network operating system on the server computer and the SA server software. The network implementation also involves additional hardware components, including network interface cards, cables, other network devices, and, of course, the server computer itself. In a wide area network installation, there can also be routers, firewalls, and various other pieces of communications technology. If the SOS application has trouble reading or updating data in the database, any of these components could be to blame.

All of these potential points of failure could lead to challenging troubleshooting, but the presence or absence of the same problem at a different workstation can quickly isolate the problem to the server or workstation. See the Troubleshooting document in the SOS web site document library for pointers on problem-solving. The online user group (http://groups.google.com/group/sosoft) also can be a great resource. Another user may have had and solved a similar problem in the past.

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