I have seen many professionals toting powerful laptops with full enterprise-level RDBMSes installed in order to run a data-driven sales, marketing, or even financial application while they are away from the office. IT shops have long complained about the cost and maintenance associated with these setups, thus database vendors have retooled their database engines specifically for the mobile set.
Sybase is no exception -- providing SQL Anywhere as a suitable solution for quite some time. Now Adaptive Server Anywhere (ASA) 6.0 takes this very capable mobile database even further down the road to simple mobile data access.
ASA comes in a bundle called SQL Anywhere Studio 6.0, which includes other tools such as SQL Modeler for designing databases, Sybase Central for administering them, and InfoMaker for reporting from the database. What makes this version of ASA intriguing and unique is that it can run the server on Windows CE devices and can port database applications to even smaller devices, such as Palm units and pagers using UltraLite technology. ASA also allows users to synchronise their mobile devices with the central corporate database.
Getting a database and related applications onto a laptop is no longer a challenge -- beefy notebooks can now hold more than 100MB of RAM and hard disks in excess of 10Gbytes. However, WinCE devices hold only 16MB of memory at best, and that doesn't begin to address PalmPilots, pagers, and the latest mobile phones. Enterprise-class databases such as Sybase's Adaptive Server Enterprise, IBM's DB2, or Oracle8 -- plus the actual data and application to interact with the data -- have little chance of running on these devices.
I tested ASA on two Pentium-class desktops and connected them to a Sharp Mobilon Pro that runs WinCE. When I installed ASA on the first of the desktops, it asked me whether I wanted to install it on the Mobilon, which it noticed was connected to the desktop. The ASA database engine on WinCE weighed in at a scant 1.8MB, leaving plenty of room for the data and other user files.
The primary benefit of placing a database on a machine such as the Mobilon is that field users can have a copy of the corporate database in their hands when they are out with customers and vendors and need to look up products, prices, orders, and so on -- taking the parts of the database that pertain to them. This low-memory engine makes it possible.
The process of defining mobile users and their set of data belongs to a database administrator, who uses the Sybase Central database administration tool to create a Publication. After defining the Publication, administrators must then create special Remote User IDs for each user (the mobile device) and tie the User IDs to the Publications the users need. Sybase Central provides easy-to-use wizards to aid setup.
The end result of user setup tasks is a SQL script that is run to create the extract data set. The process is somewhat tedious the first time, but having an easily modifiable script makes deploying this to many users easier. By default, ASA automates generating and sending the extract to the mobile device via the use of WinCE's synchronisation.
Once I got my database onto the Mobilon, I made a few modifications to the data. All the manual work I had done to get the data on the Mobilon -- such as creating files and directories -- allowed the updates to go back to the central database almost automatically. DB Remote, which runs on the remote machine, packages the updates into a file that is sent to the central PC for posting. The central and remote machines use asynchronous messaging to exchange the update files.
Sybase has developed UltraLite to allow very low memory devices to use the database. After an application has been built, the UltraLite Analyzer is run to create a very small executable that contains the application code including SQL, as well as a very small footprint database server. The Analyzer includes only features of the database server that are needed by the application and the embedded SQL in the executable along with the code.
MobiLink is used to synchronise an UltraLite application on a remote machine by putting a synchronisation server between the device and the central database. A developer must write scripts for users to indicate what data to synchronise with the device, and the MobiLink server uses these to pass on information. The developer must add a function to the interface to request synchronisation.
Although the database engine for my WinCE-based Mobilon utilised 1.8MB by itself, the application -- database server and all -- was only 99KB with UltraLite.
I could also control the database server that ran on the Mobilon from another PC by using Sybase Central. But I had a difficult time setting this up, primarily because of problems with TCP/IP that IT shops may or may not experience. After setup, I was able to view and manage the remote server as if it were local.
Sybase's Adaptive Server Anywhere is a competent RDBMS, and at $399 it is reasonably priced for what it offers. Add in the bundled applications and support for remote users on machines with very little memory, and it is definitely worth a look for shops using any relational database, especially Sybase.
Jay Tyo (firstname.lastname@example.org) is an application development consultant based in Charleston, South Carolina.
The bottom line: very good
Sybase Adaptive Server Anywhere 6.0
Summary: Companies using Sybase as their relational database of choice with a large remote work force relying on it will find Adaptive Server Anywhere 6.0 (ASA) up to the task.
Business Case: ASA can save you hardware costs by allowing you to outfit remote workers with less-expensive mobile devices instead of costly laptops.
+ Full-featured relational database for PCs, handhelds, and PalmPilots+ Manages remote machines from a central PC+ Ultralite applications exceptionally smallCons- Some setup issues related to TCP/IP configurationCost: $US399 for single user, $999 for five users.
Platforms: Server: Windows 3.x, Windows 95/98, Windows NT 3.51 or later, OS/2, NetWare, Unix (Sun, IBM, HP), remotely on Windows CE. Ultralite: Windows CE, Palm Computing, Symbian EPOCH32, RIM Interactive Pager, Research in Motion Blackberry Mobile Email, MS-DOC, QNX Neutrino, WindRiver VxWorksSybase: www.sybase.com