TweetFollow Us on Twitter

Jovis, a Database Engine

Volume Number: 14 (1998)
Issue Number: 4
Column Tag: Tools Of The Trade

Jovis, a Database Engine in a Tiny Package

by Edward Ringel

A robust database engine for HyperCard and other XCMD compatible environments

Introduction

Knowledge base development, particularly contract or in-house development, does not require a C, Pascal or C++ environment. To the contrary, many corporate databases and commercially deployed knowledge bases are well supported by database languages such as Fourth Dimension. Other knowledge bases use an authoring front end along with an attached database engine. For example, I use a product called Scientific American Medicine, a complete electronic textbook of internal medicine, that is extensively cross referenced and searchable. It was developed with a MacroMedia Director front end. High level, programmable authoring environments such as HyperCard, SuperCard, and Director can be particularly appropriate when the knowledge base includes pictures, sounds, and videos. These environments are inherently multimedia capable and require little programming knowledge to play a QuickTime clip or show a PICT.

Jovis, by DAS Works, is an extended XFCN that provides broad relational and architectural database capabilities for environments that support XCMD's and XFCN's. This is a comprehensive, well documented product that can support knowledge base development and more traditional database functions in a number of different user settings.

Out of the Box

I received a single disk, a serial number, and a big book. The product comes as a single user SDK or an individually configured Client/Server product; I was sent the single user product for review. In order to use Jovis, I needed to install the product into a HyperCard stack. I could not install the XFCN's into HyperCard itself. Installation, rather than execution is protected by the serial number. (Licensing is addressed later.) The code I used is 68K based and is just under 400K. A PPC version is also available if requested.

The documentation consists of a 16 lesson tutorial and extensive documentation of the various calls. As with most good documentation, the tutorial builds nicely upon itself and is easy to follow. DAS Works does not supply step by step "solutions" to the tutorials; this forces the reader to actually work through the projects to see if they work. The demo supplied with the product actually is a culmination of the tutorials and is a real world example. The lessons address both the relational and architectural capabilities of the product. An introduction also is provided to show some of the intricacies of multi-user issues such as record locking and transactions.

The reference section comprehensively addresses the Jovis calls. Each entry describes the syntax of the call, provides an example, describes the action of the call, and offers relevant comments.

Although a tutorial for Jovis is provided, there is little in the way of more complex examples or a section on "putting it all together." I think they must assume that the user has a good idea of how to use a database. The tutorial teaches the nomenclature and specifics of this particular environment, but does not address design or the management of a complex environment.

The Product

Jovis supports a comprehensive set of relational commands and structures. Relational file creation and open/close operations are very simple and straightforward. Physical files on disk are referred to as "collections," and can contain multiple tables ("relations") and indices. Architectural files are flat file structures that allow the storage, indexing, and rapid retrieval of arbitrary size binary objects (Binary Large Objects, or BLOBs.)

Relation and index construction within a collection requires some work and programming, as with any database system. Jovis offers a shortcut to field and index creation by permitting the creation of a field list or index list. Conceptually, this is like a STR# resource that is then read into the create function, but it is supported as a text string within the scripting language of the front end environment.

Reading and writing records can be performed from script variables or directly into fields in a card or background. Large amounts of data can be read directly into records by an ImportData command. This can be particularly valuable for filling a knowledge base once the structure has been designed and created. There also is an ExportData command.

Obviously, an important feature of a relational engine is the ability to perform a complex search. Jovis does this well. There is a nice section in the tutorial that describes the various comparison operators and how to create compound selection criteria. Jovis supports range searches and the creation of selections. Multiple selections for a given relation are permitted. Merges, which are the same as SQL joins, are supported as a two step process. Selections are first created and then merged. The tutorial completely explains this process.

Record locking and transactions are supported for the multiuser version. There is a section on how the Jovis server works at a file level, but the manual does not teach you how to undertake the design and deployment of a shared, multiuser database system. Calls provided, however, will permit the knowledgeable user to implement a robust, safe multiuser database.

The architectural commands are as important as the relational instructions. Multimedia developers will make heavy use of BLOBs and managing these objects is critical. One very nice feature of Jovis is its ability to embed an architectural file within a relational file, permitting linkage of relational records to architectural indices. As with the relational commands, there is a series of tutorials that teaches the user how to manipulate flat file constructs in the Jovis environment. The tutorial specifically teaches how to use architectural and relational commands and constructs together, which for many developers may be the heart of the product.

Using Jovis

Jovis can be used in any XCMD compatible environment. I tested Jovis in a somewhat older version of HyperCard as well as the current version. It also will run in SuperCard, Director, and Oracle Media Objects. Jovis has an initial startup memory requirement of 512K over and above those of the scripting environment. In some cases, the larger the database the greater the memory requirement.

I found the product difficult to benchmark in a meaningful way. Particularly in a multimedia setting, with various scripting environments and different hardware configurations, any comparison might well be irrelevant to the user/programmer. My overall impression was that performance was more than adequate.

Use of the product requires that the programmer follow some conventions regarding the need for the programmer to create several global variables which would then be for the use of the database engine rather than the stack. One very nice feature of this product is very good error management. In addition to the XFCN managing and communicating errors, it is possible for your script to intercept and handle error conditions as well. The ability to provide more than "plain vanilla" dialogs reporting an error condition with graceful recovery is critical to a commercial product.

It was difficult to pick a representative complete script to give a flavor of how the product is used. In the end, I simply took the first one in the tutorial, demonstrating creation of a relational file:

function CreateNewFile
   global myDB, JovisErrorCode
   --myDB is reserved for exclusive use by Jovis 
   if myDB = empty then
      put "Jovis" into myDB
   --initialize myDB
      get Jovis("CreateCollection", "myDB")
      --all calls to Jovis are in the format get Jovis(),
      --with the first parameter the action selector
      if item 1 of JovisErrorCode = "error" then
         answer JovisErrorCode
         put empty into myDB
         return "false"
      else if item 1 of JovisErrorCode = "Warning" then
         answer JovisErrorCode
         put empty into myDB
         return "false"
      end if
    else
      return "false"
   end if
   return "true"
end CreateNewFile

Here are some other brief examples:

Create a relation named customers in the file myDB:

on CreateDemoRelation
   get Jovis("CreateRelation", "myDB", "Customers")
end CreateDemoRelation

Create an text index of 8 character length named Last_Name in the relation Customers in the file "myDB"

on CreateTextIndex
   get Jovis("CreateIndex", "myDB", "Customers",  
                     "Last_Name", "text", 8)
end CreateTextIndex

Perform a selection searching on Last_Name in our hypothetical Customers database:

on DemoSelect

   ask "Enter last name to set selection to:"
   if the result = "cancel" then exit DemoScript
   put it into Last_Name
   Put "Field Last_Name = ["& Last_Name &"]" into Criteria
   Put "Last_Name, phone, Customer_ID, Account_Start"  
                  into FieldList
   get Jovis("Set Selection", "myDB", "Customers", 
                  fieldList,Criteria)
end DemoSelect

While I have not commented this code, I think the general sense of the steps and syntax is apparent.

Licensing and Costs

This product has a somewhat complex licensing arrangement. The basic price for a single user license (single computer for non-commercial distribution) is $345. Thus, the person creating a database for personal use is spared the expense of a full commercial license. If the database will be used on more than a single computer, an additional fee of $350 is required. This additional fee covers everything from unlimited commercial distribution to simultaneous use of the single user product on a second computer in the same office. Hypothetically, a knowledge base with a HyperCard front end and a Jovis database that sells 1000 copies still only costs you $695 in license fees to DAS Works. Not too shabby.

The server version is more expensive, but again within reason. The basic multiuser package comes with a server and a three user license and costs $435. Each additonal user costs $85. The server product is protected by a hardware ADB lock. Licenses for the commercial distribution of a multiuser product developed with Jovis are handled on a case by case basis.

The Bottom Line

Jovis is a relational and flat file engine that lives in the XCMD world. It has a complete set of relational commands nicely complemented by architectural commands. The two schemes can be used together to create traditional relations supplemented by BLOBs: a perfect combination to implement multimedia presentations. Although difficult to judge, it appears that performance is more than adequate. The pricing scheme has many steps but is fair. Were I developing multimedia on Macintosh, I would give this product serious consideration to implement my work.

It would be very helpful if DAS Works created a "User Manual." The reference manual and tutorial are both quite good. However, once the user is acquainted with the product, he or she will want a document on putting it all together without needing to browse the tutorials again, and something more cohesive than a function call reference. Additionally, Jovis is sufficiently different in structure and nomenclature from SQL that some in depth solutions to complex examples are warranted. Finally, I respectfully suggest a set of text files containing the scripts for each of the tutorials.

Products Reviewed

Jovis Single User SDK version 1.04. DAS Works, Inc. 250 West 104th St, Suite 84. New York, NY 10025-4292. Toll free (800) 972-2483. Fax (212) 663-4503. email to info@dasworks.com or sales@dasworks.com. There is a website at http://www.dasworks.com/.


Ed Ringel is Contributing Editor for product reviews for MacTech Magazine. When he's not working at the computer or enjoying the Maine lakes and woods, he's a respiratory and critical care physician in Waterville, Maine. He can be reached at eringel@mint.net.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Parallels Desktop 13.0.0 - Run Windows a...
Parallels allows you to run Windows and Mac applications side by side. Choose your view to make Windows invisible while still using its applications, or keep the familiar Windows background and... Read more
Mellel 4.0.0 - The word processor for sc...
Mellel is the leading word processor for OS X and has been widely considered the industry standard for long form documents since its inception. Mellel focuses on writers and scholars for technical... Read more
Adobe Muse CC 2017 2017.1.0 - Design and...
Muse CC 2017 is available as part of Adobe Creative Cloud for as little as $14.99/month (or $9.99/month if you're a previous Muse customer). Adobe Muse 2017 enables designers to create websites as... Read more
WhatsApp 0.2.5862 - Desktop client for W...
WhatsApp is the desktop client for WhatsApp Messenger, a cross-platform mobile messaging app which allows you to exchange messages without having to pay for SMS. WhatsApp Messenger is available for... Read more
WhatsApp 0.2.5862 - Desktop client for W...
WhatsApp is the desktop client for WhatsApp Messenger, a cross-platform mobile messaging app which allows you to exchange messages without having to pay for SMS. WhatsApp Messenger is available for... Read more
Things 3.1.3 - Elegant personal task man...
Things is a task management solution that helps to organize your tasks in an elegant and intuitive way. Things combines powerful features with simplicity through the use of tags and its intelligent... Read more
BetterTouchTool 2.292 - Customize Multi-...
BetterTouchTool adds many new, fully customizable gestures to the Magic Mouse, Multi-Touch MacBook trackpad, and Magic Trackpad. These gestures are customizable: Magic Mouse: Pinch in / out (zoom... Read more
Things 3.1.3 - Elegant personal task man...
Things is a task management solution that helps to organize your tasks in an elegant and intuitive way. Things combines powerful features with simplicity through the use of tags and its intelligent... Read more
BetterTouchTool 2.292 - Customize Multi-...
BetterTouchTool adds many new, fully customizable gestures to the Magic Mouse, Multi-Touch MacBook trackpad, and Magic Trackpad. These gestures are customizable: Magic Mouse: Pinch in / out (zoom... Read more
Bookends 12.8.3 - Reference management a...
Bookends is a full-featured bibliography/reference and information-management system for students and professionals. Bookends uses the cloud to sync reference libraries on all the Macs you use.... Read more

KORG iMono/Poly (Music)
KORG iMono/Poly 1.0.0 Device: iOS Universal Category: Music Price: $19.99, Version: 1.0.0 (iTunes) Description: *** Special Sale for a limited time to celebrate the debut of KORG iMono/Poly (33% OFF) until Sep 30! *** Reviving a... | Read more »
Super Phantom Cat 2 beginner's guid...
Super Phantom Cat 2 presents a whole new world of fun platforming challenges and perplexing puzzles. It's a well-designed platformer with a bright, neon aesthetic that brings the genre up to date. [Read more] | Read more »
Shadow Fight 2 Special Edition (Games)
Shadow Fight 2 Special Edition 1.0.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.0 (iTunes) Description: ** New story chapter! **** No Ads! **** No energy! ** The best fighting series on mobile has returned and... | Read more »
4 RPGs like Final Fantasy XV that deserv...
Square Enix announced another Final Fantasy XV spin-off today - Final Fantasy XV Pocket Edition. This mobile, episodic version of the hit RPG gives the game a chibi-fied makeover. The first episode will be free, followed by 9 more premium episodes... | Read more »
Guild sieges and soul gems in latest upd...
Webzen’s MU Origin hit app stores last year, giving fans of fantasy hack-n-slash MMOs like Diablo a new fix to fixate on. This latest update introduces a competitive guild battle, a fresh dungeon challenge, a mini-game and some elemental gems to... | Read more »
Little Red Lie (Games)
Little Red Lie 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: ARE YOU MORE AFRAID OF POVERTY THAN DEATH? Little Red Lie is a narrative-focused, interactive fiction experience that reduces... | Read more »
You can now apply to be Clash of Clans...
Earlier this month, word got out that the Builder, the trusty handiman who tirelessly built every single building inevery singleClash of Clansbase had called it quits. Sick of seeing his work destroyed endless, the Builder has set out for our world... | Read more »
Meshi Quest beginner's guide - how...
Meshi Quest is Square Enix's newest free-to-play release, and it's a real charmer. You start off as the head of a sushi restaurant, upgrading your food and equipment as you serve visitors heaping helpings of your delicious meals. As you progress,... | Read more »
BUST-A-MOVE JOURNEY (Games)
BUST-A-MOVE JOURNEY 1.0.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.0 (iTunes) Description: BUST-A-MOVE Features:- Shoot bubbles and match 3 or more bubbles of the same color to make them pop!- Complete your... | Read more »
The best card combos in Clash Royale
Clash Royale is all about building a deck of units that synergise well. To help you get off to a flying start, we've put together a list of unit combinations that are incredibly effective. Looking for some choice 2v2 combos? Check out our guide. [... | Read more »

Price Scanner via MacPrices.net

Clearance 2016 13-inch MacBook Airs, Apple re...
Apple has Certified Refurbished 2016 13″ MacBook Airs available starting at $809. An Apple one-year warranty is included with each MacBook, and shipping is free: – 13″ 1.6GHz/8GB/128GB MacBook Air: $... Read more
2017 13-inch MacBook Airs on sale for $100 of...
B&H Photo new 2017 13″ MacBook Airs on sale today for $100 off MSRP, starting at $899: – 13″ 1.8GHz/128GB MacBook Air (MQD32LL/A): $899, $100 off MSRP – 13″ 1.8GHz/256GB MacBook Air (MQD42LL/A... Read more
Sale! 13-inch 2.3GHz MacBook Pros for $100 of...
B&H Photo has 13″ 2.3GHz MacBook Pros in stock today and on sale for $100 off MSRP including free shipping plus NY & NJ sales tax only: – 13-inch 2.3GHz/128GB Space Gray MacBook Pro (MPXQ2LL... Read more
2016 MacBook Pros, Apple refurbished, availab...
Apple has Certified Refurbished 2016 15″ and 13″ MacBook Pros available starting at $1189. An Apple one-year warranty is included with each model, and shipping is free: – 15″ 2.7GHz Touch Bar Space... Read more
Apple offers Certified Refurbished iPhone 6s...
Apple has Certified Refurbished unlocked iPhone 6s’s and 6s Plus’s available starting at $449. An Apple one-year warranty is included with each phone, and shipping is free: – 16GB iPhone 6s: $449, $... Read more
Apple offers Certified Refurbished Pencils fo...
Apple has Certified Refurbished Apple Pencils available for $85 including free shipping. Their price is $14 off MSRP, and it’s the lowest price available for a Pencil. Read more
2016 15-inch 2.6GHz Touch Bar MacBook Pro ava...
B&H Photo has clearance 2016 15″ 2.6GHz MacBook Pros in stock today and on sale for $500 off original MSRP. Shipping is free, and B&H charges NY & NJ sales tax only: – 15″ 2.6GHz Touch... Read more
21-inch 2.3GHz iMac on sale for $999, save $1...
Amazon has the new 2017 21″ 2.3GHz iMac (MMQA2LL/A) in stock and on sale for $999.99 including free shipping. Their price is $100 off MSRP, and it’s the lowest price available for this model. Read more
Free Instant Translator 2.0 App For iOS Relea...
Mobile application development company, Neoappz has announced the release and immediate availability of Instant Translator 2.0 for iOS devices. Instant Translator is a user-friendly application which... Read more
2017 15-inch MacBook Pros on sale for $200 of...
Amazon has 2017 15″ MacBook Pros on sale for $200 off MSRP. Shipping is free: – 15″ 2.8GHz MacBook Pro Space Gray: $2199.99, $200 off MSRP – 15″ 2.8GHz MacBook Pro Silver: $2296, $103 off MSRP – 15″... Read more

Jobs Board

Development Operations and Site Reliability E...
Development Operations and Site Reliability Engineer, Apple Payment Gateway Job Number: 57572631 Santa Clara Valley, California, United States Posted: Jul. 27, 2017 Read more
Frameworks Engineering Manager, *Apple* Wat...
Frameworks Engineering Manager, Apple Watch Job Number: 41632321 Santa Clara Valley, California, United States Posted: Jun. 15, 2017 Weekly Hours: 40.00 Job Summary Read more
Development Operations and Site Reliability E...
Development Operations and Site Reliability Engineer, Apple Payment Gateway Job Number: 57572631 Santa Clara Valley, California, United States Posted: Jul. 27, 2017 Read more
Frameworks Engineering Manager, *Apple* Wat...
Frameworks Engineering Manager, Apple Watch Job Number: 41632321 Santa Clara Valley, California, United States Posted: Jun. 15, 2017 Weekly Hours: 40.00 Job Summary Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.