The first thing to think about is how much data the program can handle without going off its nut or slowing down so much that you could walk to Waukeegan and back while your program is processing any entry. Here are some terms and ideas to keep in mind:
◻ The data base, or data file, contains all your entries. InfoStar allows any number of data files per diskette; others allow only one. Score one for InfoStar.
◻ The data record covers all the information you store for each entry into your data base. How big will your program allow each data record to be? How many data records will your program allow before it seizes up and refuses to accept any more? Will the program warn you that as of X moment its files are full and it won’t accept any more records? (I once spent two days trying to figure out why Perfect Filer was giving me back nothing but garbage before I thought to check and see whether my diskette was full.)
InfoStar will allow you a maximum of 65,535 data records per file. By way of comparison, Perfect Filer will accept as many data records as the diskette will hold—about a thousand if your diskettes will hold 200K of memory and you’ve filled up your data entry screen with lots and lots of data fields; probably a skillion if you only have one one-character data field and a lot of disk capacity. The new program dBASE III will allow over a billion records or two billion characters in a file—again, up to the limit of your disk space.
◻ The data fields are the building blocks to your data record. Some obvious attributes a data field may have are that it is alphabetic (letters only); numeric (numbers only); or alphanumeric
(okay, you guessed it). That’s about all the simplest data base programs allow—but here’s where InfoStar is an absolute champ. Some of the attributes InfoStar will allow:
1. The field may only contain certain numbers and/or letters—for example, if you’re typing in a state abbreviation and type “IT” when you mean “IN,” InfoStar will stop you and tell you that’s not acceptable. (It does this by checking what is called an authority file and comparing the authority’s contents with your input. Handy-dandy!)
2. The field will enter itself based on your previous entries. For example, you can enter that your customer wants 47 of your code number W889AA (widgets), two entries; and InfoStar can look up the price of widgets, multiply that by 47, look up the sales tax for the state you inputted earlier, multiply your subtotal by the amount of sales tax, and all by itself enter the name of the product, the subtotal, the amount of the sales tax, and the total—zip-zip-zip-zip, four entries, all done by the computer rather than by you and all done in a flash. The first time I tried it, I was startled into yelling, “Wa-hoo!”
3. The field can be a constant. For example, if your data record contains years, you can tell InfoStar to enter “198” automatically, and you only have to enter “4,” “5,” or whatever.
4. The field can automatically shift cases for you. For example, you can type in “new york, ny,” and InfoStar will insert into the data record “New York, NY.”