All this talk about DataBases

[J. Landman Gay]

Scott Kane wrote:
> I'd be curious to know why RR decided to 
> change the behaviour of how stacks are read (from file as opposed to 
> loaded fully into RAM). 

They didn't; the engine has always worked that way since its original 
MetaCard incarnation. Scott Raney, the creator, wanted speed and so 
wrote the engine to load everything into RAM. The trade-off is that you 
need as much RAM as the size of your stack -- which is one reason why a 
dedicated database is more suitable for huge data sets.

Raney's standard suggestion was that databases larger than 5,000 cards 
should be moved to a "real" external database. Stacks under that number 
perform acceptably well. I have pushed it to 10,000 or so without any 
particular indexing or special efforts, but it does slow down, 
especially if you use the "find" command to locate content. HyperCard 
had its wickedly fast "hint bits" search that Rev doesn't have. When Rev 
searches, it has to look through the text of every field which is much 
slower. However, if you create an index and the scripts reference cards 
by ID (the fastest way) you can increase the number of cards without too 
much lag.

I wrote a database with over 40,000 records, and for that one I loaded a 
text file into RAM and then used a 1-card display stack to show the 
desired record. This method requires that you write all your own 
navigation and search handlers, but it was about as fast as HC when I 
was done.

-- 
Jacqueline Landman Gay         |     jacque at hyperactivesw.com
HyperActive Software           |     http://www.hyperactivesw.com