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From David Leader <d.lea...@bio.gla.ac.uk>
Subject Re: Accessing embedded database in JAR file
Date Wed, 08 Aug 2007 14:07:34 GMT
Ryan wrote:

>I am trying to create a database that is embedded within a JAR file 
>and so far I am not having any luck. Here is what I have done so far 
>(mostly by the "book" from the Derby docs).

A word of warning. I posted on something similar - but not identical 
- about a month ago (I wanted the db in the jar file that had my java 
app - not possible in my hands) - and ended up zipping the db as the 
Derby docs explain how to address a zipped db. It worked ok on a toy 
db, but the real db - derived from a 24Mb mysqldump - ran as slow as 
treacle. Then we discovered that this was because of the time taken 
to uncompress the db. Using the 'naked' db was much faster (and it 
could all still be packaged in as a Mac app, although as yet we 
haven't got it into a Windows .exe).

While I mention this, could I perhaps raise the remaining speed 
problem. I made a Derby database with one table, two fields and two 
tuples (can't get much smaller) and am running it unzipped from a 
java app that has the simplest gui with a menu with the two fields as 
menu items and a text area for results. After the GUI has opened the 
first query takes perhaps five or ten seconds, whereas the subsequent 
ones are 'instantaneous'. Anyone know why?

  David P.Leader, Biochemistry and Molecular Biology
  Davidson Building, University of Glasgow, Glasgow G12 8QQ, UK
  Phone: +44 41 330-5905  http://doolittle.ibls.gla.ac.uk/leader


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