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From Steven Buschman <sbu...@buschman.org>
Subject res.updateXXX
Date Mon, 29 Nov 2004 22:42:13 GMT
Hello,

First let me apologize in advance if I'm not following protocol - this 
is the first time I've accessed an Apache project, so newbie I am.

I downloaded the compiled 56458 release successfully. My intention was 
to port a MySQL client application to Derby, primarily because of the 
near zero admin issues with Derby. After a bit of grief (there are quite 
a few differences), I'm down to just one problem that I can't figure out 
worked w/MySQL 4.1 and fails with Derby:

Statement  state =  
connection.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, 
ResultSet.CONCUR_UPDATABLE);
ResultSet  res     = state.executeQuery("select * from xxx where ...");

if (!res.next())
   throw new Exception(...); // I'm sure the select will succeed!

res.updateString(...); // SQLException occurs !!!! SHOULD NOT HAPPEN!!!
res.updateInt(...);
res.updateRow();
res.close();
state.close();

On a separate note - a few issues that I observed:
1. Using ij, INSERT into table values (..), (...), (...) generates a 
stack overflow if there are too many inserts. I wanted to import 12,000 
rows in Derby and it failed after a dozen rows or so. I was stuck doing 
12,000 separate inserts, which took close to 2 minutes on a very fast 
machine (10K WD drive with 1 GB ram and AMD 64 939).

2. After doing a "select * from table" with 6000 rows and 47 columns, it 
took 10 seconds to load the table if I used res.getXXX("text") but only 
1.5 seconds if I used res.getXXX(integer value).

3. Derby: var INT NOT NULL GENERATED ALWAYS AS IDENTITY vs. MySQL: var 
INT NOT NULL AUTO_INCREMENT
My problem is that Derby won't let me assign a value to var even if it's 
unique. The problem here is that if you're importing data from elsewhere 
and "var" is being used as a foreign key in another table, then it's a 
major pain to make sure everything is in sync.

All in all Derby is fantastic - never have I been able to download and 
port (99%) in just 1 day. I see tremendous opportunities for it for 
small scale applications.

Thanks.

-- 
Steve Buschman
22 Blackburnian Rd.
Lincoln, MA  01773
781-259-0295


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