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From Suresh Thalamati <tsur...@Source-Zone.org>
Subject Re: Bulk load of large data sets
Date Sat, 15 Jan 2005 01:55:08 GMT

Hi  David,

I briefly looked at the import in code org.apache.derby.impl.load 
package, it does not seem to be designed to keep all the rows that
are being imported in the memory. It  seems to read  one rows at a time 
through BufferedReader() .
I tested  importing 300 MB of data  into emp(id int, name char(100), 
dept char(30)) table.  JVM memory usage is
 < 30 MB. Are you seeing any memory growth when you import smaller set 
of rows like 300MB in your environment ?

It is possible that you might be  hitting some wierd bug ; I doubt any 
one would have tried this case before.
I am interested to debug this problem if  you could provide me the 
following information :

1) Schema of the table (indexes ..etc) ..
2) Few rows of the data that you are importing.
3) All the paremeter you are passing to the IMPORT procedure.
4) what JVM are you using ?
5) parameter that you are passing to jvm like heap size ..etc.
6) Are you doing this in Network Server ot embedded ?
7)Are you executing the import procedure through IJ or a JDBC program ?

David Van Couvering wrote:

>Hi, all.  I get a Java OutOfMemory error when I try to load a large
>table into a derby database using the bulk load stored procedure
>SYSCS_UTIL.SYSCS_IMPORT_TABLE.  It is a 5GB table. It appears that this
>procedure tries to load the entire table into cache before it
>checkpoints it? 
 I don't believe that will be the case.  Page Cache will write the pages 
and reuse them whenever it needs new pages.;
 it does not grow infinitely ,  default should be around 1000 pages.

> Any advice would be much appreciated, I can't allocate
>5GB of memory to Java...
It is possible to that 5GB import to use  more  memory than normal if 
garbage collector is not able to catch up. But
it shoud not require 5GB memory for sure.


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