Re: [luciddb-users] LucidDB for Spatial OLAP

[John V. S. <js...@gm...>]

Emily Gouge wrote:
> The select query results in a Java Out of Memory Error:
> 
> 0: jdbc:luciddb:rmi://localhost> select count(*) from 
> habc_extraction_schema.master_grid;
> 
> Error: java.lang.OutOfMemoryError: Java heap space (state=,code=0)

Ah, I wonder if it could have anything to do with this?

http://mail-archives.apache.org/mod_mbox/db-ojb-user/200504.mbox/%3C4...@ap...%3E
http://postgis.refractions.net/pipermail/postgis-users/2005-August/008875.html

We may need to add something to the JDBC foreign data wrapper to allow 
control over the fetch size to prevent the PostgreSQL JDBC driver from 
effectively leaking per-row.  Sigh.

As a workaround, you could try loading the data in large chunks of rows 
via a WHERE clause on some partitioning key (if there is one in the 
source data).

Another clunky alternative is to dump the data from PostgreSQL into a 
csv file and load via LucidDB's flatfile reader.  There have recently 
been some problem reports about trying to loading the TPC-H 10gig 
dataset via flatfiles due to a bug in the flatfile reader causing it to 
go into an infinite loop, so it depends whether you're attempting to 
load your full data set or a smaller test set.

JVS