Oracle Database Express Edition (XE)

To start off with, I'm not exactly a master of oracle databases, so excuse me if I'm just doing something plain stupid.

That being said, our issue.

We are trying out XE as a replacement for a mysql database we use to store semi-real time information. The size of the database doesn't really grow, it's about 600mb and we just constantly overwrite the same records.

We just started running into problems with the 4gb limit, and I'm not sure how, or where the space is going.

Going back through posts about the same error, I tried the SQL people mentioned to see what's going on. And that only confused me further.

Output is below:

SQL> select Sum(bytes)/1024/1024||' MB' as total_size from dba_data_files;

TOTAL_SIZE
-------------------------------------------
810 MB

SQL> select Sum(bytes)/1024/1024||' MB' as free_size from dba_free_space;

FREE_SIZE
-------------------------------------------
171.9375 MB

SQL> select Sum(bytes)/1024/1024||' MB' as used_size from dba_segments;

USED_SIZE
-------------------------------------------
637.8125 MB

SQL> select owner,sum(bytes)/1024/1024||' MB' from dba_segments group by owner;

OWNER SUM(BYTES)/1024/1024||'MB'
------------------------------ -------------------------------------------
TSMSYS .25 MB
FLOWS_020100 78.8125 MB
OUTLN .5 MB
CTXSYS 4.625 MB
HR 1.5625 MB
FLOWS_FILES .4375 MB
SYSTEM 22.0625 MB
DBSNMP 1.5625 MB
XDB 69.3125 MB
SYS 360.3125 MB
DATABUS 97.75 MB

OWNER SUM(BYTES)/1024/1024||'MB'
------------------------------ -------------------------------------------
BACKEND .625 MB

12 rows selected.


And if I look in the file system, there's:
[root@testdb1 XE]# du -sh *
6.8M control.dbf
51M log1.dbf
51M log2.dbf
51M log3.dbf
211M sysaux.dbf
321M system.dbf
3.6G temp.dbf
181M undo.dbf
101M users.dbf
[root@testdb1 XE]#

I saw someone mention that temp space isn't counted... but if you add up all the files it's 4.5 gb

The tables (about 200 of them) were created as plain old create table(cols). With a primary key on some, foreign keys on others and no special storage params.

We've recreated the tables a few times (the script to generate the schema drops/creates) and we've run it maybe 10 times.

I now get errors doing any form of insert or table creation:
SQL> create table test ( tester number);
create table test ( tester number)
*
ERROR at line 1:
ORA-12952: The request exceeds the maximum allowed database size of 4 GB


SQL>

So, I'm kind of lost. Maybe someone knows what I'm doing wrong?
fyi: this is a centos 4.1 (rhel 4 equiv) x86_64 box