Data File Size

Question

I wrote a java program that copies data from a Sql Server DB to Oracle 9i.
As the program ran, the oracle9i server ran out of disk space. I ran the 'clean' portion of my application that deletes all data from the tables. After I did this, there was still the same amout of free space on the hard drive.
I am not an oracle dba or expert by any means, I am a programmer but here is what I found, I'm not sure if its revelent.
On the oracle server I went to the following folder : oracle\ora92\database\DB40
I think this is the file where my data is stored. The file 'DB40DF' is 6 Gigs.
I have 2 other databases on the server that are exactly the same as my db40 database and their 'DF' file sizes are 130MB. These have no data in them yet. So from this I would assume that if I emptied all of my tables then the DB40DF should be around 130MB. But this is not the case, after I ran my delete code the file is still 6GIG.
Did I do my delete wrong? I assumed that my statment would commit and it seems to. When I do a select * from the tables there is no data. If there is no data in my table why is the file 6 gigs? I have included my delete java code incase I did something wrong on that side. If not, is there something I am suspose to do to get the DF file back to normal size? I have Toad 9.5 to administer the database.
Here is a portion of my delete java code:
stmt is a java.sql.Statement
for (String table : tables) {
sql = "DELETE FROM " + oracleSchema + table;
stmt.addBatch(sql);
int[] result = stmt.executeBatch();
if (stmt != null) {
stmt.close();
stmt = null;
When I print out the int array it shows how many rows were deleted from each table and the record cound seems ok. (ie table x clear 36007 rows deleted)
Thank you.

Answer 1

Oracle won't resize a datafile unless this is requested by the SQL statement ALTER DATABASE DATAFILE ... RESIZE... . Oracle won't release extents allocated to a table unless this is requested by the some ALTER TABLE statements. Extents will normally be reused by next INSERT statements. So the behavior you note is normal.