ORA-1652 When Using CTAS With A View?

Environment is Oracle 11gR1 Enterprise Edition (non-RAC) on OEL 5.x.

The user has an assigned temporary tablespace SOME_TEMP which has autoextend on in increments of 1 MB with a maximum size of 5 GB.

User executes:

create table some_table as select * from some_view;

and error ORA-1652 is raised, "Unable to extend temporary tablespace SOME_TEMP".

This is the only user running any queries or statements in the database other than my monitoring session.

I alter the tablespace so it can increase unlimited removing the 5 GB max size. I then run

select count(*) from some_view;

The count is just under 249,000 rows and the query returns in only a few seconds.

I run the user's CTAS statement while periodically checking the size of SOME_TEMP. SOME_TEMP grows fairly quickly past 5 GB to 6, 7, 8, ..., 11 GB and still going after about 3 minutes.

I kill the CTAS statement after SOME_TEMP exceeds 11 GB ... using a view which returns less than 249,000 rows ... and no, the table is not wide enough to use this much temp space for the entire table many times over.

Previous versions of SOME_VIEW have been used to create SOME_TABLE and the CTAS typically completes in under 2 minutes without any errors.A new version of SOME_VIEW was used for the first time to recreate SOME_TABLE when ORA-1652 was raised.

The view returns a fixed number of rows fairly quickly so I think this rules out any logical, recursive errors or unwieldy Cartesian products in the view. what is causing the temporary space to quickly grow so large ?

I expect if I did not terminate the statement, the temporary space would grow until it consumed all available disk space on the system.