SMON
coalesces free space (extents) into larger, contiguous extents every 2 hours
and even then, only for a short period of time.
SMON
will not coalesce free space if a table space’s default storage parameter
"pctincrease" is set to 0. With Oracle 7.3 one can manually coalesce
a table space using
ALTER
TABLESPACE ... COALESCE;
Command,
until then use
SQL>
alter session set events 'immediate trace name coalesce level n';
Where 'n' is the tablespace number you get from
SELECT TS#, NAME FROM SYS.TS$;