CREATE unique INDEX i_myindex ON myschema.table1 ( column1, column1, column1 ) tablespace INDEX_TBS;

select b.file_name, bytes_full, bytes_total, trunc(bytes_full/bytes_total, 4)*100 as pct_used from v$database a, dba_data_files b,
(select tablespace_name, sum(bytes) bytes_full from dba_extents group by tablespace_name) c,
(select tablespace_name, sum(bytes) bytes_total from dba_data_files group by tablespace_name) d
where b.tablespace_name = c.tablespace_name
and b.tablespace_name = d.tablespace_name

ORA-01536: space quota exceeded for tablespace '%s'
 *Cause:  The space quota for the segment owner in the tablespace has
          been exhausted and the operation attempted the creation of a
          new segment extent in the tablespace.
 *Action: Either drop unnecessary objects in the tablespace to reclaim
          space or have a privileged user increase the quota on this
          tablespace for the segment owner.

alter user myuser quota 20M on INDEX_TBS;