If the tablespace storage option was not specified during the creation of the ST_Geometry attribute, the LOB segment is automatically created in the user's default tablespace. This may not be the optimial location, making it necessary to move the LOB segment to a new tablespace.
Instructions provided describe how to move the ST_Geometry points' LOB segment to a new tablespace.
SQL> ALTER TABLE streets
2 MOVE LOB(shape.points) STORE AS(TABLESPACE lob_seg_tbs);
After moving an object it is recommended to gather new table statistics. See Oracle's documentation for additional information.