I've noticed that some organizations forget to enable SPATIAL_VECTOR_ACCELERATION in Oracle databases...now that Oracle Spatial is free.
Oracle Spatial Vector Acceleration: Flick the Switch
So for any of us who use SDO_GEOMETRY, we need to remember to enable that parameter — to make use of it's performance boosting functionality. (It's enabled by default in 21c+.)
I just thought I'd mention that...for those of us who were unaware.
Note:
I've asked the Oracle Spatial team if there's a way to check if SPATIAL_VECTOR_ACCELERATION is enabled (as a non-dba). But I haven't found a solution yet.