[Oracle] Batch inserts/updates with LOBs don't free temporary LOB

[leitaop]

On batch updates with LOB columns with a size greater than 4000 bytes, the oracle driver uses a temporary LOB that is never freed because PDB uses a single PreparedStatement for the whole session.

This can be reproduced by doing multiple inserts with the batch update interface and checking that the temporary LOB space used by the connection keeps growing -- use select CACHE_LOBS
from V$TEMPORARY_LOBS to verify this.