You could also create an index as "create index idx_object_id on objects(object_id,0)" to include nulls in the index.

Good list -- could combine 1 & 2, or could consider creating the indexes prior to the insert if they are few in number and the total size of indexed column data is small relative to total size of table data.

0. Shutdown the standard edition instance cleanly?

I'd try the forums at Oracle Technet -- much more experience of this sort of thing there.

@haki Do you want your i/o from files outside the database of from tables inside? If you get the loading design right with external tables, you read them once and perform all of your loading in as few queries as possible -- with SQL*Loader you have to use an external scheduling tool, load into a table with minimum flexibility on data transformations, and then query the data again after it's loaded. External tables are superior in almost every respect.

@ThinkJet Maybe it was true a long time ago -- I don't think it has been for quite some time if it ever was. Null numbers take up one byte of space in a row, which is just the marker for the new column, so there's no room in there for the representation of NULL as a number of any form.

@ThinkJet do you have a source for the information on Oracle storing numeric nulls as -0? I have doubts about it.

Unlikely that an index is going to help, due to low selectivity.