I have two identical Oracle tables. Table A was created as a "create table as...where 1=0" from Table B. Table B was truncated prior to inserting the data into it.
Each have the same fields, indexes and belong to the same tablespace. Table B has about half of the empty blocks as Table A.
When a user runs process XYZ to load data into either table, the insert takes way longer for Table B than it does for Table A.