Note on duplication:
This is not a duplicate of "Oracle extents - How can I have so many with this small size?" This is a separate question I entered which happens to be in the same domain.
This is a duplicate of "Oracle extents - how is it possible to get so many? [closed]" - this is a question that was closed because someone thought it was a duplicate of the above question, apparently without reading either question, and despite the fact that neither question had an answer. I see why this Stackexchange is not exactly flourishing.
This is more curiosity about how Oracle Database works than anything I need to change (yes I know multiple extents are fine, I read Tom Kyte too).
I have an index with the following characteristics:
Size: 376MB Initial Ext: 118MB Next Ext: 1MB Num Extents: 12
In case it's not apparent, my question is, how can I have something that size, with those extents sizes, and only 12 extents? 376 > 118 + (1 * 11)
FYI: to Justin Cave, yes, it's locally-managed.