Can a large number of extents result in performance problems?
Using an extent size that is too low, and the resulting necessity for a number of extents that are too high, may cause serious performance problems in DMTS due to space transaction enqueues (ST enqueues) if extents are allocated or released (for example, within INSERTs or TRUNCATEs). For more information, refer to the “enqueue” section in Note 619188. In LMTS, the presence of a large number of extents is clearly less critical. However, here you should also avoid increasing the number of extents of a segment into five-digit areas.