What are the advantages/disadvantages of using Oracle Auto Segment Space Management?

Question

I've been looking at switching many of our Oracle tablespaces over to use automatic segment space management.

I know that it helps by managing freelists and the like, but I'm curious if anyone has seen any disadvantages to using this option? Major advantages?

Our environment is somewhat a hybrid between an OLTP and Data Warehousing where some tables are large and fairly static, to tables upwards of 700M rows with heavy updates and partitioning.

Answer 1

The essential point of ASSM is that Oracle chooses PCTUSED dynamically and automatically for you and you don't have control over it anymore.

PCTUSED tells how much space should be in a non-free block to become free again (free here means able to accept newly inserted rows)

If you never fine-tuned this parameter for your database, then you will probably benefit from ASSM.