Originally posted by saneja
How hard is it to change a production dictionary managed tablespace into a locally managed tablespace ..Can this be done without exp/imp?
Not hard at all. Create a new database with the tablespaces as LMT's, then do the import of the data.


Are there any performance benefits over DMT..
Enough that DMT's will be going by the wayside. In future releases of Oracle, all tablespaces will be LMT's.


What are the convincing reasons to put LMT instead of DMT for existing production tablespaces.
See Note 105120.1 on MetaLink
A Locally Managed Tablespace is a tablespace that manages its own extents maintaining a bitmap in each datafile to keep track of the free or used status of blocks in that datafile. Each bit in the bitmap corresponds to a block or a group of blocks. When the extents are allocated or freed for reuse, Oracle changes the bitmap values to show the new status of the blocks. These changes do not generate rollback information because they do not update tables in the data dictionary (except for tablespace quota information), unlike the default method of Dictionary - Managed Tablespaces. ** Reduced recursive space management ** Reduced contention on data dictionary tables ** No rollback generated ** No coalescing required


Is it really worth it?
Enough that Oracle Corp. is making all TS's LMT's in the future.