Dictionary-managed tablespaces (DMTs) use the data dictionary for extent management, whilelocally managed tablespaces (LMTs) use bitmaps. Let’s evaluate compatibility:
A. Capacity planning growth reports based on historical data in the Automatic Workload Repository (AWR).
Explanation:True. AWR tracks space usage (e.g., DBA_HIST_TBSPC_SPACE_USAGE) regardless of tablespace type, enabling growth reports for both DMTs and LMTs.
Mechanics:MMON collects metrics like segment growth, stored in SYSAUX, accessible via EM or scripts.
Practical Use:Helps predict when to add data files, universal across management types.
B. Online table segment shrink.
Explanation:False. ALTER TABLE ... SHRINK SPACE requires LMTs with Automatic Segment Space Management (ASSM), unavailable in DMTs, which lack bitmap-based free space tracking.
Why Incorrect:DMTs use freelists, incompatible with shrink operations.
C. Online index segment shrink.
Explanation:False. Like tables, ALTER INDEX ... SHRINK SPACE requires LMTs with ASSM, not supported in DMTs.
Why Incorrect:Same limitation as B; DMTs can’t compact online.
D. Oracle Managed Files (OMF).
Explanation:True. OMF automates file naming and placement (via DB_CREATE_FILE_DEST) for both DMTs and LMTs, agnostic to extent management.
Mechanics:Example: CREATE TABLESPACE ts1; creates an OMF file in either type.
Edge Case:DMTs are rare in 23ai, but OMF still applies.
E. Automatic data file extension (AUTOEXTEND).
Explanation:True. AUTOEXTEND ON allows data files to grow as needed, supported in both DMTs and LMTs since early versions.
Mechanics:ALTER DATABASE DATAFILE ... AUTOEXTEND ON NEXT 100M; works universally.
