shrink a segment

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Oracle 10g Segment shrink
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Mandatory
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Init.ora parameter 'Compatible' must be >=10.0

Shrink operations can be performed only on segments in locally managed
tablespaces with automatic segment space management (ASSM).


How it works
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1. Enable row movement for the table.
SQL>  ALTER TABLE scott.emp ENABLE ROW MOVEMENT;

2. Shrink table but don't want to shrink HWM (High Water Mark).
SQL>  ALTER TABLE scott.emp SHRINK SPACE COMPACT;

3. Shrink table and HWM too.
SQL>  ALTER TABLE scott.emp SHRINK SPACE;

4. Shrink table and all dependent index too.
SQL>  ALTER TABLE scott.emp SHRINK SPACE CASCADE;

5. Shrink table under MView.
SQL>  ALTER TABLE