Examine the details of the uncompressed, non-partitioned heap table CITIES. Examine the command: SQL> ALTER TABLE cities SHRINK SPACE COMPACT; What must you do before executing it?

While shrinking space reclaims free space, there is no prerequisite to ensure a specific amount of free space exists or is available before executing the command; the database identifies and reclaims it.

The shrink operation can be performed even with pending transactions, though it might wait for necessary locks to be released; it does not require that there are no pending transactions as a precondition.

The `ALTER TABLE ... SHRINK SPACE` command physically reorganizes table data within blocks to reclaim unused space. This operation involves moving individual rows, which necessitates that row movement be enabled for the table using `ALTER TABLE table_name ENABLE ROW MOVEMENT` before the shrink operation can proceed.

Disabling indexes is not required before shrinking a table; Oracle automatically manages and updates indexes during the shrink operation to maintain data integrity.