what is the difference between row migration & row changing?
Migration: The data is stored in blocks whic use Pctfree 40% and pctused 60% ( normally). The 40% space is used for update and delete statements . when a condition may arise that update/delete statement takes more then pctfree then it takes the space from anther block. this is called migration.
RowChaining: while inserting the data if data of one row takes more then one block then this row is stored in two blocks and rows are chained.
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