Catalog Information
Relevant catalog information about relations includes:
- nr , number of tuples in the relation
- br , number of blocks containing relation r
- sr , size of a tuple of relation r in bytes
- fr , blocking factor, number of tuples/block
- V(A,r), number of distinct values that appear in the relation r for attribute A.
- SC(A,r), selection cardinality of attribute A of relation r. Average number of records that satisfy equality condition for attribute A. 1 if A is key attribute, A(A,r) / nr for one distributed evenly.
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