Indexing
- primary mechanism to improve performance of database
- persist data structures stored in database (hash tables/B trees/B+ trees)
- trade off:
scale of databaseandworkload(query/update rate)as input of physical design advisors
CREATE INDEX IndexName on T(A)
CREATE INDEX IndexName on T(A1, A2, ..., An)
CREATE UNIQUE INDEX IndexName on T(A)
DROP INDEX IndexName