摘要：A normalization database is considered as mathematics logical design to avoid redundancies and inconsistencies in the stored data which brought about null data and many relationship tables in the physical database. A retrieval rate is affected directly in running a practical system of the normalization design. We argue in the paper that rate formulas given out retrieval speed via testing the vast amount of data with decomposing fields and data in practical or ideal network environment. The rate formulas show that relationship tables increased must decrease retrieval speed and a minimum table must increase retrieval speed on the contrary, which compared with normal form according to the database theory and practical requirement. A speed is predictable to calculate the rate formulas. The retrieval speed is mainly concerned with server performance base on normal form too.
