Index[SYMBOL] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [Q] [R] [S] [T] [U] [V] [W] [X] scalar second normal form 2nd SELECT - FROM - WHERE too rigid SELECT DISTINCT (SQL) selector 2nd relation scalar tuple self-referencing relvar semantic optimization semidifference SEMIJOIN semijoin SEMIMINUS semistructured model set membership set-level operations Shakespeare, William Simon, Alan R. single-relvar constraint sixth normal form 2nd snapshot SQL expression evaluation not same as relational model pronouncing SQL SQL:1999 SQL:2003 standard SQL statement versus expression 2nd Stoll, Robert R. Stonebraker, Mike strong typing subset 2nd summarize SUMMARIZE BY SUMMARIZE PER superkey 2nd superset 2nd surrogate system-defined type 2nd |