logical and operator

基本解释

Consider using parentheses to improve readability and avoid mistakes because of logical operator precedence.
考虑使用括号来改善可读性和避免由于逻辑操作符的优先级导致的错误。
A logical operator that consists of a logical AND followed by a logical NOT and returns a false value only if both operands are true.
由逻辑与和其后的逻辑非组成的逻辑运算符，如果两个运算域都是真，则返回的值便为假。
It's best to read such execution plans from the left-lowest operator in the tree, since the logical flow in the plan is from bottom to top and left to right.
因为执行计划中的逻辑流是自下而上、从左到右，所以看此类执行计划时，最好是从树中左下方的操作符开始。