A leading portion of an index is a set of one or more columns that were specified first and consecutively in the list of columns in the
CREATE INDEX statement that created the index. Consider this
CREATE INDEX statement:CREATE INDEX comp_ind
ON table1(x, y, z);
- x, xy, and xyz combinations of columns are leading portions of the index
- yz, y, and z combinations of columns are not leading portions of the index
阅读(1955) | 评论(0) | 转发(0) |
