MDX Vs T-SQL
i)
The ability of MDX to reference multiple dimensions but SQL
refers to only two dimensions, columns and rows when processing queries.
ii)
In SQL, the SELECT clause is used to define the column layout for
a query, while the WHERE clause is used to define the row layout. However, in
MDX the SELECT clause can be used to define several axis dimensions, while the
WHERE clause is used to restrict multidimensional data to a specific dimension
or member.
iii)
The process of creating an SQL query is also different than that
of creating an MDX query.
iv)
The visualization of an SQL result set is intuitive; the set is a
two-dimensional grid of columns and rows. The visualization of an MDX result
set is not as intuitive, however. Because a multidimensional result set can
have more than three dimensions.
v)
To refer to such two-dimensional data in SQL, the name of a column
and the unique identification of a row, in whatever method is appropriate for
the data, are used to refer to a single cell of data, called a field. However,
MDX uses a very specific and uniform syntax to refer to cells of data, whether
the data forms a single cell or a group of cells.
