Module 5: Disk-based Index Structures
Lecture 26: Pyramid Technique and VA-files
Locational code
Numbering of pyramids
Pyramid
has base
0
for dimension
j
Pyramid
has base
1
for dimension
j
Determination of pyramid for a point
Find dimension
j
where
is maximized
If
,
i.e.
,
where
If
,
, i.e.,
where
Height of a point
in a pyramid
where
Locational code for point
Many-to-one mapping
has base 0 for dimension j
has base 1 for dimension j
is maximized
, 
i.e.,
where 
, 
, i.e., 
in a pyramid
where 
