[postgis-devel] Coordinate compression for native PostGIS geometry storage?

[Martin Davis]

Has anyone thought about or tested the idea of compressing the 
coordinate sequences in PostGIS' internal geometry data structure? 

Typical sequences of ordinates for real-world geometries tend to have a 
significant number of identical bits at the high end of each number 
(sometimes as much as 40%).  With a suitable encoding method a lot of 
this redundancy could be squeezed out. 

This is obviously a time/space trade-off - but CPU is so much faster 
than disk I/O it seems like it could be a win to compress.

Perhaps something to discuss with the big brains at the code sprint...

-- 
Martin Davis
Senior Technical Architect
Refractions Research, Inc.
(250) 383-3022