[EMAIL PROTECTED] wrote:
I have a fairly simple database design with a series of tables that reference
graphical data. Currently, there is one table that contains the following:
CREATE TABLE polygons (id INTEGER PRIMARY KEY, externalref INTEGER, pointcount
INTEGER, pointlist BLOB)
When I insert data to this table, I have to write a binary list of x,y
coordinates in a sequential memory region before storing in the database.
Getting information back from the database requires a conversion in the
opposite direction. Typically these lists contain 10-20 points, so they are
not very large.
This currently works, but I'm wondering if it would be better to create a new
table for the points and reference the polygon primary key:
CREATE TABLE pointlist (polyid INTEGER, x INTEGER, y INTEGER)
On average, I'm managing 50000+ polygons, so the pointlist could exceed 1
million entries very easily. Points are not shared between polygons.
Does anyone have a recommendation as to which solution would be more optimal,
both for space and processing time? In a worst case scenario, I could insert
over 1 million polygons, resulting in a max 20 million point list table.
Thanks,
John
you will need some form of spatial indexing if you want to retrieve your
data faster. I use a simpe quad-tree but I'm sure that better design exist.
--
Noël Frankinet
Gistek Software SA
http://www.gistek.net
