[postgis-devel] dbf attributes size

[strk at refractions.net]

Hello there, I'm taking a look at shp2pgsql and pgsql2shp
trying to make numerical attribute size handling stricter.

Currently, the loader uses this conservative/pessimistic mapping:

	DBF_SIZE	SQL_TYPE
	0-9		int4		
	10-18		int8		
	19-x		numeric(size,0)

And the dumper uses a size of 16 of dbf attributes of any sql integer type:

	SQL_TYPE	DBF_SIZE
	int2		16
	int4		16
	int8		16

For what I can tell the correct mapping between integer DBF attributes
and sql types should be as follows:

	DBF_SIZE	SQL_TYPE	LONGEST_TEXT_REP
	0-6		int2		-32768
	7-11		int4		-2147483648
	12-20		int8		-9223372036854775808
	21-x		numeric(size,0)

Does anyone see any drawback in implementing this mapping ?


--strk;