No support for bigint in shp2pgsql.

[EvanCarroll]

I believe there is a bug where bigint is not supported in shp2pgsql, please check my notes, verification needed.

​https://gis.stackexchange.com/a/254399/6052

[pramsey]

Interested to know if r15639 makes a meaningful difference. The actual stack question seemed to not make sense: the behaviour in an over-wide integer field in shp2pgsql is to use numeric as the type, not double, so the fact that the use was seeing double types is not consistent with what the code says. If their data was in a field with a non-zero precision value, it might end up treated as float no matter what.

The important thing to note is that ogr and shp2pgsql both guess the type mappings based on the dbf header, not the data in the file, so if your header says a field is a number(12,5), you're getting a float field there, even if the data itself is just small integers.