Schema.Equal does not compare schema metadata, but does compare field metadata

[lidavidm]

Describe the enhancement requested

Equal does not compare the metadata.

arrow-go/arrow/schema.go

Lines 225 to 245 in 2900ed6

	// Equal returns whether two schema are equal.
	// Equal does not compare the metadata.
	func (sc *Schema) Equal(o *Schema) bool {
	switch {
	case sc == o:
	return true
	case sc == nil || o == nil:
	return false
	case len(sc.fields) != len(o.fields):
	return false
	case sc.endianness != o.endianness:
	return false
	}
	for i := range sc.fields {
	if !sc.fields[i].Equal(o.fields[i]) {
	return false
	}
	}
	return true
	}

But Field.Equal does compare the metadata:

arrow-go/arrow/datatype_nested.go

Lines 956 to 968 in 2900ed6

	func (f Field) Equal(o Field) bool {
	switch {
	case f.Name != o.Name:
	return false
	case f.Nullable != o.Nullable:
	return false
	case !TypeEqual(f.Type, o.Type, CheckMetadata()):
	return false
	case !f.Metadata.Equal(o.Metadata):
	return false
	}
	return true
	}

This is a little inconsistent. Ideally we would be able to choose how to compare. We could do the comparison ourselves but it's rather tedious, as we have to recurse into every type to find child fields. (Incidentally, if the DataType interface had a method to get the child fields (possibly empty) regardless of type, this would become much easier.)

Component(s)

Other

[zeroshade]

as we have to recurse into every type to find child fields. (Incidentally, if the DataType interface had a method to get the child fields (possibly empty) regardless of type, this would become much easier.)

You can do:

if n, ok := dt.(arrow.NestedType); ok {
        for _, f := range n.Fields() {

        }
}