In this section we show how to define schema in BNF notation.
Bold type words are those which must be written as they are, and slanted
type words are data types. Please see Kappa user's manual for the
details related to distributed databases and so on which are
omitted here.
<Schema>::=TableName(TableProperty,AttrList,NestSequence,
HorizontalDecompositionInfo)
TableName::= ATOM 
nil
TableProperty::= primitive
AttrList::={Attr 
AttrList}
NestSequence::=[AttrName 
NestSequence] 
[]
AttrName::= ATOM
HorizontalDecompositionInfo::= shd(HorizontalDecompositionMethod,
HorizontalDecompositionInfoList) 
nil
Attr::=AttrName(RepetitiveProperty,AttrPropertyList) 
AttrName(RepetitiveProperty,AttrList)
RepetitiveProperty::= set 
single
AttrPropertyList::=[AttrProperty 
AttrPropertyList] 
[]
AttrProperty::= type(DataType) 
key(KeySpecification) 
key(primary,ReferenceKeyInfo) 
access(AccessSpecification) 
null_value(NullValueSpecificaion) 
overflow(OverflowSpecification)
DataType::= string 
integer 
term
KeySpecification::= table 
set 
non_key
NullValueSpecification::= not_allowed 
allowed 
not_nil 
not_bottom
OverflowSpecification::= not_allowed