Describes data stores, i.e., entities storing data, such as a relational
database, an object-oriented database, an LDAP directory, a UDDI directory,
an XML document store, a text file storage system, etc.
For a given Expression used at a QueryNode, sets the index of its
FieldOperands (index in the tuple resulting from the concatenation
of the children QueryNode tuples).
Returns the name of the column, either in the SQL ResultSet in the case
of RdbStringQueryLeaf, or the name of the column in the QualifiedTable
in the case of RdbExpQueryLeaf.
It adds the default Medor rules in this following order
PushNotInExpressionRule
PushSelectionRule
DropUnusedProjFieldsRule
DropUselessNodeRule
GroupSameStoreRule
An integer with position i in this array gives the position of the
corresponding field (field number i of the TupleStructure of this
QueryNode) in the array made of the concatenation of the array of fields
from all children of this QueryNode.
The InCollection class is an operator testing whether the value of a
Field (the left operand, which is supposed to be a FieldOperand) is equal to
one of the elements of a collecton (the right Operand)
The MemberOf class is an operator testing whether the value of a list of
Fields (the first n operands, which are supposed to be FieldOperands or
ParameterOperands) are
equal to one of the values of another list of Fields (the second n operands,
which are supposed to be FieldOperands).
Represents an element of an "order by" clause, qualified by a field and
a boolean indicating whether the order is descendant (false, default)
or ascendant.
This interface represents objects that manipulate query trees, such as
a logical query rewriter, a query optimizer for choosing the right
join algorithm, etc, and an executable query plan generator.
An RdbExpQueryLeaf is a particular type of RdbQueryLeaf for which the
associated SQL query if not given as a SQL String, but is computed from
an Expression (representing the filter) and from abstract information
made of QualifiedTables, representing the FROM part of the SQL query.