-- File DBModelSystemImpl.mesa -- Contents: Initialization of and operations on system tuples -- Last modified by: -- Eric Bier on: 18-Aug-81 14:48:57 -- Rick Cattell on: September 14, 1983 4:19 pm -- Willie-Sue on June 25, 1982 9:26 am DIRECTORY Basics USING [LowHalf], DBStorage, DBTuplesConcrete, DBEnvironment, DB, DBModel, DBModelPrivate, Rope USING [ROPE, Concat]; DBModelSystemImpl: CEDAR PROGRAM IMPORTS DBStorage, DBModel, DBModelPrivate, Basics, Rope EXPORTS DB, DBModelPrivate, DBEnvironment = BEGIN OPEN DBStorage, DB, DBModelPrivate, DBModel; ROPE: TYPE = Rope.ROPE; -- Error and Fatal signals, exported to both DB and DBEnvironment: Error: PUBLIC SIGNAL[code: DBEnvironment.ErrorCode] = CODE; Aborted: PUBLIC ERROR [trans: REF ANY] = CODE; InternalError: PUBLIC SIGNAL = CODE; Failure: PUBLIC ERROR[what: ATOM, info: Rope.ROPE] = CODE; -- Opaque type objects: exported (from DBTuplesConcrete) to DBModel TupleObject: PUBLIC TYPE = DBTuplesConcrete.TupleObject; EntityObject: PUBLIC TYPE = TupleObject; RelshipObject: PUBLIC TYPE = TupleObject; EntitySetObject: PUBLIC TYPE = DBTuplesConcrete.EntitySetObject; RelshipSetObject: PUBLIC TYPE = DBTuplesConcrete.RelshipSetObject; -- REFS to opaque type objects Tuple, TupleSet, Index, IndexFactor: TYPE = REF TupleObject; Domain, Relation, Entity, Attribute, Property, DataType: PUBLIC TYPE = REF EntityObject; Relship: PUBLIC TYPE = REF RelshipObject; EntitySet: PUBLIC TYPE = REF EntitySetObject; RelshipSet: PUBLIC TYPE = REF RelshipSetObject; SystemATuple: TYPE = REF attribute TupleObject; SystemTSTuple: TYPE = REF tupleSet TupleObject; SystemETuple: TYPE = REF entity TupleObject; T2SAT: PROC[t: TupleHandle] RETURNS [SystemATuple] = BEGIN RETURN [NARROW[t]] END; T2STT: PROC[t: TupleHandle] RETURNS [SystemTSTuple] = INLINE BEGIN RETURN [NARROW[t]] END; T2SET: PROC[t: TupleHandle] RETURNS [SystemETuple] = INLINE BEGIN RETURN [NARROW[t]] END; -- Value Types AnyDomainType, BoolType, IntType, RecordType, TimeType, RopeType: PUBLIC DataType; -- The System tuple abstraction systemTupleVec: PUBLIC REF STSVecType _ NEW[STSVecType_ ALL[NIL]]; attributeIDCount: LONG CARDINAL_ 0; -- used in DefineSystemTupleSet and DefineSystemAttribute. -- The system-defined domains, relations, and attributes: grouped by domains -- Items declared to be Properties are attributes with no relation; we don't need the relation -- because it is an internal private binary surrogate relation. The [binary] relations that the -- client may access require both attributes and the relation entity itself, so that the client -- may perform RelationSubset and do a GetP in both directions. DomainDomain: PUBLIC Domain; -- one element per client-defined domain dHandleProp: PUBLIC Property; -- the storage level tupleset handle dIndexProp: PUBLIC Property; -- the storage level index handle for this domain dSubType: PUBLIC Relation; -- one element per direct sub-super type relationship dSubTypeOf: PUBLIC Attribute; -- domain: the super-type dSubTypeIs: PUBLIC Attribute; -- domain: the sub-type RelationDomain: PUBLIC Domain; -- one element per client-defined relation rHandleProp: PUBLIC Property; -- the storage level tupleset handle r1to1Prop: PUBLIC Property; -- TRUE iff this relation is a surrogate relation AttributeDomain: PUBLIC Domain; -- one element per client-defined attribute aHandleProp: PUBLIC Property; -- the storage level handle for this field aTypeCodeProp: PUBLIC Property; -- tid of the type entity, or zero if domain-valued aTypeEntityProp: PUBLIC Property; -- the domain this attribute refs, or NIL if datum-valued aRelation: PUBLIC Relation; -- one element per client-defined attribute aRelationOf: PUBLIC Attribute; -- the attribute aRelationIs: PUBLIC Attribute; -- relation of the attribute aType: PUBLIC Relation; -- one element per client-defined attribute aTypeOf: PUBLIC Attribute; -- the attribute aTypeIs: PUBLIC Attribute; -- domain or datatype of the attribute aUniqueness: PUBLIC Relation; -- one element per client-defined attribute aUniquenessOf: PUBLIC Attribute; -- the attribute aUniquenessIs: PUBLIC Attribute; -- INT corresponding to its uniqueness aLength: PUBLIC Relation; -- one element per client-defined attribute aLengthOf: PUBLIC Attribute; -- the attribute aLengthIs: PUBLIC Attribute; -- INT corresponding to attribute's length aLink: PUBLIC Relation; -- one element per client-defined attribute aLinkOf: PUBLIC Attribute; -- the attribute aLinkIs: PUBLIC Attribute; -- INT corresponding to its LinkType. aDomain: PUBLIC Relation; -- exported to DBModelPrivate: one elt per client-defined attribute aDomainOf: PUBLIC Attribute; -- the attribute aDomainIs: PUBLIC Attribute; -- non-NIL only if this is the first (targetted) attribute of -- a surrogate relation, equals domain where actually -- stored (i.e., equals aTypeEntityProp when non-NIL) aUnlinked: PUBLIC Relation; -- exported to DBModelPrivate: one elt per client-defined attribute aUnlinkedOf: PUBLIC Attribute; -- the attribute aUnlinkedIs: PUBLIC Attribute; -- non-NIL only if this attribute is NOT linked, in which -- case it equals aTypeProp (i.e., the domain referenced) DataTypeDomain: PUBLIC Domain; -- RopeType, BoolType, etc. are of this domain IndexDomain: PUBLIC Domain; -- one element per client-defined index iHandleProp: PUBLIC Property; -- index handle, set by storage level IndexFactorDomain: PUBLIC Domain; -- one element per attribute in an index ifIndex: PUBLIC Relation; -- one element per attribute in an index (an "index factor") ifIndexOf: PUBLIC Attribute; -- the index factor ifIndexIs: PUBLIC Attribute; -- the index this index factor belongs to ifOrdinalPosition: PUBLIC Relation; -- one element per index factor ifOrdinalPositionOf: PUBLIC Attribute; -- the index factor ifOrdinalPositionIs: PUBLIC Attribute; -- the position of this index factor in the ordering ifAttribute: PUBLIC Relation; -- one element per index factor ifAttributeOf: PUBLIC Attribute; -- the index factor ifAttributeIs: PUBLIC Attribute; -- the attribute this index factor indexes -- Other global variables, exported to DBModelPrivate: defaultDomainIndex, defaultRelationIndex: PUBLIC DBStorage.IndexHandle; defaultNameHandle, attributeNameHandle, tupleSetNameHandle: PUBLIC DBStorage.FieldHandle; defaultNameAttribute: PUBLIC Attribute; DefaultNameSize: CARDINAL = 20; -- The following shouldn't go into DB because they might get used before initialized minfString: PUBLIC ROPE _ ""; -- less than any other string infString: PUBLIC ROPE _ "\177"; -- greater than any other string InitializeSystemTuples: PUBLIC PROC = TRUSTED BEGIN dNameProp, rNameProp, aNameProp: Domain; -- only need temporarily DBStorage.SetSystemTupleTable[systemTupleVec]; -- Define the system domains DomainDomain_ DefineSystemDomain[DomainTSID, "Domain"]; RelationDomain_ DefineSystemDomain[RelationTSID, "Relation"]; AttributeDomain_ DefineSystemDomain[AttributeTSID, "Attribute"]; DataTypeDomain_ DefineSystemDomain[DataTypeTSID, "DataType"]; IndexDomain_ DefineSystemDomain[IndexTSID, "Index"]; IndexFactorDomain_ DefineSystemDomain[IndexFactorTSID, "IndexFactor"]; -- Define the DataType entities RopeType_ DefineSystemEntity[RopeTypeID, DataTypeDomain, "RopeType"]; IntType_ DefineSystemEntity[IntTypeID, DataTypeDomain, "IntType"]; TimeType_ DefineSystemEntity[TimeTypeID, DataTypeDomain, "TimeType"]; BoolType_ DefineSystemEntity[BoolTypeID, DataTypeDomain, "BoolType"]; RecordType_ DefineSystemEntity[RecordTypeID, DataTypeDomain, "RecordType"]; AnyDomainType_ DefineSystemEntity[AnyDomainTypeID, DataTypeDomain, "AnyDomainType"]; FakeTheNameHandle[]; -- must call after RopeType defined but before any real entities -- Define (private) properties of domain, relation, attribute, and index entities dHandleProp_ DefinePrivateProperty[ DomainDomain, "dHandleProp", RecordType, DBStorage.TuplesetObjectSize]; -- dHandle must be first field for proper storage level operation! dNameProp_ DefinePrivateProperty[DomainDomain, "dName", RopeType, DefaultNameSize]; tupleSetNameHandle_ T2SAT[dNameProp].vHandle; dIndexProp_ DefinePrivateProperty[DomainDomain, "dIndexProp", IndexDomain]; rHandleProp_ DefinePrivateProperty[ RelationDomain, "rHandleProp", RecordType, DBStorage.TuplesetObjectSize]; -- rHandle must be first field for proper DBStorage operation! rNameProp_ DefinePrivateProperty[ RelationDomain, "rNameProp", RopeType, DefaultNameSize]; -- don't need handle because assume identical pos&size as tupleChangeNameHandle above r1to1Prop_ DefinePrivateProperty[RelationDomain, "r1to1", BoolType]; aHandleProp_ DefinePrivateProperty[ AttributeDomain, "aHandleProp", RecordType, DBStorage.FieldObjectSize]; -- handle need not be first field, but make it that way anyway like other system tuples aNameProp_ DefinePrivateProperty[AttributeDomain, "aName", RopeType]; attributeNameHandle_ T2SAT[aNameProp].vHandle; aTypeCodeProp_ DefinePrivateProperty[ AttributeDomain, "aTypeCodeProp", IntType]; aTypeEntityProp_ DefinePrivateProperty[ AttributeDomain, "aTypeEntityProp", DomainDomain]; iHandleProp_ DefinePrivateProperty[ IndexDomain, "iHandleProp", RecordType, DBStorage.IndexObjectSize]; -- iHandle must be first field of Index entity for proper DBStorage operation! -- Define the system relations and their attributes FakeTheTypeAndLinkRelations[]; [aRelation, aRelationOf, aRelationIs]_ DefineSystemBinary[ id: aRelationTSID, name: "aRelation", of: AttributeDomain, is: RelationDomain]; [aUniqueness, aUniquenessOf, aUniquenessIs]_ DefineSystemBinary[ id: aUniquenessTSID, name: "aUniqueness", of: AttributeDomain, is: IntType]; [aLength, aLengthOf, aLengthIs]_ DefineSystemBinary[ id: aLengthTSID, name: "aLength", of: AttributeDomain, is: IntType]; [aDomain, aDomainOf, aDomainIs]_ DefineSystemBinary[ id: aDomainTSID, name: "aDomain", of: AttributeDomain, is: DomainDomain]; [aUnlinked, aUnlinkedOf, aUnlinkedIs]_ DefineSystemBinary[ id: aUnlinkedTSID, name: "aUnlinked", of: AttributeDomain, is: DomainDomain]; [ifIndex, ifIndexOf, ifIndexIs]_ DefineSystemBinary[ id: ifIndexTSID, name: "ifIndex", of: IndexFactorDomain, is: IndexDomain]; [ifOrdinalPosition, ifOrdinalPositionOf, ifOrdinalPositionIs]_ DefineSystemBinary[ id: ifOrdinalPositionTSID, name: "ifOrdinalPosition", of: IndexFactorDomain, is: IntType]; [ifAttribute, ifAttributeOf, ifAttributeIs]_ DefineSystemBinary[ id: ifAttributeTSID, name: "ifAttribute", of: IndexFactorDomain, is: AttributeDomain]; [dSubType, dSubTypeOf, dSubTypeIs]_ DefineSystemBinary[ id: dSubTypeTSID, name: "dSubType", of: DomainDomain, is: DomainDomain, is1to1: FALSE]; END; FakeTheNameHandle: PROC = -- Sets up fake relation so that defaultNameHandle will work. -- Must be called after RopeType defined. BEGIN fakeReln: TupleSet_ DefineSystemTupleSet[DummyID, "fakeReln", FALSE, FALSE]; defaultNameAttribute_ DefineSystemField[fakeReln, "defaultNameAttribute", RopeType]; defaultNameHandle_ T2SAT[defaultNameAttribute].vHandle; END; FakeTheTypeAndLinkRelations: PROC = -- The aType and aLink relations are tricky, to achieve better performance than the -- obvious implementation. They are actually defined on two underlying properties, -- the aTypeCodeProp and the aTypeEntityProp, which are surrogate attributes of the -- attribute entities. When we do operations on aType or aLink, we must trap them, -- interpreting aTypeCodeProp and aTypeEntityProp as follows: -- (1) If aTypeEntityProp=NIL, then we have a non-entity-valued attribute, and the -- aTypeCodeProp is the tid of the system DataType entity (e.g., RopeType, IntType). -- (2) If aTypeEntityProp#NIL, then it references the domain that is the type of the -- attribute, and aTypeCodeProp= 0 or -1 depending on whether it is linked or not linked. -- Operations fetching or setting aType and aLink are trapped in the low-level procedures -- GetValFromHandle and SetValFromHandle, so that they do not need to be checked -- separately in GetF, SurrogateGetF, GetP, SetF, etc. The low level procedures have -- only the handle for the attribute available, not the attribute itself; they thus must -- do equality comparison to the aTypeIs.vHandle or aLinkIs.vHandle; so the handle is needed -- merely for its unique pointer value, not for the DBStorage.FieldHandleObject it points to. BEGIN aType_ DefineSystemTupleSet[ id: aTypeTSID, name: "aType", isDomain: FALSE, is1to1: TRUE]; aTypeOf_ DefineSystemFieldObject[aType, "aTypeOf", AttributeDomain]; aTypeIs_ DefineSystemField[aType, "aTypeIs", DataTypeDomain]; T2SAT[aTypeIs].vHandle_ T2SAT[aTypeEntityProp].vHandle; -- so group scans work on type T2SAT[aTypeOf].vRelation_ T2SAT[aTypeIs].vRelation_ aType; T2STT[aType].vAttributes_ LIST[aTypeOf, aTypeIs]; aLink_ DefineSystemTupleSet[ id: aLinkTSID, name: "aLink", isDomain: FALSE, is1to1: TRUE]; aLinkOf_ DefineSystemFieldObject[aLink, "aLinkOf", AttributeDomain]; aLinkIs_ DefineSystemField[aLink, "aLinkIs", IntType]; T2STT[aLink].vAttributes_ LIST[aLinkOf, aLinkIs]; T2SAT[aLinkOf].vRelation_ T2SAT[aLinkIs].vRelation_ aLink; END; DefineSystemDomain: PROC [id: LONG CARDINAL, name: ROPE] RETURNS [Domain] = INLINE {RETURN[DefineSystemTupleSet[id, name, TRUE, FALSE]]}; DefineSystemBinary: PROC [ id: LONG CARDINAL, name: ROPE, of: DataType, is: DataType, is1to1: BOOL_ TRUE] RETURNS [r: Relation, rOf, rIs: Attribute] = -- Defines a binary system relation and attributes with types specified by of and is. -- The system relation entity is given the tuple id specified, and attributes are allocated ids. -- The attributes types are "of" and "is" respectively. The relation is given the specified name, -- and the attributes are given the specified name postfixed by the strings "Of" and "Is". -- If is1to1=TRUE, then relation is a "surrogate" relation, and the values are actually stored -- as fields of the domain type of "of". BEGIN r_ DefineSystemTupleSet[id, name, FALSE, is1to1]; IF is1to1 THEN -- The "is" attribute is actually a field of of's domain, not of the relation BEGIN rOf_ DefineSystemFieldObject[of, Rope.Concat[name, "Of"], of]; rIs_ DefineSystemField[of, Rope.Concat[name, "Is"], is, DefaultNameLength]; END ELSE -- Normal attributes: fields of r. BEGIN rOf_ DefineSystemField[r, Rope.Concat[name, "Of"], of]; rIs_ DefineSystemField[r, Rope.Concat[name, "Is"], is, DefaultNameLength]; END; T2STT[r].vAttributes_ LIST[rOf, rIs]; T2SAT[rOf].vRelation_ T2SAT[rIs].vRelation_ r; END; DefineSystemTupleSet: PROC[id: LONG CARDINAL, name: ROPE, isDomain: BOOL, is1to1: BOOL] RETURNS[TupleSet] = TRUSTED -- Defines a system domain or relation, according to the value of isDomain. BEGIN t: SystemTSTuple; IF id>MaxVTID THEN ERROR InternalError; t_ T2STT[DBStorage.ConsSystemTupleObject[tupleSet]]; t.tid_ id; t.vTuple_ DBStorage.CreateSystemTupleset[id]; -- SLevel tuple representing this abstraction t.vName_ name; -- name of this tupleset. t.vR1to1_ is1to1; t.vIsDomain_ isDomain; systemTupleVec[Basics.LowHalf[id]]_ t; RETURN[t] END; DefineSystemField: PROC[ ts: TupleSet, name: ROPE, type: DataType, length: CARDINAL_ 0] RETURNS[Attribute] = TRUSTED -- Used as a subroutine to DefineSystemBinary and DefinePrivateProperty, to define a -- field of domain or relation ts with the given name, type, and length if applicable. BEGIN f: Attribute_ DefineSystemFieldObject[ts, name, type]; -- add a field to ts to hold values of this type: T2SAT[f].vHandle_ DBStorage.AddSystemField[T2STT[ts].vTuple, MakeFD[type, length,, f]]; RETURN[f] END; DefineSystemFieldObject: PROC[ ts: TupleSet, name: ROPE, type: DataType] RETURNS[Attribute] = TRUSTED -- Used as a subroutine to DefineSystemField and DefineSystemBinary. -- Defines the storage level object for a system field, though doesn't actually create the field. BEGIN t: SystemATuple_ T2SAT[DBStorage.ConsSystemTupleObject[attribute]]; t.tid_ FirstAttributeID + attributeIDCount; t.vType_ type; -- what type this attribute can point to t.vName_ name; -- attribute name attributeIDCount_ attributeIDCount+1; IF FirstAttributeID+attributeIDCount>MaxVTID THEN SIGNAL InternalError; systemTupleVec[Basics.LowHalf[attributeIDCount+FirstAttributeID-1]]_ t; RETURN[t] END; DefineSystemEntity: PROC[ id: LONG CARDINAL, d: Domain, name: ROPE] RETURNS [Entity] = TRUSTED -- Use only for DataTypes; creates a system entity object. BEGIN e: SystemETuple_ T2SET[DBStorage.ConsSystemTupleObject[entity]]; e.tid_ id; e.vName_ name; e.vParent_ d; systemTupleVec[Basics.LowHalf[id]]_ e; RETURN[e] END; DefinePrivateProperty: PROC [ d: Domain, name: ROPE, type: DataType, length: INT_ 0] RETURNS [Property] = -- Adds an "invisible" new system relation which is actually a surrogate relation stored -- as a field of the domain d. We use this instead of DefineSystemBinary when the client -- doesn't actually need access to the relation, so we can just define the field alone. -- This proc turns out to be implemented by calling DefineSystemField, but is logically -- quite different since we are defining an "attribute" of a domain, not a relation. We fake -- the call by pretending the domain is a relation (they are both TupleSets, the same type). -- We add the fake attribute to the vAttributes list on the domain, so it can be used to -- optimize SafeGetP and other operations. BEGIN fakeAttribute: Attribute; fakeAttribute_ DefineSystemField[d, name, type, length]; T2STT[d].vAttributes_ CONS[fakeAttribute, T2STT[d].vAttributes]; T2SAT[fakeAttribute].vRelation_ d; RETURN[fakeAttribute] END; -- Operations on system tuples SystemDomainSubset: PUBLIC PROC[ d: Domain, lowName, highName: ROPE, segment: Segment] RETURNS [es: EntitySet] = TRUSTED -- Domain d must be DomainDomain or RelationDomain. We implement an index scan on the -- domain or relation index in the given segment, with names in the given range. -- Note that there is no tuple set scan possible through domains or relations, because -- the storage level provides no links through the system tuples. -- Scans on the AttributeDomain, IndexDomain, and IndexFactorDomain are not currently -- implemented. They must be accessed via system relations instead. -- If segment=NIL, all segments are searched, by creating a recursive "segment" EntitySet. -- Otherwise just the given segment is searched. BEGIN MakeIndexScan: PROC[indexToScan: DBStorage.IndexHandle] RETURNS[EntitySet] = TRUSTED BEGIN tsScan: DBStorage.IndexScanHandle; [lowName, highName]_ NCodeAndDefaultLimits[lowName, highName]; tsScan_ DBStorage.OpenScanIndex[indexToScan, [lowName, highName, TRUE, TRUE], First ]; RETURN[NEW[EntitySetObject[index] _ [index[tsScan]]]]; END; IF segment=NIL THEN es_ NEW[EntitySetObject[segment] _ [segment[ remainingSegments: DBModel.QGetSegments[], domain: d, lowName: lowName, highName: highName, start: First, currentEntitySet: NIL]]] ELSE SELECT d FROM DomainDomain => es_ MakeIndexScan[GetDomainIndex[segment]]; RelationDomain => es_ MakeIndexScan[GetRelationIndex[segment]]; ENDCASE => {SIGNAL Error[NotImplemented]; RETURN[NIL]}; END; SystemGetP: PUBLIC PROC [e: Entity, aIs: Attribute] RETURNS [v: Value] = TRUSTED -- Fetches properties of system entities. Need only work with single-valued properties. -- System entities are not defined to have the following properties: -- dHandleProp, dIndexProp dSubTypeOf, dSubTypeIs, rHandleProp -- aTypeCodeProp, aTypeEntityProp, aRelationIs. BEGIN WITH e^ SELECT FROM e1: TupleObject[tupleSet] => -- e is one of the five system domains SELECT aIs FROM r1to1Prop => v_ NEW[BOOL_ e1.vR1to1]; ENDCASE => SIGNAL Error[NotImplemented]; e1: TupleObject[attribute] => -- e is one of the system attributes SELECT aIs FROM aHandleProp => v_ e1.vHandle; aTypeIs => v_ e1.vType; aRelationIs => v_ e1.vRelation; aLinkIs => v_ NEW[BOOL_ TRUE]; ENDCASE => SIGNAL Error[NotImplemented]; ENDCASE => SIGNAL Error[NotImplemented]; -- No other kinds implemented RETURN[v] END; SystemGetName: PUBLIC PROC [e: Entity] RETURNS [ROPE] = BEGIN WITH e^ SELECT FROM e1: TupleObject[tupleSet] => RETURN[e1.vName]; e1: TupleObject[attribute] => RETURN[e1.vName]; e1: TupleObject[entity] => RETURN[e1.vName]; ENDCASE => SIGNAL Error[NotImplemented]; RETURN[NIL] END; NCodeAndDefaultLimits: PROC [low, high: ROPE] RETURNS [newLow, newHigh: ROPE] = TRUSTED -- Used by DomainSubset and RelationSubset to default limits on an index search. The -- rules are: (1) if both high and low limits are NIL, the whole index is searched. -- (2) if just the high limit is NIL, it defaults to the low limit, (3) any any case, we -- must call NCode to convert to all upper case. BEGIN IF high=NIL THEN IF low=NIL THEN {low_ minfString; high_ infString} ELSE {low_ NCode[low]; high_ low} ELSE {low_ NCode[low]; high_ NCode[high]}; RETURN[low, high] END; END. Last edited by: Cattell on 19-Dec-81 9:31:31: Changed iTupleSetProp and ifXXXProps to have underlying attributes. Bug had arisen when attempted to do GroupScan on iTupleSetProp, because there was no underlying attribute and therefore no unique fieldID to do the groupscan upon (a random memory location had been used). Decided to disallow entity-reffing fields without explicit underlying attributes so this won't happen (so DefineSystemProperty only works with simple-valued attributes). Cattell on 19-Dec-81 9:31:31: Changed aType* stuff around; may have to do more on this. Cattell on 29-Dec-81 16:09:49: Almost completely rewrote SystemDomainSubset: handle more special cases and do so correctly. Cattell on April 28, 1982 9:42 am: Added call to NCode in SystemDomainSubset and DesiredPropValue, so upper-case-only works. Cattell on August 2, 1982 11:16 pm: SubType relation attributes should be DomainDomain type, not AnyDomainType. Cattell on November 4, 1982 11:24 am: Conversion to new property scheme. This involves complete rework of system relations and domains, and the procedures used to initialize them. SystemRelationSubset and SystemGetP also rewritten. Cattell on December 17, 1982 5:18 pm: Converstion to new segment scheme, new Error scheme.