*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/catalog/pg_operator.c,v 1.33 1999/02/13 23:14:57 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/catalog/pg_operator.c,v 1.34 1999/04/11 02:30:59 tgl Exp $
*
* NOTES
* these routines moved here from commands/define.c and somewhat cleaned up.
#endif
static Oid OperatorGetWithOpenRelation(Relation pg_operator_desc,
- const char *operatorName,
- Oid leftObjectId,
- Oid rightObjectId);
+ const char *operatorName,
+ Oid leftObjectId,
+ Oid rightObjectId,
+ bool *defined);
+
static Oid OperatorGet(char *operatorName,
- char *leftTypeName,
- char *rightTypeName);
+ char *leftTypeName,
+ char *rightTypeName,
+ bool *defined);
static Oid OperatorShellMakeWithOpenRelation(Relation pg_operator_desc,
char *operatorName,
Oid leftObjectId,
Oid rightObjectId);
+
static Oid OperatorShellMake(char *operatorName,
char *leftTypeName,
char *rightTypeName);
static void OperatorDef(char *operatorName,
- int definedOK,
char *leftTypeName,
char *rightTypeName,
char *procedureName,
bool canHash,
char *leftSortName,
char *rightSortName);
+
static void OperatorUpd(Oid baseId, Oid commId, Oid negId);
/* ----------------------------------------------------------------
* ----------------------------------------------------------------
* pg_operator_desc -- reldesc for pg_operator
* operatorName -- name of operator to fetch
- * leftObjectId -- left oid of operator to fetch
- * rightObjectId -- right oid of operator to fetch
+ * leftObjectId -- left data type oid of operator to fetch
+ * rightObjectId -- right data type oid of operator to fetch
+ * defined -- set TRUE if defined (not a shell)
*/
static Oid
OperatorGetWithOpenRelation(Relation pg_operator_desc,
const char *operatorName,
Oid leftObjectId,
- Oid rightObjectId)
+ Oid rightObjectId,
+ bool *defined)
{
HeapScanDesc pg_operator_scan;
Oid operatorObjectId;
* ----------------
*/
tup = heap_getnext(pg_operator_scan, 0);
- operatorObjectId = HeapTupleIsValid(tup) ? tup->t_data->t_oid : InvalidOid;
+
+ if (HeapTupleIsValid(tup))
+ {
+ regproc oprcode = ((Form_pg_operator) GETSTRUCT(tup))->oprcode;
+ operatorObjectId = tup->t_data->t_oid;
+ *defined = RegProcedureIsValid(oprcode);
+ }
+ else
+ {
+ operatorObjectId = InvalidOid;
+ *defined = false;
+ }
/* ----------------
* close the scan and return the oid.
static Oid
OperatorGet(char *operatorName,
char *leftTypeName,
- char *rightTypeName)
+ char *rightTypeName,
+ bool *defined)
{
Relation pg_operator_desc;
bool rightDefined = false;
/* ----------------
- * look up the operator types.
+ * look up the operator data types.
*
* Note: types must be defined before operators
* ----------------
leftObjectId = TypeGet(leftTypeName, &leftDefined);
if (!OidIsValid(leftObjectId) || !leftDefined)
- elog(ERROR, "OperatorGet: left type '%s' nonexistent", leftTypeName);
+ elog(ERROR, "OperatorGet: left type '%s' nonexistent",
+ leftTypeName);
}
if (rightTypeName)
if (!((OidIsValid(leftObjectId) && leftDefined) ||
(OidIsValid(rightObjectId) && rightDefined)))
- elog(ERROR, "OperatorGet: no argument types??");
+ elog(ERROR, "OperatorGet: must have at least one argument type");
/* ----------------
* open the pg_operator relation
operatorObjectId = OperatorGetWithOpenRelation(pg_operator_desc,
operatorName,
leftObjectId,
- rightObjectId);
+ rightObjectId,
+ defined);
/* ----------------
* close the relation and return the operator oid.
}
/* ----------------
- * initialize *values with the type name and
+ * initialize *values with the operator name and input data types.
+ * Note that oprcode is set to InvalidOid, indicating it's a shell.
* ----------------
*/
i = 0;
values[i++] = NameGetDatum(&oname);
values[i++] = Int32GetDatum(GetUserId());
values[i++] = (Datum) (uint16) 0;
-
- values[i++] = (Datum) 'b'; /* fill oprkind with a bogus value */
-
+ values[i++] = (Datum) 'b'; /* assume it's binary */
values[i++] = (Datum) (bool) 0;
values[i++] = (Datum) (bool) 0;
values[i++] = ObjectIdGetDatum(leftObjectId); /* <-- left oid */
* Algorithm:
*
* check if operator already defined
- * if so issue error if not definedOk, this is a duplicate
- * but if definedOk, save the Oid -- filling in a shell
+ * if so, but oprcode is null, save the Oid -- we are filling in a shell
+ * otherwise error
* get the attribute types from relation descriptor for pg_operator
* assign values to the fields of the operator:
* operatorName
* the same as the main operatorName, then create
* a shell and enter the new ObjectId
* else if this does not exist but IS the same
- * name as the main operator, set the ObjectId=0.
- * Later OperatorCreate will make another call
- * to OperatorDef which will cause this field
- * to be filled in (because even though the names
- * will be switched, they are the same name and
- * at this point this ObjectId will then be defined)
+ * name & types as the main operator, set the ObjectId=0.
+ * (We are creating a self-commutating operator.)
+ * The link will be fixed later by OperatorUpd.
* negatorObjectId -- same as for commutatorObjectId
* leftSortObjectId -- same as for commutatorObjectId
* rightSortObjectId -- same as for commutatorObjectId
* --------------------------------
* "X" indicates an optional argument (i.e. one that can be NULL)
* operatorName; -- operator name
- * definedOK; -- operator can already have an oid?
* leftTypeName; -- X left type name
* rightTypeName; -- X right type name
- * procedureName; -- procedure oid for operator code
+ * procedureName; -- procedure name for operator code
* precedence; -- operator precedence
* isLeftAssociative; -- operator is left associative?
* commutatorName; -- X commutator operator name
* negatorName; -- X negator operator name
* restrictionName; -- X restriction sel. procedure name
* joinName; -- X join sel. procedure name
- * canHash; -- possible hash operator?
- * leftSortName; -- X left sort operator
- * rightSortName; -- X right sort operator
+ * canHash; -- can hash join be used with operator?
+ * leftSortName; -- X left sort operator (for merge join)
+ * rightSortName; -- X right sort operator (for merge join)
*/
static void
OperatorDef(char *operatorName,
- int definedOK,
char *leftTypeName,
char *rightTypeName,
char *procedureName,
char nulls[Natts_pg_operator];
char replaces[Natts_pg_operator];
Datum values[Natts_pg_operator];
- Oid other_oid = 0;
Oid operatorObjectId;
+ bool operatorAlreadyDefined;
Oid leftTypeId = InvalidOid;
Oid rightTypeId = InvalidOid;
Oid commutatorId = InvalidOid;
Oid negatorId = InvalidOid;
bool leftDefined = false;
bool rightDefined = false;
+ bool selfCommutator = false;
char *name[4];
Oid typeId[8];
int nargs;
operatorObjectId = OperatorGet(operatorName,
leftTypeName,
- rightTypeName);
+ rightTypeName,
+ &operatorAlreadyDefined);
- if (OidIsValid(operatorObjectId) && !definedOK)
+ if (operatorAlreadyDefined)
elog(ERROR, "OperatorDef: operator \"%s\" already defined",
operatorName);
+ /* At this point, if operatorObjectId is not InvalidOid then
+ * we are filling in a previously-created shell.
+ */
+
+ /* ----------------
+ * look up the operator data types.
+ *
+ * Note: types must be defined before operators
+ * ----------------
+ */
if (leftTypeName)
+ {
leftTypeId = TypeGet(leftTypeName, &leftDefined);
+ if (!OidIsValid(leftTypeId) || !leftDefined)
+ elog(ERROR, "OperatorDef: left type '%s' nonexistent",
+ leftTypeName);
+ }
+
if (rightTypeName)
+ {
rightTypeId = TypeGet(rightTypeName, &rightDefined);
- if (!((OidIsValid(leftTypeId && leftDefined)) ||
- (OidIsValid(rightTypeId && rightDefined))))
- elog(ERROR, "OperatorGet: no argument types??");
+ if (!OidIsValid(rightTypeId) || !rightDefined)
+ elog(ERROR, "OperatorDef: right type '%s' nonexistent",
+ rightTypeName);
+ }
+
+ if (!((OidIsValid(leftTypeId) && leftDefined) ||
+ (OidIsValid(rightTypeId) && rightDefined)))
+ elog(ERROR, "OperatorDef: must have at least one argument type");
for (i = 0; i < Natts_pg_operator; ++i)
{
values[i++] = ObjectIdGetDatum(leftTypeId);
values[i++] = ObjectIdGetDatum(rightTypeId);
- ++i; /* Skip "prorettype", this was done above */
+ ++i; /* Skip "oprresult", it was filled in above */
/*
- * Set up the other operators. If they do not currently exist, set up
- * shells in order to get ObjectId's and call OperatorDef again later
- * to fill in the shells.
+ * Set up the other operators. If they do not currently exist, create
+ * shells in order to get ObjectId's.
*/
name[0] = commutatorName;
name[1] = negatorName;
{
if (name[j])
{
-
- /* for the commutator, switch order of arguments */
- if (j == 0)
+ char *otherLeftTypeName = NULL;
+ char *otherRightTypeName = NULL;
+ Oid otherLeftTypeId = InvalidOid;
+ Oid otherRightTypeId = InvalidOid;
+ Oid other_oid = InvalidOid;
+ bool otherDefined = false;
+
+ switch (j)
{
- other_oid = OperatorGet(name[j], rightTypeName, leftTypeName);
- commutatorId = other_oid;
- }
- else
- {
- other_oid = OperatorGet(name[j], leftTypeName, rightTypeName);
- if (j == 1)
+ case 0: /* commutator has reversed arg types */
+ otherLeftTypeName = rightTypeName;
+ otherRightTypeName = leftTypeName;
+ otherLeftTypeId = rightTypeId;
+ otherRightTypeId = leftTypeId;
+ other_oid = OperatorGet(name[j],
+ otherLeftTypeName,
+ otherRightTypeName,
+ &otherDefined);
+ commutatorId = other_oid;
+ break;
+ case 1: /* negator has same arg types */
+ otherLeftTypeName = leftTypeName;
+ otherRightTypeName = rightTypeName;
+ otherLeftTypeId = leftTypeId;
+ otherRightTypeId = rightTypeId;
+ other_oid = OperatorGet(name[j],
+ otherLeftTypeName,
+ otherRightTypeName,
+ &otherDefined);
negatorId = other_oid;
+ break;
+ case 2: /* left sort op takes left-side data type */
+ otherLeftTypeName = leftTypeName;
+ otherRightTypeName = leftTypeName;
+ otherLeftTypeId = leftTypeId;
+ otherRightTypeId = leftTypeId;
+ other_oid = OperatorGet(name[j],
+ otherLeftTypeName,
+ otherRightTypeName,
+ &otherDefined);
+ break;
+ case 3: /* right sort op takes right-side data type */
+ otherLeftTypeName = rightTypeName;
+ otherRightTypeName = rightTypeName;
+ otherLeftTypeId = rightTypeId;
+ otherRightTypeId = rightTypeId;
+ other_oid = OperatorGet(name[j],
+ otherLeftTypeName,
+ otherRightTypeName,
+ &otherDefined);
+ break;
}
- if (OidIsValid(other_oid)) /* already in catalogs */
+ if (OidIsValid(other_oid))
+ {
+ /* other op already in catalogs */
values[i++] = ObjectIdGetDatum(other_oid);
- else if (strcmp(operatorName, name[j]) != 0)
+ }
+ else if (strcmp(operatorName, name[j]) != 0 ||
+ otherLeftTypeId != leftTypeId ||
+ otherRightTypeId != rightTypeId)
{
/* not in catalogs, different from operator */
-
- /* for the commutator, switch order of arguments */
- if (j == 0)
- {
- other_oid = OperatorShellMake(name[j],
- rightTypeName,
- leftTypeName);
- }
- else
- {
- other_oid = OperatorShellMake(name[j],
- leftTypeName,
- rightTypeName);
- }
-
+ other_oid = OperatorShellMake(name[j],
+ otherLeftTypeName,
+ otherRightTypeName);
if (!OidIsValid(other_oid))
elog(ERROR,
- "OperatorDef: can't create operator '%s'",
+ "OperatorDef: can't create operator shell '%s'",
name[j]);
values[i++] = ObjectIdGetDatum(other_oid);
-
}
else
-/* not in catalogs, same as operator ??? */
+ {
+ /* self-linkage to this operator; will fix below.
+ * Note that only self-linkage for commutation makes sense.
+ */
+ if (j != 0)
+ elog(ERROR,
+ "OperatorDef: operator can't be its own negator or sort op");
+ selfCommutator = true;
values[i++] = ObjectIdGetDatum(InvalidOid);
-
+ }
}
else
-/* new operator is optional */
+ {
+ /* other operator is omitted */
values[i++] = ObjectIdGetDatum(InvalidOid);
+ }
}
- /* last three fields were filled in first */
+ /* last three fields were filled in above */
/*
* If we are adding to an operator shell, get its t_self
setheapoverride(false);
}
else
- elog(ERROR, "OperatorDef: no operator %d", other_oid);
+ elog(ERROR, "OperatorDef: no operator %d", operatorObjectId);
heap_endscan(pg_operator_scan);
}
heap_close(pg_operator_desc);
/*
- * It's possible that we're creating a skeleton operator here for the
- * commute or negate attributes of a real operator. If we are, then
- * we're done. If not, we may need to update the negator and
- * commutator for this attribute. The reason for this is that the
- * user may want to create two operators (say < and >=). When he
- * defines <, if he uses >= as the negator or commutator, he won't be
- * able to insert it later, since (for some reason) define operator
- * defines it for him. So what he does is to define > without a
- * negator or commutator. Then he defines >= with < as the negator
- * and commutator. As a side effect, this will update the > tuple if
- * it has no commutator or negator defined.
- *
- * Alstublieft, Tom Vijlbrief.
+ * If a commutator and/or negator link is provided, update the other
+ * operator(s) to point at this one, if they don't already have a link.
+ * This supports an alternate style of operator definition wherein the
+ * user first defines one operator without giving negator or
+ * commutator, then defines the other operator of the pair with the
+ * proper commutator or negator attribute. That style doesn't require
+ * creation of a shell, and it's the only style that worked right before
+ * Postgres version 6.5.
+ * This code also takes care of the situation where the new operator
+ * is its own commutator.
*/
- if (!definedOK)
+ if (selfCommutator)
+ commutatorId = operatorObjectId;
+
+ if (OidIsValid(commutatorId) || OidIsValid(negatorId))
OperatorUpd(operatorObjectId, commutatorId, negatorId);
}
* OperatorUpd
*
* For a given operator, look up its negator and commutator operators.
- * If they are defined, but their negator and commutator operators
- * (respectively) are not, then use the new operator for neg and comm.
+ * If they are defined, but their negator and commutator fields
+ * (respectively) are empty, then use the new operator for neg or comm.
* This solves a problem for users who need to insert two new operators
* which are the negator or commutator of each other.
* ----------------------------------------------------------------
tup = heap_getnext(pg_operator_scan, 0);
- /* if the commutator and negator are the same operator, do one update */
+ /* if the commutator and negator are the same operator, do one update.
+ * XXX this is probably useless code --- I doubt it ever makes sense
+ * for commutator and negator to be the same thing...
+ */
if (commId == negId)
{
if (HeapTupleIsValid(tup))
/* ----------------------------------------------------------------
* OperatorCreate
*
- * Algorithm:
- *
- * Since the commutator, negator, leftsortoperator, and rightsortoperator
- * can be defined implicitly through OperatorCreate, must check before
- * the main operator is added to see if they already exist. If they
- * do not already exist, OperatorDef makes a "shell" for each undefined
- * one, and then OperatorCreate must call OperatorDef again to fill in
- * each shell. All this is necessary in order to get the right ObjectId's
- * filled into the right fields.
- *
- * The "definedOk" flag indicates that OperatorDef can be called on
- * the operator even though it already has an entry in the PG_OPERATOR
- * relation. This allows shells to be filled in. The user cannot
- * forward declare operators, this is strictly an internal capability.
- *
- * When the shells are filled in by subsequent calls to OperatorDef,
- * all the fields are the same as the definition of the original operator
- * except that the target operator name and the original operatorName
- * are switched. In the case of commutator and negator, special flags
- * are set to indicate their status, telling the executor(?) that
- * the operands are to be switched, or the outcome of the procedure
- * negated.
- *
- * ************************* NOTE NOTE NOTE ******************************
- *
- * If the execution of this utility is interrupted, the pg_operator
- * catalog may be left in an inconsistent state. Similarly, if
- * something is removed from the pg_operator, pg_type, or pg_procedure
- * catalog while this is executing, the results may be inconsistent.
- * ----------------------------------------------------------------
+ * This is now just an interface procedure for OperatorDef ...
*
* "X" indicates an optional argument (i.e. one that can be NULL)
* operatorName; -- operator name
* commutatorName; -- X commutator operator name
* negatorName; -- X negator operator name
* restrictionName; -- X restriction sel. procedure
- * joinName; -- X join sel. procedure name
- * canHash; -- operator hashes
- * leftSortName; -- X left sort operator
- * rightSortName; -- X right sort operator
- *
+ * joinName; -- X join sel. procedure
+ * canHash; -- hash join can be used with this operator
+ * leftSortName; -- X left sort operator (for merge join)
+ * rightSortName; -- X right sort operator (for merge join)
*/
void
OperatorCreate(char *operatorName,
char *leftSortName,
char *rightSortName)
{
- Oid commObjectId,
- negObjectId;
- Oid leftSortObjectId,
- rightSortObjectId;
- int definedOK;
-
if (!leftTypeName && !rightTypeName)
- elog(ERROR, "OperatorCreate : at least one of leftarg or rightarg must be defined");
+ elog(ERROR, "OperatorCreate: at least one of leftarg or rightarg must be defined");
- /* ----------------
- * get the oid's of the operator's associated operators, if possible.
- * ----------------
- */
- if (commutatorName)
- commObjectId = OperatorGet(commutatorName, /* commute type order */
- rightTypeName,
- leftTypeName);
- else
- commObjectId = 0;
-
- if (negatorName)
- negObjectId = OperatorGet(negatorName,
- leftTypeName,
- rightTypeName);
- else
- negObjectId = 0;
-
- if (leftSortName)
- leftSortObjectId = OperatorGet(leftSortName,
- leftTypeName,
- rightTypeName);
- else
- leftSortObjectId = 0;
-
- if (rightSortName)
- rightSortObjectId = OperatorGet(rightSortName,
- rightTypeName,
- leftTypeName);
- else
- rightSortObjectId = 0;
+ if (! (leftTypeName && rightTypeName))
+ {
+ /* If it's not a binary op, these things mustn't be set: */
+ if (commutatorName)
+ elog(ERROR, "OperatorCreate: only binary operators can have commutators");
+ if (negatorName)
+ elog(ERROR, "OperatorCreate: only binary operators can have negators");
+ if (restrictionName || joinName)
+ elog(ERROR, "OperatorCreate: only binary operators can have selectivity");
+ if (canHash)
+ elog(ERROR, "OperatorCreate: only binary operators can hash");
+ if (leftSortName || rightSortName)
+ elog(ERROR, "OperatorCreate: only binary operators can have sort links");
+ }
/* ----------------
* Use OperatorDef() to define the specified operator and
* also create shells for the operator's associated operators
* if they don't already exist.
- *
- * This operator should not be defined yet.
* ----------------
*/
- definedOK = 0;
-
OperatorDef(operatorName,
- definedOK,
leftTypeName,
rightTypeName,
procedureName,
canHash,
leftSortName,
rightSortName);
-
- /* ----------------
- * Now fill in information in the operator's associated
- * operators.
- *
- * These operators should be defined or have shells defined.
- * ----------------
- */
- definedOK = 1;
-
- if (!OidIsValid(commObjectId) && commutatorName)
- OperatorDef(commutatorName,
- definedOK,
- leftTypeName, /* should eventually */
- rightTypeName, /* commute order */
- procedureName,
- precedence,
- isLeftAssociative,
- operatorName, /* commutator */
- negatorName,
- restrictionName,
- joinName,
- canHash,
- rightSortName,
- leftSortName);
-
- if (negatorName && !OidIsValid(negObjectId))
- OperatorDef(negatorName,
- definedOK,
- leftTypeName,
- rightTypeName,
- procedureName,
- precedence,
- isLeftAssociative,
- commutatorName,
- operatorName, /* negator */
- restrictionName,
- joinName,
- canHash,
- leftSortName,
- rightSortName);
-
- if (leftSortName && !OidIsValid(leftSortObjectId))
- OperatorDef(leftSortName,
- definedOK,
- leftTypeName,
- rightTypeName,
- procedureName,
- precedence,
- isLeftAssociative,
- commutatorName,
- negatorName,
- restrictionName,
- joinName,
- canHash,
- operatorName, /* left sort */
- rightSortName);
-
- if (rightSortName && !OidIsValid(rightSortObjectId))
- OperatorDef(rightSortName,
- definedOK,
- leftTypeName,
- rightTypeName,
- procedureName,
- precedence,
- isLeftAssociative,
- commutatorName,
- negatorName,
- restrictionName,
- joinName,
- canHash,
- leftSortName,
- operatorName); /* right sort */
}
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