]> git.ipfire.org Git - thirdparty/postgresql.git/commitdiff
Repair failure to check that a table is still compatible with a previously
authorTom Lane <tgl@sss.pgh.pa.us>
Fri, 2 Feb 2007 00:07:44 +0000 (00:07 +0000)
committerTom Lane <tgl@sss.pgh.pa.us>
Fri, 2 Feb 2007 00:07:44 +0000 (00:07 +0000)
made query plan.  Use of ALTER COLUMN TYPE creates a hazard for cached
query plans: they could contain Vars that claim a column has a different
type than it now has.  Fix this by checking during plan startup that Vars
at relation scan level match the current relation tuple descriptor.  Since
at that point we already have at least AccessShareLock, we can be sure the
column type will not change underneath us later in the query.  However,
since a backend's locks do not conflict against itself, there is still a
hole for an attacker to exploit: he could try to execute ALTER COLUMN TYPE
while a query is in progress in the current backend.  Seal that hole by
rejecting ALTER TABLE whenever the target relation is already open in
the current backend.

This is a significant security hole: not only can one trivially crash the
backend, but with appropriate misuse of pass-by-reference datatypes it is
possible to read out arbitrary locations in the server process's memory,
which could allow retrieving database content the user should not be able
to see.  Our thanks to Jeff Trout for the initial report.

Security: CVE-2007-0556

12 files changed:
src/backend/commands/tablecmds.c
src/backend/executor/execQual.c
src/backend/executor/execScan.c
src/backend/executor/execUtils.c
src/backend/executor/nodeAgg.c
src/backend/executor/nodeGroup.c
src/backend/executor/nodeHashjoin.c
src/backend/executor/nodeMergejoin.c
src/backend/executor/nodeNestloop.c
src/backend/executor/nodeResult.c
src/backend/executor/nodeSubplan.c
src/include/executor/executor.h

index e8e2f4e36085be23ee4964ea7991aa1b20ca3e4e..04a3dc632a5389ae6c02e8f907b087ad578d297c 100644 (file)
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.174.2.3 2006/07/10 22:10:47 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.174.2.4 2007/02/02 00:07:44 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1799,22 +1799,47 @@ update_ri_trigger_args(Oid relid,
 void
 AlterTable(AlterTableStmt *stmt)
 {
-       ATController(relation_openrv(stmt->relation, AccessExclusiveLock),
-                                stmt->cmds,
-                                interpretInhOption(stmt->relation->inhOpt));
+       Relation rel = relation_openrv(stmt->relation, AccessExclusiveLock);
+       int                     expected_refcnt;
+
+       /*
+        * Disallow ALTER TABLE when the current backend has any open reference
+        * to it besides the one we just got (such as an open cursor or active
+        * plan); our AccessExclusiveLock doesn't protect us against stomping on
+        * our own foot, only other people's feet!
+        *
+        * Note: the only case known to cause serious trouble is ALTER COLUMN TYPE,
+        * and some changes are obviously pretty benign, so this could possibly
+        * be relaxed to only error out for certain types of alterations.  But
+        * the use-case for allowing any of these things is not obvious, so we
+        * won't work hard at it for now.
+        */
+       expected_refcnt = rel->rd_isnailed ? 2 : 1;
+       if (rel->rd_refcnt != expected_refcnt)
+               ereport(ERROR,
+                               (errcode(ERRCODE_OBJECT_IN_USE),
+                                errmsg("relation \"%s\" is being used by active queries in this session",
+                                               RelationGetRelationName(rel))));
+
+       ATController(rel, stmt->cmds, interpretInhOption(stmt->relation->inhOpt));
 }
 
 /*
  * AlterTableInternal
  *
  * ALTER TABLE with target specified by OID
+ *
+ * We do not reject if the relation is already open, because it's quite
+ * likely that one or more layers of caller have it open.  That means it
+ * is unsafe to use this entry point for alterations that could break
+ * existing query plans.
  */
 void
 AlterTableInternal(Oid relid, List *cmds, bool recurse)
 {
-       ATController(relation_open(relid, AccessExclusiveLock),
-                                cmds,
-                                recurse);
+       Relation rel = relation_open(relid, AccessExclusiveLock);
+
+       ATController(rel, cmds, recurse);
 }
 
 static void
@@ -2719,6 +2744,12 @@ ATSimpleRecursion(List **wqueue, Relation rel,
                        if (childrelid == relid)
                                continue;
                        childrel = relation_open(childrelid, AccessExclusiveLock);
+                       /* check for child relation in use in this session */
+                       if (childrel->rd_refcnt != 1)
+                               ereport(ERROR,
+                                               (errcode(ERRCODE_OBJECT_IN_USE),
+                                                errmsg("relation \"%s\" is being used by active queries in this session",
+                                                               RelationGetRelationName(childrel))));
                        ATPrepCmd(wqueue, childrel, cmd, false, true);
                        relation_close(childrel, NoLock);
                }
@@ -2750,6 +2781,12 @@ ATOneLevelRecursion(List **wqueue, Relation rel,
                Relation        childrel;
 
                childrel = relation_open(childrelid, AccessExclusiveLock);
+               /* check for child relation in use in this session */
+               if (childrel->rd_refcnt != 1)
+                       ereport(ERROR,
+                                       (errcode(ERRCODE_OBJECT_IN_USE),
+                                        errmsg("relation \"%s\" is being used by active queries in this session",
+                                                       RelationGetRelationName(childrel))));
                ATPrepCmd(wqueue, childrel, cmd, true, true);
                relation_close(childrel, NoLock);
        }
@@ -3571,6 +3608,12 @@ ATExecDropColumn(Relation rel, const char *colName,
                        Form_pg_attribute childatt;
 
                        childrel = heap_open(childrelid, AccessExclusiveLock);
+                       /* check for child relation in use in this session */
+                       if (childrel->rd_refcnt != 1)
+                               ereport(ERROR,
+                                               (errcode(ERRCODE_OBJECT_IN_USE),
+                                                errmsg("relation \"%s\" is being used by active queries in this session",
+                                                               RelationGetRelationName(childrel))));
 
                        tuple = SearchSysCacheCopyAttName(childrelid, colName);
                        if (!HeapTupleIsValid(tuple))           /* shouldn't happen */
index e21aba888f14e92441ef065dedeeed51752dc110..e063814aad9afd1abe0e12de74b88676da0688bb 100644 (file)
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/executor/execQual.c,v 1.183.2.4 2006/11/06 18:21:38 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/executor/execQual.c,v 1.183.2.5 2007/02/02 00:07:44 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -64,6 +64,8 @@ static Datum ExecEvalAggref(AggrefExprState *aggref,
                           bool *isNull, ExprDoneCond *isDone);
 static Datum ExecEvalVar(ExprState *exprstate, ExprContext *econtext,
                        bool *isNull, ExprDoneCond *isDone);
+static Datum ExecEvalScalarVar(ExprState *exprstate, ExprContext *econtext,
+                       bool *isNull, ExprDoneCond *isDone);
 static Datum ExecEvalWholeRowVar(ExprState *exprstate, ExprContext *econtext,
                                        bool *isNull, ExprDoneCond *isDone);
 static Datum ExecEvalConst(ExprState *exprstate, ExprContext *econtext,
@@ -434,6 +436,10 @@ ExecEvalAggref(AggrefExprState *aggref, ExprContext *econtext,
  *
  *             Returns a Datum whose value is the value of a range
  *             variable with respect to given expression context.
+ *
+ * Note: ExecEvalVar is executed only the first time through in a given plan;
+ * it changes the ExprState's function pointer to pass control directly to
+ * ExecEvalScalarVar or ExecEvalWholeRowVar after making one-time checks.
  * ----------------------------------------------------------------
  */
 static Datum
@@ -448,7 +454,7 @@ ExecEvalVar(ExprState *exprstate, ExprContext *econtext,
                *isDone = ExprSingleResult;
 
        /*
-        * Get the slot and attribute number we want
+        * Get the input slot and attribute number we want
         *
         * The asserts check that references to system attributes only appear at
         * the level of a relation scan; at higher levels, system attributes must
@@ -475,35 +481,168 @@ ExecEvalVar(ExprState *exprstate, ExprContext *econtext,
                        break;
        }
 
-#ifdef USE_ASSERT_CHECKING
-
-       /*
-        * Some checks that are only applied for user attribute numbers (bogus
-        * system attnums will be caught inside slot_getattr).
-        */
-       if (attnum > 0)
+       if (attnum != InvalidAttrNumber)
        {
-               TupleDesc       tuple_type = slot->tts_tupleDescriptor;
-
                /*
-                * This assert checks that the attnum is valid.
+                * Scalar variable case.
+                *
+                * If it's a user attribute, check validity (bogus system attnums will
+                * be caught inside slot_getattr).  What we have to check for here
+                * is the possibility of an attribute having been changed in type
+                * since the plan tree was created.  Ideally the plan would get
+                * invalidated and not re-used, but until that day arrives, we need
+                * defenses.  Fortunately it's sufficient to check once on the first
+                * time through.
+                *
+                * Note: we allow a reference to a dropped attribute.  slot_getattr
+                * will force a NULL result in such cases.
+                *
+                * Note: we check typmod, but allow the case that the Var has
+                * unspecified typmod while the column has a specific typmod.
                 */
-               Assert(attnum <= tuple_type->natts);
+               if (attnum > 0)
+               {
+                       TupleDesc       slot_tupdesc = slot->tts_tupleDescriptor;
+                       Form_pg_attribute attr;
+
+                       if (attnum > slot_tupdesc->natts)       /* should never happen */
+                               elog(ERROR, "attribute number %d exceeds number of columns %d",
+                                        attnum, slot_tupdesc->natts);
+
+                       attr = slot_tupdesc->attrs[attnum - 1];
 
+                       /* can't check type if dropped, since atttypid is probably 0 */
+                       if (!attr->attisdropped)
+                       {
+                               if (variable->vartype != attr->atttypid ||
+                                       (variable->vartypmod != attr->atttypmod &&
+                                        variable->vartypmod != -1))
+                                       ereport(ERROR,
+                                                       (errmsg("attribute %d has wrong type", attnum),
+                                                        errdetail("Table has type %s, but query expects %s.",
+                                                                          format_type_be(attr->atttypid),
+                                                                          format_type_be(variable->vartype))));
+                       }
+               }
+
+               /* Skip the checking on future executions of node */
+               exprstate->evalfunc = ExecEvalScalarVar;
+
+               /* Fetch the value from the slot */
+               return slot_getattr(slot, attnum, isNull);
+       }
+       else
+       {
                /*
-                * This assert checks that the datatype the plan expects to get (as
-                * told by our "variable" argument) is in fact the datatype of the
-                * attribute being fetched (as seen in the current context, identified
-                * by our "econtext" argument).  Otherwise crashes are likely.
+                * Whole-row variable.
                 *
-                * Note that we can't check dropped columns, since their atttypid has
-                * been zeroed.
+                * If it's a RECORD Var, we'll use the slot's type ID info.  It's
+                * likely that the slot's type is also RECORD; if so, make sure it's
+                * been "blessed", so that the Datum can be interpreted later.
+                *
+                * If the Var identifies a named composite type, we must check that
+                * the actual tuple type is compatible with it.
                 */
-               Assert(variable->vartype == tuple_type->attrs[attnum - 1]->atttypid ||
-                          tuple_type->attrs[attnum - 1]->attisdropped);
+               TupleDesc       slot_tupdesc = slot->tts_tupleDescriptor;
+
+               if (variable->vartype == RECORDOID)
+               {
+                       if (slot_tupdesc->tdtypeid == RECORDOID &&
+                               slot_tupdesc->tdtypmod < 0)
+                               assign_record_type_typmod(slot_tupdesc);
+               }
+               else
+               {
+                       TupleDesc       var_tupdesc;
+                       int                     i;
+
+                       /*
+                        * We really only care about number of attributes and data type.
+                        * Also, we can ignore type mismatch on columns that are dropped
+                        * in the destination type, so long as the physical storage
+                        * matches.  This is helpful in some cases involving out-of-date
+                        * cached plans.
+                        */
+                       var_tupdesc = lookup_rowtype_tupdesc(variable->vartype, -1);
+
+                       if (var_tupdesc->natts != slot_tupdesc->natts)
+                               ereport(ERROR,
+                                               (errcode(ERRCODE_DATATYPE_MISMATCH),
+                                                errmsg("table row type and query-specified row type do not match"),
+                                                errdetail("Table row contains %d attributes, but query expects %d.",
+                                                                  slot_tupdesc->natts, var_tupdesc->natts)));
+
+                       for (i = 0; i < var_tupdesc->natts; i++)
+                       {
+                               Form_pg_attribute vattr = var_tupdesc->attrs[i];
+                               Form_pg_attribute sattr = slot_tupdesc->attrs[i];
+
+                               if (vattr->atttypid == sattr->atttypid)
+                                       continue;                       /* no worries */
+                               if (!vattr->attisdropped)
+                                       ereport(ERROR,
+                                                       (errcode(ERRCODE_DATATYPE_MISMATCH),
+                                                        errmsg("table row type and query-specified row type do not match"),
+                                                        errdetail("Table has type %s at ordinal position %d, but query expects %s.",
+                                                                          format_type_be(sattr->atttypid),
+                                                                          i + 1,
+                                                                          format_type_be(vattr->atttypid))));
+
+                               if (vattr->attlen != sattr->attlen ||
+                                       vattr->attalign != sattr->attalign)
+                                       ereport(ERROR,
+                                                       (errcode(ERRCODE_DATATYPE_MISMATCH),
+                                                        errmsg("table row type and query-specified row type do not match"),
+                                                        errdetail("Physical storage mismatch on dropped attribute at ordinal position %d.",
+                                                                          i + 1)));
+                       }
+               }
+
+               /* Skip the checking on future executions of node */
+               exprstate->evalfunc = ExecEvalWholeRowVar;
+
+               /* Fetch the value */
+               return ExecEvalWholeRowVar(exprstate, econtext, isNull, isDone);
+       }
+}
+
+/* ----------------------------------------------------------------
+ *             ExecEvalScalarVar
+ *
+ *             Returns a Datum for a scalar variable.
+ * ----------------------------------------------------------------
+ */
+static Datum
+ExecEvalScalarVar(ExprState *exprstate, ExprContext *econtext,
+                                 bool *isNull, ExprDoneCond *isDone)
+{
+       Var                *variable = (Var *) exprstate->expr;
+       TupleTableSlot *slot;
+       AttrNumber      attnum;
+
+       if (isDone)
+               *isDone = ExprSingleResult;
+
+       /* Get the input slot and attribute number we want */
+       switch (variable->varno)
+       {
+               case INNER:                             /* get the tuple from the inner node */
+                       slot = econtext->ecxt_innertuple;
+                       break;
+
+               case OUTER:                             /* get the tuple from the outer node */
+                       slot = econtext->ecxt_outertuple;
+                       break;
+
+               default:                                /* get the tuple from the relation being
+                                                                * scanned */
+                       slot = econtext->ecxt_scantuple;
+                       break;
        }
-#endif   /* USE_ASSERT_CHECKING */
 
+       attnum = variable->varattno;
+
+       /* Fetch the value from the slot */
        return slot_getattr(slot, attnum, isNull);
 }
 
@@ -511,10 +650,6 @@ ExecEvalVar(ExprState *exprstate, ExprContext *econtext,
  *             ExecEvalWholeRowVar
  *
  *             Returns a Datum for a whole-row variable.
- *
- *             This could be folded into ExecEvalVar, but we make it a separate
- *             routine so as not to slow down ExecEvalVar with tests for this
- *             uncommon case.
  * ----------------------------------------------------------------
  */
 static Datum
@@ -522,7 +657,7 @@ ExecEvalWholeRowVar(ExprState *exprstate, ExprContext *econtext,
                                        bool *isNull, ExprDoneCond *isDone)
 {
        Var                *variable = (Var *) exprstate->expr;
-       TupleTableSlot *slot;
+       TupleTableSlot *slot = econtext->ecxt_scantuple;
        HeapTuple       tuple;
        TupleDesc       tupleDesc;
        HeapTupleHeader dtuple;
@@ -531,16 +666,6 @@ ExecEvalWholeRowVar(ExprState *exprstate, ExprContext *econtext,
                *isDone = ExprSingleResult;
        *isNull = false;
 
-       Assert(variable->varattno == InvalidAttrNumber);
-
-       /*
-        * Whole-row Vars can only appear at the level of a relation scan, never
-        * in a join.
-        */
-       Assert(variable->varno != INNER);
-       Assert(variable->varno != OUTER);
-       slot = econtext->ecxt_scantuple;
-
        tuple = ExecFetchSlotTuple(slot);
        tupleDesc = slot->tts_tupleDescriptor;
 
@@ -556,9 +681,6 @@ ExecEvalWholeRowVar(ExprState *exprstate, ExprContext *econtext,
        /*
         * If the Var identifies a named composite type, label the tuple with that
         * type; otherwise use what is in the tupleDesc.
-        *
-        * It's likely that the slot's tupleDesc is a record type; if so, make
-        * sure it's been "blessed", so that the Datum can be interpreted later.
         */
        if (variable->vartype != RECORDOID)
        {
@@ -567,9 +689,6 @@ ExecEvalWholeRowVar(ExprState *exprstate, ExprContext *econtext,
        }
        else
        {
-               if (tupleDesc->tdtypeid == RECORDOID &&
-                       tupleDesc->tdtypmod < 0)
-                       assign_record_type_typmod(tupleDesc);
                HeapTupleHeaderSetTypeId(dtuple, tupleDesc->tdtypeid);
                HeapTupleHeaderSetTypMod(dtuple, tupleDesc->tdtypmod);
        }
@@ -2700,12 +2819,14 @@ ExecEvalFieldSelect(FieldSelectState *fstate,
                                        ExprDoneCond *isDone)
 {
        FieldSelect *fselect = (FieldSelect *) fstate->xprstate.expr;
+       AttrNumber      fieldnum = fselect->fieldnum;
        Datum           result;
        Datum           tupDatum;
        HeapTupleHeader tuple;
        Oid                     tupType;
        int32           tupTypmod;
        TupleDesc       tupDesc;
+       Form_pg_attribute attr;
        HeapTupleData tmptup;
 
        tupDatum = ExecEvalExpr(fstate->arg, econtext, isNull, isDone);
@@ -2737,6 +2858,28 @@ ExecEvalFieldSelect(FieldSelectState *fstate,
                MemoryContextSwitchTo(oldcontext);
        }
 
+       /* Check for dropped column, and force a NULL result if so */
+       if (fieldnum <= 0 ||
+               fieldnum > tupDesc->natts)      /* should never happen */
+                               elog(ERROR, "attribute number %d exceeds number of columns %d",
+                                        fieldnum, tupDesc->natts);
+       attr = tupDesc->attrs[fieldnum - 1];
+       if (attr->attisdropped)
+       {
+               *isNull = true;
+               return (Datum) 0;
+       }
+
+       /* Check for type mismatch --- possible after ALTER COLUMN TYPE? */
+       if (fselect->resulttype != attr->atttypid ||
+               (fselect->resulttypmod != attr->atttypmod &&
+                fselect->resulttypmod != -1))
+               ereport(ERROR,
+                               (errmsg("attribute %d has wrong type", fieldnum),
+                                errdetail("Table has type %s, but query expects %s.",
+                                                  format_type_be(attr->atttypid),
+                                                  format_type_be(fselect->resulttype))));
+
        /*
         * heap_getattr needs a HeapTuple not a bare HeapTupleHeader.  We set all
         * the fields in the struct just in case user tries to inspect system
@@ -2748,7 +2891,7 @@ ExecEvalFieldSelect(FieldSelectState *fstate,
        tmptup.t_data = tuple;
 
        result = heap_getattr(&tmptup,
-                                                 fselect->fieldnum,
+                                                 fieldnum,
                                                  tupDesc,
                                                  isNull);
        return result;
@@ -2948,15 +3091,8 @@ ExecInitExpr(Expr *node, PlanState *parent)
        switch (nodeTag(node))
        {
                case T_Var:
-                       {
-                               Var                *var = (Var *) node;
-
-                               state = (ExprState *) makeNode(ExprState);
-                               if (var->varattno != InvalidAttrNumber)
-                                       state->evalfunc = ExecEvalVar;
-                               else
-                                       state->evalfunc = ExecEvalWholeRowVar;
-                       }
+                       state = (ExprState *) makeNode(ExprState);
+                       state->evalfunc = ExecEvalVar;
                        break;
                case T_Const:
                        state = (ExprState *) makeNode(ExprState);
index 45ef7c3ef8272c8fa6a524cdf58eab34647f574d..1154b785447080fd8c3aeb64f2b1113b96b73c34 100644 (file)
@@ -12,7 +12,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/executor/execScan.c,v 1.37.2.1 2007/01/24 01:25:56 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/executor/execScan.c,v 1.37.2.2 2007/02/02 00:07:44 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -187,7 +187,8 @@ ExecAssignScanProjectionInfo(ScanState *node)
                                                          node->ss_ScanTupleSlot->tts_tupleDescriptor))
                node->ps.ps_ProjInfo = NULL;
        else
-               ExecAssignProjectionInfo(&node->ps);
+               ExecAssignProjectionInfo(&node->ps,
+                                                                node->ss_ScanTupleSlot->tts_tupleDescriptor);
 }
 
 static bool
@@ -209,6 +210,7 @@ tlist_matches_tupdesc(PlanState *ps, List *tlist, Index varno, TupleDesc tupdesc
                var = (Var *) ((TargetEntry *) lfirst(tlist_item))->expr;
                if (!var || !IsA(var, Var))
                        return false;           /* tlist item not a Var */
+               /* if these Asserts fail, planner messed up */
                Assert(var->varno == varno);
                Assert(var->varlevelsup == 0);
                if (var->varattno != attrno)
@@ -225,8 +227,10 @@ tlist_matches_tupdesc(PlanState *ps, List *tlist, Index varno, TupleDesc tupdesc
                 * projection steps just to convert from specific typmod to typmod -1,
                 * which is pretty silly.
                 */
-               Assert(var->vartype == att_tup->atttypid);
-               Assert(var->vartypmod == att_tup->atttypmod || var->vartypmod == -1);
+               if (var->vartype != att_tup->atttypid ||
+                       (var->vartypmod != att_tup->atttypmod &&
+                        var->vartypmod != -1))
+                       return false;           /* type mismatch */
 
                tlist_item = lnext(tlist_item);
        }
index 5983249bba258fd3b764627a46ee731b72468458..a2d3543ced0352ddbfc7cbab85b09acf2ac5bcbb 100644 (file)
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/executor/execUtils.c,v 1.126.2.3 2005/11/23 20:28:04 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/executor/execUtils.c,v 1.126.2.4 2007/02/02 00:07:44 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -483,12 +483,19 @@ ExecGetResultType(PlanState *planstate)
  * econtext, and storing the result into the tuple slot.  (Caller must have
  * ensured that tuple slot has a descriptor matching the tlist!)  Note that
  * the given tlist should be a list of ExprState nodes, not Expr nodes.
+ *
+ * inputDesc can be NULL, but if it is not, we check to see whether simple
+ * Vars in the tlist match the descriptor.  It is important to provide
+ * inputDesc for relation-scan plan nodes, as a cross check that the relation
+ * hasn't been changed since the plan was made.  At higher levels of a plan,
+ * there is no need to recheck.
  * ----------------
  */
 ProjectionInfo *
 ExecBuildProjectionInfo(List *targetList,
                                                ExprContext *econtext,
-                                               TupleTableSlot *slot)
+                                               TupleTableSlot *slot,
+                                               TupleDesc inputDesc)
 {
        ProjectionInfo *projInfo = makeNode(ProjectionInfo);
        int                     len;
@@ -503,14 +510,17 @@ ExecBuildProjectionInfo(List *targetList,
 
        /*
         * Determine whether the target list consists entirely of simple Var
-        * references (ie, references to non-system attributes).  If so, we can
-        * use the simpler ExecVariableList instead of ExecTargetList.
+        * references (ie, references to non-system attributes) that match the
+        * input.  If so, we can use the simpler ExecVariableList instead of
+        * ExecTargetList.  (Note: if there is a type mismatch then ExecEvalVar
+        * will probably throw an error at runtime, but we leave that to it.)
         */
        isVarList = true;
        foreach(tl, targetList)
        {
                GenericExprState *gstate = (GenericExprState *) lfirst(tl);
                Var                *variable = (Var *) gstate->arg->expr;
+               Form_pg_attribute attr;
 
                if (variable == NULL ||
                        !IsA(variable, Var) ||
@@ -519,6 +529,22 @@ ExecBuildProjectionInfo(List *targetList,
                        isVarList = false;
                        break;
                }
+               if (!inputDesc)
+                       continue;                       /* can't check type, assume OK */
+               if (variable->varattno > inputDesc->natts)
+               {
+                       isVarList = false;
+                       break;
+               }
+               attr = inputDesc->attrs[variable->varattno - 1];
+               if (attr->attisdropped ||
+                       variable->vartype != attr->atttypid ||
+                       (variable->vartypmod != attr->atttypmod &&
+                        variable->vartypmod != -1))
+               {
+                       isVarList = false;
+                       break;
+               }
        }
        projInfo->pi_isVarList = isVarList;
 
@@ -594,15 +620,20 @@ ExecBuildProjectionInfo(List *targetList,
  *             ExecAssignProjectionInfo
  *
  * forms the projection information from the node's targetlist
+ *
+ * Notes for inputDesc are same as for ExecBuildProjectionInfo: supply it
+ * for a relation-scan node, can pass NULL for upper-level nodes
  * ----------------
  */
 void
-ExecAssignProjectionInfo(PlanState *planstate)
+ExecAssignProjectionInfo(PlanState *planstate,
+                                                TupleDesc inputDesc)
 {
        planstate->ps_ProjInfo =
                ExecBuildProjectionInfo(planstate->targetlist,
                                                                planstate->ps_ExprContext,
-                                                               planstate->ps_ResultTupleSlot);
+                                                               planstate->ps_ResultTupleSlot,
+                                                               inputDesc);
 }
 
 
index 014219a1051f30751df05c10cba064923c21c461..c5c9aed7e78472057470ccefc427660cae5fba66 100644 (file)
@@ -61,7 +61,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/executor/nodeAgg.c,v 1.135.2.1 2005/11/22 18:23:09 momjian Exp $
+ *       $PostgreSQL: pgsql/src/backend/executor/nodeAgg.c,v 1.135.2.2 2007/02/02 00:07:44 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1120,7 +1120,7 @@ ExecInitAgg(Agg *node, EState *estate)
         * Initialize result tuple type and projection info.
         */
        ExecAssignResultTypeFromTL(&aggstate->ss.ps);
-       ExecAssignProjectionInfo(&aggstate->ss.ps);
+       ExecAssignProjectionInfo(&aggstate->ss.ps, NULL);
 
        /*
         * get the count of aggregates in targetlist and quals
index 91a08add4d9653c10f9b289f963be2b83b233718..0a691b61231c55520d9ccc512c72091a5f655d6f 100644 (file)
@@ -15,7 +15,7 @@
  *       locate group boundaries.
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/executor/nodeGroup.c,v 1.62 2005/10/15 02:49:17 momjian Exp $
+ *       $PostgreSQL: pgsql/src/backend/executor/nodeGroup.c,v 1.62.2.1 2007/02/02 00:07:44 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -203,7 +203,7 @@ ExecInitGroup(Group *node, EState *estate)
         * Initialize result tuple type and projection info.
         */
        ExecAssignResultTypeFromTL(&grpstate->ss.ps);
-       ExecAssignProjectionInfo(&grpstate->ss.ps);
+       ExecAssignProjectionInfo(&grpstate->ss.ps, NULL);
 
        /*
         * Precompute fmgr lookup data for inner loop
index 4b82c7fcea80add776aa6daf8a554eb3ccd09f21..22a13288661346450aaccdd318def390fc2bdf64 100644 (file)
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/executor/nodeHashjoin.c,v 1.75.2.3 2005/11/28 23:46:24 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/executor/nodeHashjoin.c,v 1.75.2.4 2007/02/02 00:07:44 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -426,7 +426,7 @@ ExecInitHashJoin(HashJoin *node, EState *estate)
         * initialize tuple type and projection info
         */
        ExecAssignResultTypeFromTL(&hjstate->js.ps);
-       ExecAssignProjectionInfo(&hjstate->js.ps);
+       ExecAssignProjectionInfo(&hjstate->js.ps, NULL);
 
        ExecSetSlotDescriptor(hjstate->hj_OuterTupleSlot,
                                                  ExecGetResultType(outerPlanState(hjstate)),
index dfa3c2e29aff14e97863e384f7279cd98d07017c..41b1e15a6a2b3b5c5b6dc83f1132b8759abc761a 100644 (file)
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/executor/nodeMergejoin.c,v 1.75.2.2 2006/03/17 19:38:20 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/executor/nodeMergejoin.c,v 1.75.2.3 2007/02/02 00:07:44 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1606,7 +1606,7 @@ ExecInitMergeJoin(MergeJoin *node, EState *estate)
         * initialize tuple type and projection info
         */
        ExecAssignResultTypeFromTL(&mergestate->js.ps);
-       ExecAssignProjectionInfo(&mergestate->js.ps);
+       ExecAssignProjectionInfo(&mergestate->js.ps, NULL);
 
        /*
         * preprocess the merge clauses
index 24f3621bb991a07ad8c482158ed392d02a38d845..16bf1b7934fdc6bf71d34ab4d3433fd0a5a68c1e 100644 (file)
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/executor/nodeNestloop.c,v 1.39.2.1 2005/11/22 18:23:09 momjian Exp $
+ *       $PostgreSQL: pgsql/src/backend/executor/nodeNestloop.c,v 1.39.2.2 2007/02/02 00:07:44 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -339,7 +339,7 @@ ExecInitNestLoop(NestLoop *node, EState *estate)
         * initialize tuple type and projection info
         */
        ExecAssignResultTypeFromTL(&nlstate->js.ps);
-       ExecAssignProjectionInfo(&nlstate->js.ps);
+       ExecAssignProjectionInfo(&nlstate->js.ps, NULL);
 
        /*
         * finally, wipe the current outer tuple clean.
index 952745783b30cf60d4e5844c7542468eb9505533..6f29d7450793d53e5dfd1fe80f75e7a2a56d2acf 100644 (file)
@@ -38,7 +38,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/executor/nodeResult.c,v 1.32.2.1 2006/12/26 19:27:04 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/executor/nodeResult.c,v 1.32.2.2 2007/02/02 00:07:44 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -231,7 +231,7 @@ ExecInitResult(Result *node, EState *estate)
         * initialize tuple type and projection info
         */
        ExecAssignResultTypeFromTL(&resstate->ps);
-       ExecAssignProjectionInfo(&resstate->ps);
+       ExecAssignProjectionInfo(&resstate->ps, NULL);
 
        return resstate;
 }
index 061ca12eda49e016828db6a3317322e44c204cb7..6ee5e13a1dce7ef38fbf41316e9f32ebdfd25f9d 100644 (file)
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/executor/nodeSubplan.c,v 1.70.2.1 2005/11/22 18:23:09 momjian Exp $
+ *       $PostgreSQL: pgsql/src/backend/executor/nodeSubplan.c,v 1.70.2.2 2007/02/02 00:07:44 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -882,14 +882,16 @@ ExecInitSubPlan(SubPlanState *node, EState *estate)
                ExecSetSlotDescriptor(slot, tupDesc, true);
                node->projLeft = ExecBuildProjectionInfo(lefttlist,
                                                                                                 NULL,
-                                                                                                slot);
+                                                                                                slot,
+                                                                                                NULL);
 
                tupDesc = ExecTypeFromTL(rightptlist, false);
                slot = ExecAllocTableSlot(tupTable);
                ExecSetSlotDescriptor(slot, tupDesc, true);
                node->projRight = ExecBuildProjectionInfo(righttlist,
                                                                                                  node->innerecontext,
-                                                                                                 slot);
+                                                                                                 slot,
+                                                                                                 NULL);
        }
 }
 
index 7e14801184d95260a8ae5486b4094b3499a52c1d..8beaf7706f7b4c7b4a0e34cb987da8414fdf1132 100644 (file)
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/executor/executor.h,v 1.120.2.2 2006/01/12 21:49:07 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/executor/executor.h,v 1.120.2.3 2007/02/02 00:07:44 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -222,8 +222,10 @@ extern void ExecAssignResultTypeFromTL(PlanState *planstate);
 extern TupleDesc ExecGetResultType(PlanState *planstate);
 extern ProjectionInfo *ExecBuildProjectionInfo(List *targetList,
                                                ExprContext *econtext,
-                                               TupleTableSlot *slot);
-extern void ExecAssignProjectionInfo(PlanState *planstate);
+                                               TupleTableSlot *slot,
+                                               TupleDesc inputDesc);
+extern void ExecAssignProjectionInfo(PlanState *planstate,
+                                                                        TupleDesc inputDesc);
 extern void ExecFreeExprContext(PlanState *planstate);
 extern TupleDesc ExecGetScanType(ScanState *scanstate);
 extern void ExecAssignScanType(ScanState *scanstate,