/*
* Deparse a BoolExpr node.
- *
- * Note: by the time we get here, AND and OR expressions have been flattened
- * into N-argument form, so we'd better be prepared to deal with that.
*/
static void
deparseBoolExpr(BoolExpr *node, deparse_expr_cxt *context)
/* operator name is deemed uninteresting */
}
break;
+ case T_BoolExpr:
+ {
+ BoolExpr *expr = (BoolExpr *) node;
+
+ if (walker(expr->args, context))
+ return true;
+ }
+ break;
case T_ColumnRef:
/* we assume the fields contain nothing interesting */
break;
appendStringInfoChar(str, ' ');
WRITE_NODE_FIELD(name);
break;
- case AEXPR_AND:
- appendStringInfoString(str, " AND");
- break;
- case AEXPR_OR:
- appendStringInfoString(str, " OR");
- break;
- case AEXPR_NOT:
- appendStringInfoString(str, " NOT");
- break;
case AEXPR_OP_ANY:
appendStringInfoChar(str, ' ');
WRITE_NODE_FIELD(name);
* transformations if any are found.
*
* This routine has to run before preprocess_expression(), so the quals
- * clauses are not yet reduced to implicit-AND format. That means we need
- * to recursively search through explicit AND clauses, which are
- * probably only binary ANDs. We stop as soon as we hit a non-AND item.
+ * clauses are not yet reduced to implicit-AND format, and are not guaranteed
+ * to be AND/OR-flat either. That means we need to recursively search through
+ * explicit AND clauses. We stop as soon as we hit a non-AND item.
*/
void
pull_up_sublinks(PlannerInfo *root)
* Routines for preprocessing qualification expressions
*
*
- * The parser regards AND and OR as purely binary operators, so a qual like
- * (A = 1) OR (A = 2) OR (A = 3) ...
- * will produce a nested parsetree
- * (OR (A = 1) (OR (A = 2) (OR (A = 3) ...)))
- * In reality, the optimizer and executor regard AND and OR as N-argument
- * operators, so this tree can be flattened to
- * (OR (A = 1) (A = 2) (A = 3) ...)
+ * While the parser will produce flattened (N-argument) AND/OR trees from
+ * simple sequences of AND'ed or OR'ed clauses, there might be an AND clause
+ * directly underneath another AND, or OR underneath OR, if the input was
+ * oddly parenthesized. Also, rule expansion and subquery flattening could
+ * produce such parsetrees. The planner wants to flatten all such cases
+ * to ensure consistent optimization behavior.
*
* Formerly, this module was responsible for doing the initial flattening,
* but now we leave it to eval_const_expressions to do that since it has to
List *unprocessed_args;
/*
- * Since the parser considers OR to be a binary operator, long OR lists
- * become deeply nested expressions. We must flatten these into long
- * argument lists of a single OR operator. To avoid blowing out the stack
- * with recursion of eval_const_expressions, we resort to some tenseness
- * here: we keep a list of not-yet-processed inputs, and handle flattening
- * of nested ORs by prepending to the to-do list instead of recursing.
+ * We want to ensure that any OR immediately beneath another OR gets
+ * flattened into a single OR-list, so as to simplify later reasoning.
+ *
+ * To avoid stack overflow from recursion of eval_const_expressions, we
+ * resort to some tenseness here: we keep a list of not-yet-processed
+ * inputs, and handle flattening of nested ORs by prepending to the to-do
+ * list instead of recursing. Now that the parser generates N-argument
+ * ORs from simple lists, this complexity is probably less necessary than
+ * it once was, but we might as well keep the logic.
*/
unprocessed_args = list_copy(args);
while (unprocessed_args)
static Node *makeSetOp(SetOperation op, bool all, Node *larg, Node *rarg);
static Node *doNegate(Node *n, int location);
static void doNegateFloat(Value *v);
+static Node *makeAndExpr(Node *lexpr, Node *rexpr, int location);
+static Node *makeOrExpr(Node *lexpr, Node *rexpr, int location);
+static Node *makeNotExpr(Node *expr, int location);
static Node *makeAArrayExpr(List *elements, int location);
static Node *makeXmlExpr(XmlExprOp op, char *name, List *named_args,
List *args, int location);
{ $$ = (Node *) makeA_Expr(AEXPR_OP, $2, $1, NULL, @2); }
| a_expr AND a_expr
- { $$ = (Node *) makeA_Expr(AEXPR_AND, NIL, $1, $3, @2); }
+ { $$ = makeAndExpr($1, $3, @2); }
| a_expr OR a_expr
- { $$ = (Node *) makeA_Expr(AEXPR_OR, NIL, $1, $3, @2); }
+ { $$ = makeOrExpr($1, $3, @2); }
| NOT a_expr
- { $$ = (Node *) makeA_Expr(AEXPR_NOT, NIL, NULL, $2, @1); }
+ { $$ = makeNotExpr($2, @1); }
| a_expr LIKE a_expr
{ $$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "~~", $1, $3, @2); }
}
| a_expr IS NOT DISTINCT FROM a_expr %prec IS
{
- $$ = (Node *) makeA_Expr(AEXPR_NOT, NIL, NULL,
- (Node *) makeSimpleA_Expr(AEXPR_DISTINCT,
- "=", $1, $6, @2),
- @2);
-
+ $$ = makeNotExpr((Node *) makeSimpleA_Expr(AEXPR_DISTINCT,
+ "=", $1, $6, @2),
+ @2);
}
| a_expr IS OF '(' type_list ')' %prec IS
{
*/
| a_expr BETWEEN opt_asymmetric b_expr AND b_expr %prec BETWEEN
{
- $$ = (Node *) makeA_Expr(AEXPR_AND, NIL,
+ $$ = makeAndExpr(
(Node *) makeSimpleA_Expr(AEXPR_OP, ">=", $1, $4, @2),
(Node *) makeSimpleA_Expr(AEXPR_OP, "<=", $1, $6, @2),
- @2);
+ @2);
}
| a_expr NOT BETWEEN opt_asymmetric b_expr AND b_expr %prec BETWEEN
{
- $$ = (Node *) makeA_Expr(AEXPR_OR, NIL,
+ $$ = makeOrExpr(
(Node *) makeSimpleA_Expr(AEXPR_OP, "<", $1, $5, @2),
(Node *) makeSimpleA_Expr(AEXPR_OP, ">", $1, $7, @2),
- @2);
+ @2);
}
| a_expr BETWEEN SYMMETRIC b_expr AND b_expr %prec BETWEEN
{
- $$ = (Node *) makeA_Expr(AEXPR_OR, NIL,
- (Node *) makeA_Expr(AEXPR_AND, NIL,
+ $$ = makeOrExpr(
+ makeAndExpr(
(Node *) makeSimpleA_Expr(AEXPR_OP, ">=", $1, $4, @2),
(Node *) makeSimpleA_Expr(AEXPR_OP, "<=", $1, $6, @2),
- @2),
- (Node *) makeA_Expr(AEXPR_AND, NIL,
+ @2),
+ makeAndExpr(
(Node *) makeSimpleA_Expr(AEXPR_OP, ">=", $1, $6, @2),
(Node *) makeSimpleA_Expr(AEXPR_OP, "<=", $1, $4, @2),
- @2),
- @2);
+ @2),
+ @2);
}
| a_expr NOT BETWEEN SYMMETRIC b_expr AND b_expr %prec BETWEEN
{
- $$ = (Node *) makeA_Expr(AEXPR_AND, NIL,
- (Node *) makeA_Expr(AEXPR_OR, NIL,
+ $$ = makeAndExpr(
+ makeOrExpr(
(Node *) makeSimpleA_Expr(AEXPR_OP, "<", $1, $5, @2),
(Node *) makeSimpleA_Expr(AEXPR_OP, ">", $1, $7, @2),
- @2),
- (Node *) makeA_Expr(AEXPR_OR, NIL,
+ @2),
+ makeOrExpr(
(Node *) makeSimpleA_Expr(AEXPR_OP, "<", $1, $7, @2),
(Node *) makeSimpleA_Expr(AEXPR_OP, ">", $1, $5, @2),
- @2),
- @2);
+ @2),
+ @2);
}
| a_expr IN_P in_expr
{
n->operName = list_make1(makeString("="));
n->location = @3;
/* Stick a NOT on top */
- $$ = (Node *) makeA_Expr(AEXPR_NOT, NIL, NULL, (Node *) n, @2);
+ $$ = makeNotExpr((Node *) n, @2);
}
else
{
}
| a_expr IS NOT DOCUMENT_P %prec IS
{
- $$ = (Node *) makeA_Expr(AEXPR_NOT, NIL, NULL,
- makeXmlExpr(IS_DOCUMENT, NULL, NIL,
- list_make1($1), @2),
- @2);
+ $$ = makeNotExpr(makeXmlExpr(IS_DOCUMENT, NULL, NIL,
+ list_make1($1), @2),
+ @2);
}
;
}
| b_expr IS NOT DISTINCT FROM b_expr %prec IS
{
- $$ = (Node *) makeA_Expr(AEXPR_NOT, NIL,
- NULL, (Node *) makeSimpleA_Expr(AEXPR_DISTINCT, "=", $1, $6, @2), @2);
+ $$ = makeNotExpr((Node *) makeSimpleA_Expr(AEXPR_DISTINCT,
+ "=", $1, $6, @2),
+ @2);
}
| b_expr IS OF '(' type_list ')' %prec IS
{
}
| b_expr IS NOT DOCUMENT_P %prec IS
{
- $$ = (Node *) makeA_Expr(AEXPR_NOT, NIL, NULL,
- makeXmlExpr(IS_DOCUMENT, NULL, NIL,
- list_make1($1), @2),
- @2);
+ $$ = makeNotExpr(makeXmlExpr(IS_DOCUMENT, NULL, NIL,
+ list_make1($1), @2),
+ @2);
}
;
v->val.str = psprintf("-%s", oldval);
}
+static Node *
+makeAndExpr(Node *lexpr, Node *rexpr, int location)
+{
+ /* Flatten "a AND b AND c ..." to a single BoolExpr on sight */
+ if (IsA(lexpr, BoolExpr))
+ {
+ BoolExpr *blexpr = (BoolExpr *) lexpr;
+
+ if (blexpr->boolop == AND_EXPR)
+ {
+ blexpr->args = lappend(blexpr->args, rexpr);
+ return (Node *) blexpr;
+ }
+ }
+ return (Node *) makeBoolExpr(AND_EXPR, list_make2(lexpr, rexpr), location);
+}
+
+static Node *
+makeOrExpr(Node *lexpr, Node *rexpr, int location)
+{
+ /* Flatten "a OR b OR c ..." to a single BoolExpr on sight */
+ if (IsA(lexpr, BoolExpr))
+ {
+ BoolExpr *blexpr = (BoolExpr *) lexpr;
+
+ if (blexpr->boolop == OR_EXPR)
+ {
+ blexpr->args = lappend(blexpr->args, rexpr);
+ return (Node *) blexpr;
+ }
+ }
+ return (Node *) makeBoolExpr(OR_EXPR, list_make2(lexpr, rexpr), location);
+}
+
+static Node *
+makeNotExpr(Node *expr, int location)
+{
+ return (Node *) makeBoolExpr(NOT_EXPR, list_make1(expr), location);
+}
+
static Node *
makeAArrayExpr(List *elements, int location)
{
RangeTblEntry *leftRTE, RangeTblEntry *rightRTE,
List *leftVars, List *rightVars)
{
- Node *result = NULL;
+ Node *result;
+ List *andargs = NIL;
ListCell *lvars,
*rvars;
copyObject(lvar), copyObject(rvar),
-1);
- /* And combine into an AND clause, if multiple join columns */
- if (result == NULL)
- result = (Node *) e;
- else
- {
- A_Expr *a;
-
- a = makeA_Expr(AEXPR_AND, NIL, result, (Node *) e, -1);
- result = (Node *) a;
- }
+ /* Prepare to combine into an AND clause, if multiple join columns */
+ andargs = lappend(andargs, e);
}
+ /* Only need an AND if there's more than one join column */
+ if (list_length(andargs) == 1)
+ result = (Node *) linitial(andargs);
+ else
+ result = (Node *) makeBoolExpr(AND_EXPR, andargs, -1);
+
/*
* Since the references are already Vars, and are certainly from the input
* relations, we don't have to go through the same pushups that
static Node *transformExprRecurse(ParseState *pstate, Node *expr);
static Node *transformParamRef(ParseState *pstate, ParamRef *pref);
static Node *transformAExprOp(ParseState *pstate, A_Expr *a);
-static Node *transformAExprAnd(ParseState *pstate, A_Expr *a);
-static Node *transformAExprOr(ParseState *pstate, A_Expr *a);
-static Node *transformAExprNot(ParseState *pstate, A_Expr *a);
static Node *transformAExprOpAny(ParseState *pstate, A_Expr *a);
static Node *transformAExprOpAll(ParseState *pstate, A_Expr *a);
static Node *transformAExprDistinct(ParseState *pstate, A_Expr *a);
static Node *transformAExprNullIf(ParseState *pstate, A_Expr *a);
static Node *transformAExprOf(ParseState *pstate, A_Expr *a);
static Node *transformAExprIn(ParseState *pstate, A_Expr *a);
+static Node *transformBoolExpr(ParseState *pstate, BoolExpr *a);
static Node *transformFuncCall(ParseState *pstate, FuncCall *fn);
static Node *transformCaseExpr(ParseState *pstate, CaseExpr *c);
static Node *transformSubLink(ParseState *pstate, SubLink *sublink);
case AEXPR_OP:
result = transformAExprOp(pstate, a);
break;
- case AEXPR_AND:
- result = transformAExprAnd(pstate, a);
- break;
- case AEXPR_OR:
- result = transformAExprOr(pstate, a);
- break;
- case AEXPR_NOT:
- result = transformAExprNot(pstate, a);
- break;
case AEXPR_OP_ANY:
result = transformAExprOpAny(pstate, a);
break;
break;
}
+ case T_BoolExpr:
+ result = transformBoolExpr(pstate, (BoolExpr *) expr);
+ break;
+
case T_FuncCall:
result = transformFuncCall(pstate, (FuncCall *) expr);
break;
case T_DistinctExpr:
case T_NullIfExpr:
case T_ScalarArrayOpExpr:
- case T_BoolExpr:
case T_FieldSelect:
case T_FieldStore:
case T_RelabelType:
return result;
}
-static Node *
-transformAExprAnd(ParseState *pstate, A_Expr *a)
-{
- Node *lexpr = transformExprRecurse(pstate, a->lexpr);
- Node *rexpr = transformExprRecurse(pstate, a->rexpr);
-
- lexpr = coerce_to_boolean(pstate, lexpr, "AND");
- rexpr = coerce_to_boolean(pstate, rexpr, "AND");
-
- return (Node *) makeBoolExpr(AND_EXPR,
- list_make2(lexpr, rexpr),
- a->location);
-}
-
-static Node *
-transformAExprOr(ParseState *pstate, A_Expr *a)
-{
- Node *lexpr = transformExprRecurse(pstate, a->lexpr);
- Node *rexpr = transformExprRecurse(pstate, a->rexpr);
-
- lexpr = coerce_to_boolean(pstate, lexpr, "OR");
- rexpr = coerce_to_boolean(pstate, rexpr, "OR");
-
- return (Node *) makeBoolExpr(OR_EXPR,
- list_make2(lexpr, rexpr),
- a->location);
-}
-
-static Node *
-transformAExprNot(ParseState *pstate, A_Expr *a)
-{
- Node *rexpr = transformExprRecurse(pstate, a->rexpr);
-
- rexpr = coerce_to_boolean(pstate, rexpr, "NOT");
-
- return (Node *) makeBoolExpr(NOT_EXPR,
- list_make1(rexpr),
- a->location);
-}
-
static Node *
transformAExprOpAny(ParseState *pstate, A_Expr *a)
{
return result;
}
+static Node *
+transformBoolExpr(ParseState *pstate, BoolExpr *a)
+{
+ List *args = NIL;
+ const char *opname;
+ ListCell *lc;
+
+ switch (a->boolop)
+ {
+ case AND_EXPR:
+ opname = "AND";
+ break;
+ case OR_EXPR:
+ opname = "OR";
+ break;
+ case NOT_EXPR:
+ opname = "NOT";
+ break;
+ default:
+ elog(ERROR, "unrecognized boolop: %d", (int) a->boolop);
+ opname = NULL; /* keep compiler quiet */
+ break;
+ }
+
+ foreach(lc, a->args)
+ {
+ Node *arg = (Node *) lfirst(lc);
+
+ arg = transformExprRecurse(pstate, arg);
+ arg = coerce_to_boolean(pstate, arg, opname);
+ args = lappend(args, arg);
+ }
+
+ return (Node *) makeBoolExpr(a->boolop, args, a->location);
+}
+
static Node *
transformFuncCall(ParseState *pstate, FuncCall *fn)
{
/*
* For = and <> cases, we just combine the pairwise operators with AND or
* OR respectively.
- *
- * Note: this is presently the only place where the parser generates
- * BoolExpr with more than two arguments. Should be OK since the rest of
- * the system thinks BoolExpr is N-argument anyway.
*/
if (rctype == ROWCOMPARE_EQ)
return (Node *) makeBoolExpr(AND_EXPR, opexprs, location);
typedef enum A_Expr_Kind
{
AEXPR_OP, /* normal operator */
- AEXPR_AND, /* booleans - name field is unused */
- AEXPR_OR,
- AEXPR_NOT,
AEXPR_OP_ANY, /* scalar op ANY (array) */
AEXPR_OP_ALL, /* scalar op ALL (array) */
AEXPR_DISTINCT, /* IS DISTINCT FROM - name must be "=" */
* BoolExpr - expression node for the basic Boolean operators AND, OR, NOT
*
* Notice the arguments are given as a List. For NOT, of course the list
- * must always have exactly one element. For AND and OR, the executor can
- * handle any number of arguments. The parser generally treats AND and OR
- * as binary and so it typically only produces two-element lists, but the
- * optimizer will flatten trees of AND and OR nodes to produce longer lists
- * when possible. There are also a few special cases where more arguments
- * can appear before optimization.
+ * must always have exactly one element. For AND and OR, there can be two
+ * or more arguments.
*/
typedef enum BoolExprType
{
int4smaller(rsh.sh_avail, rsl.sl_avail) AS total_avail
FROM shoe rsh,
shoelace rsl
- WHERE (((rsl.sl_color = rsh.slcolor) AND (rsl.sl_len_cm >= rsh.slminlen_cm)) AND (rsl.sl_len_cm <= rsh.slmaxlen_cm));
+ WHERE ((rsl.sl_color = rsh.slcolor) AND (rsl.sl_len_cm >= rsh.slminlen_cm) AND (rsl.sl_len_cm <= rsh.slmaxlen_cm));
shoelace| SELECT s.sl_name,
s.sl_avail,
s.sl_color,
projects / postgresql / commitdiff