mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-12-27 08:39:28 +08:00
Teach predtest.c how to reason about ScalarArrayOpExpr clauses as though
they were broken-out AND or OR lists. The least grotty way to do this seemed to be to set up a general mechanism for handling nodes as though they were ANDs or ORs. There's no other immediate use for it, but perhaps we might want to use the mechanism someday for things like BETWEEN SYMMETRIC.
This commit is contained in:
Tom Lane
parent
1b68a88f22
commit
8a9acd3c41
@ -9,7 +9,7 @@
|
||||
*
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $PostgreSQL: pgsql/src/backend/optimizer/util/predtest.c,v 1.4 2005/10/15 02:49:21 momjian Exp $
|
||||
* $PostgreSQL: pgsql/src/backend/optimizer/util/predtest.c,v 1.5 2005/11/27 22:15:42 tgl Exp $
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
@ -21,13 +21,65 @@
|
||||
#include "executor/executor.h"
|
||||
#include "optimizer/clauses.h"
|
||||
#include "optimizer/predtest.h"
|
||||
#include "utils/array.h"
|
||||
#include "utils/catcache.h"
|
||||
#include "utils/lsyscache.h"
|
||||
#include "utils/syscache.h"
|
||||
|
||||
|
||||
/*
|
||||
* To avoid redundant coding in predicate_implied_by_recurse and
|
||||
* predicate_refuted_by_recurse, we need to abstract out the notion of
|
||||
* iterating over the components of an expression that is logically an AND
|
||||
* or OR structure. There are multiple sorts of expression nodes that can
|
||||
* be treated as ANDs or ORs, and we don't want to code each one separately.
|
||||
* Hence, these types and support routines.
|
||||
*/
|
||||
typedef enum
|
||||
{
|
||||
CLASS_ATOM, /* expression that's not AND or OR */
|
||||
CLASS_AND, /* expression with AND semantics */
|
||||
CLASS_OR /* expression with OR semantics */
|
||||
} PredClass;
|
||||
|
||||
typedef struct PredIterInfoData *PredIterInfo;
|
||||
|
||||
typedef struct PredIterInfoData
|
||||
{
|
||||
/* node-type-specific iteration state */
|
||||
void *state;
|
||||
/* initialize to do the iteration */
|
||||
void (*startup_fn) (Node *clause, PredIterInfo info);
|
||||
/* next-component iteration function */
|
||||
Node *(*next_fn) (PredIterInfo info);
|
||||
/* release resources when done with iteration */
|
||||
void (*cleanup_fn) (PredIterInfo info);
|
||||
} PredIterInfoData;
|
||||
|
||||
#define iterate_begin(item, clause, info) \
|
||||
do { \
|
||||
Node *item; \
|
||||
(info).startup_fn((clause), &(info)); \
|
||||
while ((item = (info).next_fn(&(info))) != NULL)
|
||||
|
||||
#define iterate_end(info) \
|
||||
(info).cleanup_fn(&(info)); \
|
||||
} while (0)
|
||||
|
||||
|
||||
static bool predicate_implied_by_recurse(Node *clause, Node *predicate);
|
||||
static bool predicate_refuted_by_recurse(Node *clause, Node *predicate);
|
||||
static PredClass predicate_classify(Node *clause, PredIterInfo info);
|
||||
static void list_startup_fn(Node *clause, PredIterInfo info);
|
||||
static Node *list_next_fn(PredIterInfo info);
|
||||
static void list_cleanup_fn(PredIterInfo info);
|
||||
static void boolexpr_startup_fn(Node *clause, PredIterInfo info);
|
||||
static void arrayconst_startup_fn(Node *clause, PredIterInfo info);
|
||||
static Node *arrayconst_next_fn(PredIterInfo info);
|
||||
static void arrayconst_cleanup_fn(PredIterInfo info);
|
||||
static void arrayexpr_startup_fn(Node *clause, PredIterInfo info);
|
||||
static Node *arrayexpr_next_fn(PredIterInfo info);
|
||||
static void arrayexpr_cleanup_fn(PredIterInfo info);
|
||||
static bool predicate_implied_by_simple_clause(Expr *predicate, Node *clause);
|
||||
static bool predicate_refuted_by_simple_clause(Expr *predicate, Node *clause);
|
||||
static bool btree_predicate_proof(Expr *predicate, Node *clause,
|
||||
@ -56,29 +108,14 @@ static bool btree_predicate_proof(Expr *predicate, Node *clause,
|
||||
bool
|
||||
predicate_implied_by(List *predicate_list, List *restrictinfo_list)
|
||||
{
|
||||
ListCell *item;
|
||||
|
||||
if (predicate_list == NIL)
|
||||
return true; /* no predicate: implication is vacuous */
|
||||
if (restrictinfo_list == NIL)
|
||||
return false; /* no restriction: implication must fail */
|
||||
|
||||
/*
|
||||
* In all cases where the predicate is an AND-clause,
|
||||
* predicate_implied_by_recurse() will prefer to iterate over the
|
||||
* predicate's components. So we can just do that to start with here, and
|
||||
* eliminate the need for predicate_implied_by_recurse() to handle a bare
|
||||
* List on the predicate side.
|
||||
*
|
||||
* Logic is: restriction must imply each of the AND'ed predicate items.
|
||||
*/
|
||||
foreach(item, predicate_list)
|
||||
{
|
||||
if (!predicate_implied_by_recurse((Node *) restrictinfo_list,
|
||||
lfirst(item)))
|
||||
return false;
|
||||
}
|
||||
return true;
|
||||
/* Otherwise, away we go ... */
|
||||
return predicate_implied_by_recurse((Node *) restrictinfo_list,
|
||||
(Node *) predicate_list);
|
||||
}
|
||||
|
||||
/*
|
||||
@ -109,13 +146,7 @@ predicate_refuted_by(List *predicate_list, List *restrictinfo_list)
|
||||
if (restrictinfo_list == NIL)
|
||||
return false; /* no restriction: refutation must fail */
|
||||
|
||||
/*
|
||||
* Unlike the implication case, predicate_refuted_by_recurse needs to be
|
||||
* able to see the top-level AND structure on both sides --- otherwise it
|
||||
* will fail to handle the case where one restriction clause is an OR that
|
||||
* can refute the predicate AND as a whole, but not each predicate clause
|
||||
* separately.
|
||||
*/
|
||||
/* Otherwise, away we go ... */
|
||||
return predicate_refuted_by_recurse((Node *) restrictinfo_list,
|
||||
(Node *) predicate_list);
|
||||
}
|
||||
@ -151,11 +182,6 @@ predicate_refuted_by(List *predicate_list, List *restrictinfo_list)
|
||||
* This is still not an exhaustive test, but it handles most normal cases
|
||||
* under the assumption that both inputs have been AND/OR flattened.
|
||||
*
|
||||
* A bare List node on the restriction side is interpreted as an AND clause,
|
||||
* in order to handle the top-level restriction List properly. However we
|
||||
* need not consider a List on the predicate side since predicate_implied_by()
|
||||
* already expanded it.
|
||||
*
|
||||
* We have to be prepared to handle RestrictInfo nodes in the restrictinfo
|
||||
* tree, though not in the predicate tree.
|
||||
*----------
|
||||
@ -163,130 +189,192 @@ predicate_refuted_by(List *predicate_list, List *restrictinfo_list)
|
||||
static bool
|
||||
predicate_implied_by_recurse(Node *clause, Node *predicate)
|
||||
{
|
||||
ListCell *item;
|
||||
PredIterInfoData clause_info;
|
||||
PredIterInfoData pred_info;
|
||||
PredClass pclass;
|
||||
bool result;
|
||||
|
||||
Assert(clause != NULL);
|
||||
/* skip through RestrictInfo */
|
||||
if (IsA(clause, RestrictInfo))
|
||||
{
|
||||
clause = (Node *) ((RestrictInfo *) clause)->clause;
|
||||
Assert(clause != NULL);
|
||||
Assert(!IsA(clause, RestrictInfo));
|
||||
}
|
||||
Assert(predicate != NULL);
|
||||
if (IsA(clause, RestrictInfo))
|
||||
clause = (Node *) ((RestrictInfo *) clause)->clause;
|
||||
|
||||
pclass = predicate_classify(predicate, &pred_info);
|
||||
|
||||
switch (predicate_classify(clause, &clause_info))
|
||||
{
|
||||
case CLASS_AND:
|
||||
switch (pclass)
|
||||
{
|
||||
case CLASS_AND:
|
||||
/*
|
||||
* Since a restriction List clause is handled the same as an AND clause,
|
||||
* we can avoid duplicate code like this:
|
||||
* AND-clause => AND-clause if A implies each of B's items
|
||||
*/
|
||||
if (and_clause(clause))
|
||||
clause = (Node *) ((BoolExpr *) clause)->args;
|
||||
|
||||
if (IsA(clause, List))
|
||||
result = true;
|
||||
iterate_begin(pitem, predicate, pred_info)
|
||||
{
|
||||
if (and_clause(predicate))
|
||||
if (!predicate_implied_by_recurse(clause, pitem))
|
||||
{
|
||||
/* AND-clause => AND-clause if A implies each of B's items */
|
||||
foreach(item, ((BoolExpr *) predicate)->args)
|
||||
{
|
||||
if (!predicate_implied_by_recurse(clause, lfirst(item)))
|
||||
return false;
|
||||
}
|
||||
return true;
|
||||
}
|
||||
else if (or_clause(predicate))
|
||||
{
|
||||
/* AND-clause => OR-clause if A implies any of B's items */
|
||||
/* Needed to handle (x AND y) => ((x AND y) OR z) */
|
||||
foreach(item, ((BoolExpr *) predicate)->args)
|
||||
{
|
||||
if (predicate_implied_by_recurse(clause, lfirst(item)))
|
||||
return true;
|
||||
}
|
||||
/* Also check if any of A's items implies B */
|
||||
/* Needed to handle ((x OR y) AND z) => (x OR y) */
|
||||
foreach(item, (List *) clause)
|
||||
{
|
||||
if (predicate_implied_by_recurse(lfirst(item), predicate))
|
||||
return true;
|
||||
}
|
||||
return false;
|
||||
}
|
||||
else
|
||||
{
|
||||
/* AND-clause => atom if any of A's items implies B */
|
||||
foreach(item, (List *) clause)
|
||||
{
|
||||
if (predicate_implied_by_recurse(lfirst(item), predicate))
|
||||
return true;
|
||||
}
|
||||
return false;
|
||||
}
|
||||
}
|
||||
else if (or_clause(clause))
|
||||
{
|
||||
if (or_clause(predicate))
|
||||
{
|
||||
/*
|
||||
* OR-clause => OR-clause if each of A's items implies any of B's
|
||||
* items. Messy but can't do it any more simply.
|
||||
*/
|
||||
foreach(item, ((BoolExpr *) clause)->args)
|
||||
{
|
||||
Node *citem = lfirst(item);
|
||||
ListCell *item2;
|
||||
|
||||
foreach(item2, ((BoolExpr *) predicate)->args)
|
||||
{
|
||||
if (predicate_implied_by_recurse(citem, lfirst(item2)))
|
||||
result = false;
|
||||
break;
|
||||
}
|
||||
if (item2 == NULL)
|
||||
return false; /* doesn't imply any of B's */
|
||||
}
|
||||
return true;
|
||||
}
|
||||
else
|
||||
iterate_end(pred_info);
|
||||
return result;
|
||||
|
||||
case CLASS_OR:
|
||||
/*
|
||||
* AND-clause => OR-clause if A implies any of B's items
|
||||
*
|
||||
* Needed to handle (x AND y) => ((x AND y) OR z)
|
||||
*/
|
||||
result = false;
|
||||
iterate_begin(pitem, predicate, pred_info)
|
||||
{
|
||||
/* OR-clause => AND-clause if each of A's items implies B */
|
||||
/* OR-clause => atom if each of A's items implies B */
|
||||
foreach(item, ((BoolExpr *) clause)->args)
|
||||
if (predicate_implied_by_recurse(clause, pitem))
|
||||
{
|
||||
if (!predicate_implied_by_recurse(lfirst(item), predicate))
|
||||
return false;
|
||||
}
|
||||
return true;
|
||||
result = true;
|
||||
break;
|
||||
}
|
||||
}
|
||||
else
|
||||
iterate_end(pred_info);
|
||||
if (result)
|
||||
return result;
|
||||
/*
|
||||
* Also check if any of A's items implies B
|
||||
*
|
||||
* Needed to handle ((x OR y) AND z) => (x OR y)
|
||||
*/
|
||||
iterate_begin(citem, clause, clause_info)
|
||||
{
|
||||
if (and_clause(predicate))
|
||||
if (predicate_implied_by_recurse(citem, predicate))
|
||||
{
|
||||
/* atom => AND-clause if A implies each of B's items */
|
||||
foreach(item, ((BoolExpr *) predicate)->args)
|
||||
{
|
||||
if (!predicate_implied_by_recurse(clause, lfirst(item)))
|
||||
return false;
|
||||
result = true;
|
||||
break;
|
||||
}
|
||||
return true;
|
||||
}
|
||||
else if (or_clause(predicate))
|
||||
iterate_end(clause_info);
|
||||
return result;
|
||||
|
||||
case CLASS_ATOM:
|
||||
/*
|
||||
* AND-clause => atom if any of A's items implies B
|
||||
*/
|
||||
result = false;
|
||||
iterate_begin(citem, clause, clause_info)
|
||||
{
|
||||
/* atom => OR-clause if A implies any of B's items */
|
||||
foreach(item, ((BoolExpr *) predicate)->args)
|
||||
if (predicate_implied_by_recurse(citem, predicate))
|
||||
{
|
||||
if (predicate_implied_by_recurse(clause, lfirst(item)))
|
||||
return true;
|
||||
result = true;
|
||||
break;
|
||||
}
|
||||
return false;
|
||||
}
|
||||
else
|
||||
iterate_end(clause_info);
|
||||
return result;
|
||||
}
|
||||
break;
|
||||
|
||||
case CLASS_OR:
|
||||
switch (pclass)
|
||||
{
|
||||
/* atom => atom is the base case */
|
||||
return predicate_implied_by_simple_clause((Expr *) predicate,
|
||||
case CLASS_OR:
|
||||
/*
|
||||
* OR-clause => OR-clause if each of A's items implies any
|
||||
* of B's items. Messy but can't do it any more simply.
|
||||
*/
|
||||
result = true;
|
||||
iterate_begin(citem, clause, clause_info)
|
||||
{
|
||||
bool presult = false;
|
||||
|
||||
iterate_begin(pitem, predicate, pred_info)
|
||||
{
|
||||
if (predicate_implied_by_recurse(citem, pitem))
|
||||
{
|
||||
presult = true;
|
||||
break;
|
||||
}
|
||||
}
|
||||
iterate_end(pred_info);
|
||||
if (!presult)
|
||||
{
|
||||
result = false; /* doesn't imply any of B's */
|
||||
break;
|
||||
}
|
||||
}
|
||||
iterate_end(clause_info);
|
||||
return result;
|
||||
|
||||
case CLASS_AND:
|
||||
case CLASS_ATOM:
|
||||
/*
|
||||
* OR-clause => AND-clause if each of A's items implies B
|
||||
*
|
||||
* OR-clause => atom if each of A's items implies B
|
||||
*/
|
||||
result = true;
|
||||
iterate_begin(citem, clause, clause_info)
|
||||
{
|
||||
if (!predicate_implied_by_recurse(citem, predicate))
|
||||
{
|
||||
result = false;
|
||||
break;
|
||||
}
|
||||
}
|
||||
iterate_end(clause_info);
|
||||
return result;
|
||||
}
|
||||
break;
|
||||
|
||||
case CLASS_ATOM:
|
||||
switch (pclass)
|
||||
{
|
||||
case CLASS_AND:
|
||||
/*
|
||||
* atom => AND-clause if A implies each of B's items
|
||||
*/
|
||||
result = true;
|
||||
iterate_begin(pitem, predicate, pred_info)
|
||||
{
|
||||
if (!predicate_implied_by_recurse(clause, pitem))
|
||||
{
|
||||
result = false;
|
||||
break;
|
||||
}
|
||||
}
|
||||
iterate_end(pred_info);
|
||||
return result;
|
||||
|
||||
case CLASS_OR:
|
||||
/*
|
||||
* atom => OR-clause if A implies any of B's items
|
||||
*/
|
||||
result = false;
|
||||
iterate_begin(pitem, predicate, pred_info)
|
||||
{
|
||||
if (predicate_implied_by_recurse(clause, pitem))
|
||||
{
|
||||
result = true;
|
||||
break;
|
||||
}
|
||||
}
|
||||
iterate_end(pred_info);
|
||||
return result;
|
||||
|
||||
case CLASS_ATOM:
|
||||
/*
|
||||
* atom => atom is the base case
|
||||
*/
|
||||
return
|
||||
predicate_implied_by_simple_clause((Expr *) predicate,
|
||||
clause);
|
||||
}
|
||||
break;
|
||||
}
|
||||
|
||||
/* can't get here */
|
||||
elog(ERROR, "predicate_classify returned a bogus value");
|
||||
return false;
|
||||
}
|
||||
|
||||
/*----------
|
||||
@ -306,150 +394,465 @@ predicate_implied_by_recurse(Node *clause, Node *predicate)
|
||||
* OR-expr A R=> AND-expr B iff: each of A's components R=> any of B's
|
||||
* OR-expr A R=> OR-expr B iff: A R=> each of B's components
|
||||
*
|
||||
* Other comments are as for predicate_implied_by_recurse(), except that
|
||||
* we have to handle a top-level AND list on both sides.
|
||||
* Other comments are as for predicate_implied_by_recurse().
|
||||
*----------
|
||||
*/
|
||||
static bool
|
||||
predicate_refuted_by_recurse(Node *clause, Node *predicate)
|
||||
{
|
||||
ListCell *item;
|
||||
PredIterInfoData clause_info;
|
||||
PredIterInfoData pred_info;
|
||||
PredClass pclass;
|
||||
bool result;
|
||||
|
||||
Assert(clause != NULL);
|
||||
/* skip through RestrictInfo */
|
||||
if (IsA(clause, RestrictInfo))
|
||||
{
|
||||
clause = (Node *) ((RestrictInfo *) clause)->clause;
|
||||
Assert(clause != NULL);
|
||||
Assert(!IsA(clause, RestrictInfo));
|
||||
}
|
||||
Assert(predicate != NULL);
|
||||
if (IsA(clause, RestrictInfo))
|
||||
clause = (Node *) ((RestrictInfo *) clause)->clause;
|
||||
|
||||
pclass = predicate_classify(predicate, &pred_info);
|
||||
|
||||
switch (predicate_classify(clause, &clause_info))
|
||||
{
|
||||
case CLASS_AND:
|
||||
switch (pclass)
|
||||
{
|
||||
case CLASS_AND:
|
||||
/*
|
||||
* Since a restriction List clause is handled the same as an AND clause,
|
||||
* we can avoid duplicate code like this:
|
||||
* AND-clause R=> AND-clause if A refutes any of B's items
|
||||
*
|
||||
* Needed to handle (x AND y) R=> ((!x OR !y) AND z)
|
||||
*/
|
||||
if (and_clause(clause))
|
||||
clause = (Node *) ((BoolExpr *) clause)->args;
|
||||
|
||||
/* Ditto for predicate AND-clause and List */
|
||||
if (and_clause(predicate))
|
||||
predicate = (Node *) ((BoolExpr *) predicate)->args;
|
||||
|
||||
if (IsA(clause, List))
|
||||
result = false;
|
||||
iterate_begin(pitem, predicate, pred_info)
|
||||
{
|
||||
if (IsA(predicate, List))
|
||||
if (predicate_refuted_by_recurse(clause, pitem))
|
||||
{
|
||||
/* AND-clause R=> AND-clause if A refutes any of B's items */
|
||||
/* Needed to handle (x AND y) R=> ((!x OR !y) AND z) */
|
||||
foreach(item, (List *) predicate)
|
||||
{
|
||||
if (predicate_refuted_by_recurse(clause, lfirst(item)))
|
||||
return true;
|
||||
}
|
||||
/* Also check if any of A's items refutes B */
|
||||
/* Needed to handle ((x OR y) AND z) R=> (!x AND !y) */
|
||||
foreach(item, (List *) clause)
|
||||
{
|
||||
if (predicate_refuted_by_recurse(lfirst(item), predicate))
|
||||
return true;
|
||||
}
|
||||
return false;
|
||||
}
|
||||
else if (or_clause(predicate))
|
||||
{
|
||||
/* AND-clause R=> OR-clause if A refutes each of B's items */
|
||||
foreach(item, ((BoolExpr *) predicate)->args)
|
||||
{
|
||||
if (!predicate_refuted_by_recurse(clause, lfirst(item)))
|
||||
return false;
|
||||
}
|
||||
return true;
|
||||
}
|
||||
else
|
||||
{
|
||||
/* AND-clause R=> atom if any of A's items refutes B */
|
||||
foreach(item, (List *) clause)
|
||||
{
|
||||
if (predicate_refuted_by_recurse(lfirst(item), predicate))
|
||||
return true;
|
||||
}
|
||||
return false;
|
||||
}
|
||||
}
|
||||
else if (or_clause(clause))
|
||||
{
|
||||
if (or_clause(predicate))
|
||||
{
|
||||
/* OR-clause R=> OR-clause if A refutes each of B's items */
|
||||
foreach(item, ((BoolExpr *) predicate)->args)
|
||||
{
|
||||
if (!predicate_refuted_by_recurse(clause, lfirst(item)))
|
||||
return false;
|
||||
}
|
||||
return true;
|
||||
}
|
||||
else if (IsA(predicate, List))
|
||||
{
|
||||
/*
|
||||
* OR-clause R=> AND-clause if each of A's items refutes any of
|
||||
* B's items.
|
||||
*/
|
||||
foreach(item, ((BoolExpr *) clause)->args)
|
||||
{
|
||||
Node *citem = lfirst(item);
|
||||
ListCell *item2;
|
||||
|
||||
foreach(item2, (List *) predicate)
|
||||
{
|
||||
if (predicate_refuted_by_recurse(citem, lfirst(item2)))
|
||||
result = true;
|
||||
break;
|
||||
}
|
||||
if (item2 == NULL)
|
||||
return false; /* citem refutes nothing */
|
||||
}
|
||||
return true;
|
||||
}
|
||||
else
|
||||
iterate_end(pred_info);
|
||||
if (result)
|
||||
return result;
|
||||
/*
|
||||
* Also check if any of A's items refutes B
|
||||
*
|
||||
* Needed to handle ((x OR y) AND z) R=> (!x AND !y)
|
||||
*/
|
||||
iterate_begin(citem, clause, clause_info)
|
||||
{
|
||||
/* OR-clause R=> atom if each of A's items refutes B */
|
||||
foreach(item, ((BoolExpr *) clause)->args)
|
||||
if (predicate_refuted_by_recurse(citem, predicate))
|
||||
{
|
||||
if (!predicate_refuted_by_recurse(lfirst(item), predicate))
|
||||
return false;
|
||||
}
|
||||
return true;
|
||||
result = true;
|
||||
break;
|
||||
}
|
||||
}
|
||||
else
|
||||
iterate_end(clause_info);
|
||||
return result;
|
||||
|
||||
case CLASS_OR:
|
||||
/*
|
||||
* AND-clause R=> OR-clause if A refutes each of B's items
|
||||
*/
|
||||
result = true;
|
||||
iterate_begin(pitem, predicate, pred_info)
|
||||
{
|
||||
if (IsA(predicate, List))
|
||||
if (!predicate_refuted_by_recurse(clause, pitem))
|
||||
{
|
||||
/* atom R=> AND-clause if A refutes any of B's items */
|
||||
foreach(item, (List *) predicate)
|
||||
{
|
||||
if (predicate_refuted_by_recurse(clause, lfirst(item)))
|
||||
return true;
|
||||
result = false;
|
||||
break;
|
||||
}
|
||||
return false;
|
||||
}
|
||||
else if (or_clause(predicate))
|
||||
iterate_end(pred_info);
|
||||
return result;
|
||||
|
||||
case CLASS_ATOM:
|
||||
/*
|
||||
* AND-clause R=> atom if any of A's items refutes B
|
||||
*/
|
||||
result = false;
|
||||
iterate_begin(citem, clause, clause_info)
|
||||
{
|
||||
/* atom R=> OR-clause if A refutes each of B's items */
|
||||
foreach(item, ((BoolExpr *) predicate)->args)
|
||||
if (predicate_refuted_by_recurse(citem, predicate))
|
||||
{
|
||||
if (!predicate_refuted_by_recurse(clause, lfirst(item)))
|
||||
return false;
|
||||
result = true;
|
||||
break;
|
||||
}
|
||||
return true;
|
||||
}
|
||||
else
|
||||
iterate_end(clause_info);
|
||||
return result;
|
||||
}
|
||||
break;
|
||||
|
||||
case CLASS_OR:
|
||||
switch (pclass)
|
||||
{
|
||||
/* atom R=> atom is the base case */
|
||||
return predicate_refuted_by_simple_clause((Expr *) predicate,
|
||||
case CLASS_OR:
|
||||
/*
|
||||
* OR-clause R=> OR-clause if A refutes each of B's items
|
||||
*/
|
||||
result = true;
|
||||
iterate_begin(pitem, predicate, pred_info)
|
||||
{
|
||||
if (!predicate_refuted_by_recurse(clause, pitem))
|
||||
{
|
||||
result = false;
|
||||
break;
|
||||
}
|
||||
}
|
||||
iterate_end(pred_info);
|
||||
return result;
|
||||
|
||||
case CLASS_AND:
|
||||
/*
|
||||
* OR-clause R=> AND-clause if each of A's items refutes
|
||||
* any of B's items.
|
||||
*/
|
||||
result = true;
|
||||
iterate_begin(citem, clause, clause_info)
|
||||
{
|
||||
bool presult = false;
|
||||
|
||||
iterate_begin(pitem, predicate, pred_info)
|
||||
{
|
||||
if (predicate_refuted_by_recurse(citem, pitem))
|
||||
{
|
||||
presult = true;
|
||||
break;
|
||||
}
|
||||
}
|
||||
iterate_end(pred_info);
|
||||
if (!presult)
|
||||
{
|
||||
result = false; /* citem refutes nothing */
|
||||
break;
|
||||
}
|
||||
}
|
||||
iterate_end(clause_info);
|
||||
return result;
|
||||
|
||||
case CLASS_ATOM:
|
||||
/*
|
||||
* OR-clause R=> atom if each of A's items refutes B
|
||||
*/
|
||||
result = true;
|
||||
iterate_begin(citem, clause, clause_info)
|
||||
{
|
||||
if (!predicate_refuted_by_recurse(citem, predicate))
|
||||
{
|
||||
result = false;
|
||||
break;
|
||||
}
|
||||
}
|
||||
iterate_end(clause_info);
|
||||
return result;
|
||||
}
|
||||
break;
|
||||
|
||||
case CLASS_ATOM:
|
||||
switch (pclass)
|
||||
{
|
||||
case CLASS_AND:
|
||||
/*
|
||||
* atom R=> AND-clause if A refutes any of B's items
|
||||
*/
|
||||
result = false;
|
||||
iterate_begin(pitem, predicate, pred_info)
|
||||
{
|
||||
if (predicate_refuted_by_recurse(clause, pitem))
|
||||
{
|
||||
result = true;
|
||||
break;
|
||||
}
|
||||
}
|
||||
iterate_end(pred_info);
|
||||
return result;
|
||||
|
||||
case CLASS_OR:
|
||||
/*
|
||||
* atom R=> OR-clause if A refutes each of B's items
|
||||
*/
|
||||
result = true;
|
||||
iterate_begin(pitem, predicate, pred_info)
|
||||
{
|
||||
if (!predicate_refuted_by_recurse(clause, pitem))
|
||||
{
|
||||
result = false;
|
||||
break;
|
||||
}
|
||||
}
|
||||
iterate_end(pred_info);
|
||||
return result;
|
||||
|
||||
case CLASS_ATOM:
|
||||
/*
|
||||
* atom R=> atom is the base case
|
||||
*/
|
||||
return
|
||||
predicate_refuted_by_simple_clause((Expr *) predicate,
|
||||
clause);
|
||||
}
|
||||
break;
|
||||
}
|
||||
|
||||
/* can't get here */
|
||||
elog(ERROR, "predicate_classify returned a bogus value");
|
||||
return false;
|
||||
}
|
||||
|
||||
|
||||
/*
|
||||
* predicate_classify
|
||||
* Classify an expression node as AND-type, OR-type, or neither (an atom).
|
||||
*
|
||||
* If the expression is classified as AND- or OR-type, then *info is filled
|
||||
* in with the functions needed to iterate over its components.
|
||||
*/
|
||||
static PredClass
|
||||
predicate_classify(Node *clause, PredIterInfo info)
|
||||
{
|
||||
/* Caller should not pass us NULL, nor a RestrictInfo clause */
|
||||
Assert(clause != NULL);
|
||||
Assert(!IsA(clause, RestrictInfo));
|
||||
|
||||
/*
|
||||
* If we see a List, assume it's an implicit-AND list; this is the
|
||||
* correct semantics for lists of RestrictInfo nodes.
|
||||
*/
|
||||
if (IsA(clause, List))
|
||||
{
|
||||
info->startup_fn = list_startup_fn;
|
||||
info->next_fn = list_next_fn;
|
||||
info->cleanup_fn = list_cleanup_fn;
|
||||
return CLASS_AND;
|
||||
}
|
||||
|
||||
/* Handle normal AND and OR boolean clauses */
|
||||
if (and_clause(clause))
|
||||
{
|
||||
info->startup_fn = boolexpr_startup_fn;
|
||||
info->next_fn = list_next_fn;
|
||||
info->cleanup_fn = list_cleanup_fn;
|
||||
return CLASS_AND;
|
||||
}
|
||||
if (or_clause(clause))
|
||||
{
|
||||
info->startup_fn = boolexpr_startup_fn;
|
||||
info->next_fn = list_next_fn;
|
||||
info->cleanup_fn = list_cleanup_fn;
|
||||
return CLASS_OR;
|
||||
}
|
||||
|
||||
/* Handle ScalarArrayOpExpr */
|
||||
if (IsA(clause, ScalarArrayOpExpr))
|
||||
{
|
||||
ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) clause;
|
||||
Node *arraynode = (Node *) lsecond(saop->args);
|
||||
|
||||
/*
|
||||
* We can break this down into an AND or OR structure, but only if
|
||||
* we know how to iterate through expressions for the array's
|
||||
* elements. We can do that if the array operand is a non-null
|
||||
* constant or a simple ArrayExpr.
|
||||
*/
|
||||
if (arraynode && IsA(arraynode, Const) &&
|
||||
!((Const *) arraynode)->constisnull)
|
||||
{
|
||||
info->startup_fn = arrayconst_startup_fn;
|
||||
info->next_fn = arrayconst_next_fn;
|
||||
info->cleanup_fn = arrayconst_cleanup_fn;
|
||||
return saop->useOr ? CLASS_OR : CLASS_AND;
|
||||
}
|
||||
if (arraynode && IsA(arraynode, ArrayExpr) &&
|
||||
!((ArrayExpr *) arraynode)->multidims)
|
||||
{
|
||||
info->startup_fn = arrayexpr_startup_fn;
|
||||
info->next_fn = arrayexpr_next_fn;
|
||||
info->cleanup_fn = arrayexpr_cleanup_fn;
|
||||
return saop->useOr ? CLASS_OR : CLASS_AND;
|
||||
}
|
||||
}
|
||||
|
||||
/* None of the above, so it's an atom */
|
||||
return CLASS_ATOM;
|
||||
}
|
||||
|
||||
/*
|
||||
* PredIterInfo routines for iterating over regular Lists. The iteration
|
||||
* state variable is the next ListCell to visit.
|
||||
*/
|
||||
static void
|
||||
list_startup_fn(Node *clause, PredIterInfo info)
|
||||
{
|
||||
info->state = (void *) list_head((List *) clause);
|
||||
}
|
||||
|
||||
static Node *
|
||||
list_next_fn(PredIterInfo info)
|
||||
{
|
||||
ListCell *l = (ListCell *) info->state;
|
||||
Node *n;
|
||||
|
||||
if (l == NULL)
|
||||
return NULL;
|
||||
n = lfirst(l);
|
||||
info->state = (void *) lnext(l);
|
||||
return n;
|
||||
}
|
||||
|
||||
static void
|
||||
list_cleanup_fn(PredIterInfo info)
|
||||
{
|
||||
/* Nothing to clean up */
|
||||
}
|
||||
|
||||
/*
|
||||
* BoolExpr needs its own startup function, but can use list_next_fn and
|
||||
* list_cleanup_fn.
|
||||
*/
|
||||
static void
|
||||
boolexpr_startup_fn(Node *clause, PredIterInfo info)
|
||||
{
|
||||
info->state = (void *) list_head(((BoolExpr *) clause)->args);
|
||||
}
|
||||
|
||||
/*
|
||||
* PredIterInfo routines for iterating over a ScalarArrayOpExpr with a
|
||||
* constant array operand.
|
||||
*/
|
||||
typedef struct
|
||||
{
|
||||
OpExpr opexpr;
|
||||
Const constexpr;
|
||||
int next_elem;
|
||||
int num_elems;
|
||||
Datum *elem_values;
|
||||
bool *elem_nulls;
|
||||
} ArrayConstIterState;
|
||||
|
||||
static void
|
||||
arrayconst_startup_fn(Node *clause, PredIterInfo info)
|
||||
{
|
||||
ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) clause;
|
||||
ArrayConstIterState *state;
|
||||
Const *arrayconst;
|
||||
ArrayType *arrayval;
|
||||
int16 elmlen;
|
||||
bool elmbyval;
|
||||
char elmalign;
|
||||
|
||||
/* Create working state struct */
|
||||
state = (ArrayConstIterState *) palloc(sizeof(ArrayConstIterState));
|
||||
info->state = (void *) state;
|
||||
|
||||
/* Deconstruct the array literal */
|
||||
arrayconst = (Const *) lsecond(saop->args);
|
||||
arrayval = DatumGetArrayTypeP(arrayconst->constvalue);
|
||||
get_typlenbyvalalign(ARR_ELEMTYPE(arrayval),
|
||||
&elmlen, &elmbyval, &elmalign);
|
||||
deconstruct_array(arrayval,
|
||||
ARR_ELEMTYPE(arrayval),
|
||||
elmlen, elmbyval, elmalign,
|
||||
&state->elem_values, &state->elem_nulls,
|
||||
&state->num_elems);
|
||||
|
||||
/* Set up a dummy OpExpr to return as the per-item node */
|
||||
state->opexpr.xpr.type = T_OpExpr;
|
||||
state->opexpr.opno = saop->opno;
|
||||
state->opexpr.opfuncid = saop->opfuncid;
|
||||
state->opexpr.opresulttype = BOOLOID;
|
||||
state->opexpr.opretset = false;
|
||||
state->opexpr.args = list_copy(saop->args);
|
||||
|
||||
/* Set up a dummy Const node to hold the per-element values */
|
||||
state->constexpr.xpr.type = T_Const;
|
||||
state->constexpr.consttype = ARR_ELEMTYPE(arrayval);
|
||||
state->constexpr.constlen = elmlen;
|
||||
state->constexpr.constbyval = elmbyval;
|
||||
lsecond(state->opexpr.args) = &state->constexpr;
|
||||
|
||||
/* Initialize iteration state */
|
||||
state->next_elem = 0;
|
||||
}
|
||||
|
||||
static Node *
|
||||
arrayconst_next_fn(PredIterInfo info)
|
||||
{
|
||||
ArrayConstIterState *state = (ArrayConstIterState *) info->state;
|
||||
|
||||
if (state->next_elem >= state->num_elems)
|
||||
return NULL;
|
||||
state->constexpr.constvalue = state->elem_values[state->next_elem];
|
||||
state->constexpr.constisnull = state->elem_nulls[state->next_elem];
|
||||
state->next_elem++;
|
||||
return (Node *) &(state->opexpr);
|
||||
}
|
||||
|
||||
static void
|
||||
arrayconst_cleanup_fn(PredIterInfo info)
|
||||
{
|
||||
ArrayConstIterState *state = (ArrayConstIterState *) info->state;
|
||||
|
||||
pfree(state->elem_values);
|
||||
pfree(state->elem_nulls);
|
||||
list_free(state->opexpr.args);
|
||||
pfree(state);
|
||||
}
|
||||
|
||||
/*
|
||||
* PredIterInfo routines for iterating over a ScalarArrayOpExpr with a
|
||||
* one-dimensional ArrayExpr array operand.
|
||||
*/
|
||||
typedef struct
|
||||
{
|
||||
OpExpr opexpr;
|
||||
ListCell *next;
|
||||
} ArrayExprIterState;
|
||||
|
||||
static void
|
||||
arrayexpr_startup_fn(Node *clause, PredIterInfo info)
|
||||
{
|
||||
ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) clause;
|
||||
ArrayExprIterState *state;
|
||||
ArrayExpr *arrayexpr;
|
||||
|
||||
/* Create working state struct */
|
||||
state = (ArrayExprIterState *) palloc(sizeof(ArrayExprIterState));
|
||||
info->state = (void *) state;
|
||||
|
||||
/* Set up a dummy OpExpr to return as the per-item node */
|
||||
state->opexpr.xpr.type = T_OpExpr;
|
||||
state->opexpr.opno = saop->opno;
|
||||
state->opexpr.opfuncid = saop->opfuncid;
|
||||
state->opexpr.opresulttype = BOOLOID;
|
||||
state->opexpr.opretset = false;
|
||||
state->opexpr.args = list_copy(saop->args);
|
||||
|
||||
/* Initialize iteration variable to first member of ArrayExpr */
|
||||
arrayexpr = (ArrayExpr *) lsecond(saop->args);
|
||||
state->next = list_head(arrayexpr->elements);
|
||||
}
|
||||
|
||||
static Node *
|
||||
arrayexpr_next_fn(PredIterInfo info)
|
||||
{
|
||||
ArrayExprIterState *state = (ArrayExprIterState *) info->state;
|
||||
|
||||
if (state->next == NULL)
|
||||
return NULL;
|
||||
lsecond(state->opexpr.args) = lfirst(state->next);
|
||||
state->next = lnext(state->next);
|
||||
return (Node *) &(state->opexpr);
|
||||
}
|
||||
|
||||
static void
|
||||
arrayexpr_cleanup_fn(PredIterInfo info)
|
||||
{
|
||||
ArrayExprIterState *state = (ArrayExprIterState *) info->state;
|
||||
|
||||
list_free(state->opexpr.args);
|
||||
pfree(state);
|
||||
}
|
||||
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user