PostgreSQL Source Code  git master
predtest.c File Reference
#include "postgres.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
#include "executor/executor.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "nodes/pathnodes.h"
#include "optimizer/optimizer.h"
#include "utils/array.h"
#include "utils/inval.h"
#include "utils/lsyscache.h"
#include "utils/syscache.h"
Include dependency graph for predtest.c:

Go to the source code of this file.

Data Structures

struct  PredIterInfoData
 
struct  ArrayConstIterState
 
struct  ArrayExprIterState
 
struct  OprProofCacheKey
 
struct  OprProofCacheEntry
 

Macros

#define MAX_SAOP_ARRAY_SIZE   100
 
#define iterate_begin(item, clause, info)
 
#define iterate_end(info)
 
#define BTLT   BTLessStrategyNumber
 
#define BTLE   BTLessEqualStrategyNumber
 
#define BTEQ   BTEqualStrategyNumber
 
#define BTGE   BTGreaterEqualStrategyNumber
 
#define BTGT   BTGreaterStrategyNumber
 
#define BTNE   ROWCOMPARE_NE
 
#define none   0
 

Typedefs

typedef struct PredIterInfoDataPredIterInfo
 
typedef struct PredIterInfoData PredIterInfoData
 
typedef struct OprProofCacheKey OprProofCacheKey
 
typedef struct OprProofCacheEntry OprProofCacheEntry
 

Enumerations

enum  PredClass { CLASS_ATOM , CLASS_AND , CLASS_OR }
 

Functions

static bool predicate_implied_by_recurse (Node *clause, Node *predicate, bool weak)
 
static bool predicate_refuted_by_recurse (Node *clause, Node *predicate, bool weak)
 
static PredClass predicate_classify (Node *clause, PredIterInfo info)
 
static void list_startup_fn (Node *clause, PredIterInfo info)
 
static Nodelist_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 Nodearrayconst_next_fn (PredIterInfo info)
 
static void arrayconst_cleanup_fn (PredIterInfo info)
 
static void arrayexpr_startup_fn (Node *clause, PredIterInfo info)
 
static Nodearrayexpr_next_fn (PredIterInfo info)
 
static void arrayexpr_cleanup_fn (PredIterInfo info)
 
static bool predicate_implied_by_simple_clause (Expr *predicate, Node *clause, bool weak)
 
static bool predicate_refuted_by_simple_clause (Expr *predicate, Node *clause, bool weak)
 
static Nodeextract_not_arg (Node *clause)
 
static Nodeextract_strong_not_arg (Node *clause)
 
static bool clause_is_strict_for (Node *clause, Node *subexpr, bool allow_false)
 
static bool operator_predicate_proof (Expr *predicate, Node *clause, bool refute_it, bool weak)
 
static bool operator_same_subexprs_proof (Oid pred_op, Oid clause_op, bool refute_it)
 
static bool operator_same_subexprs_lookup (Oid pred_op, Oid clause_op, bool refute_it)
 
static Oid get_btree_test_op (Oid pred_op, Oid clause_op, bool refute_it)
 
static void InvalidateOprProofCacheCallBack (Datum arg, int cacheid, uint32 hashvalue)
 
bool predicate_implied_by (List *predicate_list, List *clause_list, bool weak)
 
bool predicate_refuted_by (List *predicate_list, List *clause_list, bool weak)
 
static OprProofCacheEntrylookup_proof_cache (Oid pred_op, Oid clause_op, bool refute_it)
 

Variables

static const bool BT_implies_table [6][6]
 
static const bool BT_refutes_table [6][6]
 
static const StrategyNumber BT_implic_table [6][6]
 
static const StrategyNumber BT_refute_table [6][6]
 
static HTABOprProofCacheHash = NULL
 

Macro Definition Documentation

◆ BTEQ

#define BTEQ   BTEqualStrategyNumber

Definition at line 1571 of file predtest.c.

◆ BTGE

#define BTGE   BTGreaterEqualStrategyNumber

Definition at line 1572 of file predtest.c.

◆ BTGT

#define BTGT   BTGreaterStrategyNumber

Definition at line 1573 of file predtest.c.

◆ BTLE

#define BTLE   BTLessEqualStrategyNumber

Definition at line 1570 of file predtest.c.

◆ BTLT

#define BTLT   BTLessStrategyNumber

Definition at line 1569 of file predtest.c.

◆ BTNE

#define BTNE   ROWCOMPARE_NE

Definition at line 1574 of file predtest.c.

◆ iterate_begin

#define iterate_begin (   item,
  clause,
  info 
)
Value:
do { \
Node *item; \
(info).startup_fn((clause), &(info)); \
while ((item = (info).next_fn(&(info))) != NULL)

Definition at line 72 of file predtest.c.

◆ iterate_end

#define iterate_end (   info)
Value:
(info).cleanup_fn(&(info)); \
} while (0)

Definition at line 78 of file predtest.c.

◆ MAX_SAOP_ARRAY_SIZE

#define MAX_SAOP_ARRAY_SIZE   100

Definition at line 40 of file predtest.c.

◆ none

#define none   0

Definition at line 1577 of file predtest.c.

Typedef Documentation

◆ OprProofCacheEntry

◆ OprProofCacheKey

◆ PredIterInfo

typedef struct PredIterInfoData* PredIterInfo

Definition at line 57 of file predtest.c.

◆ PredIterInfoData

Enumeration Type Documentation

◆ PredClass

enum PredClass
Enumerator
CLASS_ATOM 
CLASS_AND 
CLASS_OR 

Definition at line 50 of file predtest.c.

51 {
52  CLASS_ATOM, /* expression that's not AND or OR */
53  CLASS_AND, /* expression with AND semantics */
54  CLASS_OR, /* expression with OR semantics */
55 } PredClass;
PredClass
Definition: predtest.c:51
@ CLASS_AND
Definition: predtest.c:53
@ CLASS_OR
Definition: predtest.c:54
@ CLASS_ATOM
Definition: predtest.c:52

Function Documentation

◆ arrayconst_cleanup_fn()

static void arrayconst_cleanup_fn ( PredIterInfo  info)
static

Definition at line 1021 of file predtest.c.

1022 {
1024 
1025  pfree(state->elem_values);
1026  pfree(state->elem_nulls);
1027  list_free(state->opexpr.args);
1028  pfree(state);
1029 }
void list_free(List *list)
Definition: list.c:1546
void pfree(void *pointer)
Definition: mcxt.c:1508
void * state
Definition: predtest.c:62
Definition: regguts.h:323

References list_free(), pfree(), and PredIterInfoData::state.

Referenced by predicate_classify().

◆ arrayconst_next_fn()

static Node * arrayconst_next_fn ( PredIterInfo  info)
static

Definition at line 1008 of file predtest.c.

1009 {
1011 
1012  if (state->next_elem >= state->num_elems)
1013  return NULL;
1014  state->constexpr.constvalue = state->elem_values[state->next_elem];
1015  state->constexpr.constisnull = state->elem_nulls[state->next_elem];
1016  state->next_elem++;
1017  return (Node *) &(state->opexpr);
1018 }
if(TABLE==NULL||TABLE_index==NULL)
Definition: isn.c:77
Definition: nodes.h:129

References if(), and PredIterInfoData::state.

Referenced by predicate_classify().

◆ arrayconst_startup_fn()

static void arrayconst_startup_fn ( Node clause,
PredIterInfo  info 
)
static

Definition at line 959 of file predtest.c.

960 {
961  ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) clause;
963  Const *arrayconst;
964  ArrayType *arrayval;
965  int16 elmlen;
966  bool elmbyval;
967  char elmalign;
968 
969  /* Create working state struct */
971  info->state = (void *) state;
972 
973  /* Deconstruct the array literal */
974  arrayconst = (Const *) lsecond(saop->args);
975  arrayval = DatumGetArrayTypeP(arrayconst->constvalue);
977  &elmlen, &elmbyval, &elmalign);
978  deconstruct_array(arrayval,
979  ARR_ELEMTYPE(arrayval),
980  elmlen, elmbyval, elmalign,
981  &state->elem_values, &state->elem_nulls,
982  &state->num_elems);
983 
984  /* Set up a dummy OpExpr to return as the per-item node */
985  state->opexpr.xpr.type = T_OpExpr;
986  state->opexpr.opno = saop->opno;
987  state->opexpr.opfuncid = saop->opfuncid;
988  state->opexpr.opresulttype = BOOLOID;
989  state->opexpr.opretset = false;
990  state->opexpr.opcollid = InvalidOid;
991  state->opexpr.inputcollid = saop->inputcollid;
992  state->opexpr.args = list_copy(saop->args);
993 
994  /* Set up a dummy Const node to hold the per-element values */
995  state->constexpr.xpr.type = T_Const;
996  state->constexpr.consttype = ARR_ELEMTYPE(arrayval);
997  state->constexpr.consttypmod = -1;
998  state->constexpr.constcollid = arrayconst->constcollid;
999  state->constexpr.constlen = elmlen;
1000  state->constexpr.constbyval = elmbyval;
1001  lsecond(state->opexpr.args) = &state->constexpr;
1002 
1003  /* Initialize iteration state */
1004  state->next_elem = 0;
1005 }
#define DatumGetArrayTypeP(X)
Definition: array.h:261
#define ARR_ELEMTYPE(a)
Definition: array.h:292
void deconstruct_array(ArrayType *array, Oid elmtype, int elmlen, bool elmbyval, char elmalign, Datum **elemsp, bool **nullsp, int *nelemsp)
Definition: arrayfuncs.c:3612
signed short int16
Definition: c.h:480
List * list_copy(const List *oldlist)
Definition: list.c:1573
void get_typlenbyvalalign(Oid typid, int16 *typlen, bool *typbyval, char *typalign)
Definition: lsyscache.c:2227
void * palloc(Size size)
Definition: mcxt.c:1304
#define lsecond(l)
Definition: pg_list.h:183
#define InvalidOid
Definition: postgres_ext.h:36

References ScalarArrayOpExpr::args, ARR_ELEMTYPE, DatumGetArrayTypeP, deconstruct_array(), get_typlenbyvalalign(), InvalidOid, list_copy(), lsecond, ScalarArrayOpExpr::opno, palloc(), and PredIterInfoData::state.

Referenced by predicate_classify().

◆ arrayexpr_cleanup_fn()

static void arrayexpr_cleanup_fn ( PredIterInfo  info)
static

Definition at line 1081 of file predtest.c.

1082 {
1084 
1085  list_free(state->opexpr.args);
1086  pfree(state);
1087 }

References list_free(), pfree(), and PredIterInfoData::state.

Referenced by predicate_classify().

◆ arrayexpr_next_fn()

static Node * arrayexpr_next_fn ( PredIterInfo  info)
static

Definition at line 1069 of file predtest.c.

1070 {
1072 
1073  if (state->next == NULL)
1074  return NULL;
1075  lsecond(state->opexpr.args) = lfirst(state->next);
1076  state->next = lnext(info->state_list, state->next);
1077  return (Node *) &(state->opexpr);
1078 }
#define lfirst(lc)
Definition: pg_list.h:172
static ListCell * lnext(const List *l, const ListCell *c)
Definition: pg_list.h:343
List * state_list
Definition: predtest.c:63
struct state * next
Definition: regguts.h:332

References if(), lfirst, lnext(), lsecond, state::next, PredIterInfoData::state, and PredIterInfoData::state_list.

Referenced by predicate_classify().

◆ arrayexpr_startup_fn()

static void arrayexpr_startup_fn ( Node clause,
PredIterInfo  info 
)
static

Definition at line 1042 of file predtest.c.

1043 {
1044  ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) clause;
1046  ArrayExpr *arrayexpr;
1047 
1048  /* Create working state struct */
1050  info->state = (void *) state;
1051 
1052  /* Set up a dummy OpExpr to return as the per-item node */
1053  state->opexpr.xpr.type = T_OpExpr;
1054  state->opexpr.opno = saop->opno;
1055  state->opexpr.opfuncid = saop->opfuncid;
1056  state->opexpr.opresulttype = BOOLOID;
1057  state->opexpr.opretset = false;
1058  state->opexpr.opcollid = InvalidOid;
1059  state->opexpr.inputcollid = saop->inputcollid;
1060  state->opexpr.args = list_copy(saop->args);
1061 
1062  /* Initialize iteration variable to first member of ArrayExpr */
1063  arrayexpr = (ArrayExpr *) lsecond(saop->args);
1064  info->state_list = arrayexpr->elements;
1065  state->next = list_head(arrayexpr->elements);
1066 }
static ListCell * list_head(const List *l)
Definition: pg_list.h:128
List * elements
Definition: primnodes.h:1336

References ScalarArrayOpExpr::args, ArrayExpr::elements, InvalidOid, list_copy(), list_head(), lsecond, state::next, ScalarArrayOpExpr::opno, palloc(), PredIterInfoData::state, and PredIterInfoData::state_list.

Referenced by predicate_classify().

◆ boolexpr_startup_fn()

static void boolexpr_startup_fn ( Node clause,
PredIterInfo  info 
)
static

Definition at line 938 of file predtest.c.

939 {
940  info->state_list = ((BoolExpr *) clause)->args;
941  info->state = (void *) list_head(info->state_list);
942 }

References list_head(), PredIterInfoData::state, and PredIterInfoData::state_list.

Referenced by predicate_classify().

◆ clause_is_strict_for()

static bool clause_is_strict_for ( Node clause,
Node subexpr,
bool  allow_false 
)
static

Definition at line 1367 of file predtest.c.

1368 {
1369  ListCell *lc;
1370 
1371  /* safety checks */
1372  if (clause == NULL || subexpr == NULL)
1373  return false;
1374 
1375  /*
1376  * Look through any RelabelType nodes, so that we can match, say,
1377  * varcharcol with lower(varcharcol::text). (In general we could recurse
1378  * through any nullness-preserving, immutable operation.) We should not
1379  * see stacked RelabelTypes here.
1380  */
1381  if (IsA(clause, RelabelType))
1382  clause = (Node *) ((RelabelType *) clause)->arg;
1383  if (IsA(subexpr, RelabelType))
1384  subexpr = (Node *) ((RelabelType *) subexpr)->arg;
1385 
1386  /* Base case */
1387  if (equal(clause, subexpr))
1388  return true;
1389 
1390  /*
1391  * If we have a strict operator or function, a NULL result is guaranteed
1392  * if any input is forced NULL by subexpr. This is OK even if the op or
1393  * func isn't immutable, since it won't even be called on NULL input.
1394  */
1395  if (is_opclause(clause) &&
1396  op_strict(((OpExpr *) clause)->opno))
1397  {
1398  foreach(lc, ((OpExpr *) clause)->args)
1399  {
1400  if (clause_is_strict_for((Node *) lfirst(lc), subexpr, false))
1401  return true;
1402  }
1403  return false;
1404  }
1405  if (is_funcclause(clause) &&
1406  func_strict(((FuncExpr *) clause)->funcid))
1407  {
1408  foreach(lc, ((FuncExpr *) clause)->args)
1409  {
1410  if (clause_is_strict_for((Node *) lfirst(lc), subexpr, false))
1411  return true;
1412  }
1413  return false;
1414  }
1415 
1416  /*
1417  * CoerceViaIO is strict (whether or not the I/O functions it calls are).
1418  * Likewise, ArrayCoerceExpr is strict for its array argument (regardless
1419  * of what the per-element expression is), ConvertRowtypeExpr is strict at
1420  * the row level, and CoerceToDomain is strict too. These are worth
1421  * checking mainly because it saves us having to explain to users why some
1422  * type coercions are known strict and others aren't.
1423  */
1424  if (IsA(clause, CoerceViaIO))
1425  return clause_is_strict_for((Node *) ((CoerceViaIO *) clause)->arg,
1426  subexpr, false);
1427  if (IsA(clause, ArrayCoerceExpr))
1428  return clause_is_strict_for((Node *) ((ArrayCoerceExpr *) clause)->arg,
1429  subexpr, false);
1430  if (IsA(clause, ConvertRowtypeExpr))
1431  return clause_is_strict_for((Node *) ((ConvertRowtypeExpr *) clause)->arg,
1432  subexpr, false);
1433  if (IsA(clause, CoerceToDomain))
1434  return clause_is_strict_for((Node *) ((CoerceToDomain *) clause)->arg,
1435  subexpr, false);
1436 
1437  /*
1438  * ScalarArrayOpExpr is a special case. Note that we'd only reach here
1439  * with a ScalarArrayOpExpr clause if we failed to deconstruct it into an
1440  * AND or OR tree, as for example if it has too many array elements.
1441  */
1442  if (IsA(clause, ScalarArrayOpExpr))
1443  {
1444  ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) clause;
1445  Node *scalarnode = (Node *) linitial(saop->args);
1446  Node *arraynode = (Node *) lsecond(saop->args);
1447 
1448  /*
1449  * If we can prove the scalar input to be null, and the operator is
1450  * strict, then the SAOP result has to be null --- unless the array is
1451  * empty. For an empty array, we'd get either false (for ANY) or true
1452  * (for ALL). So if allow_false = true then the proof succeeds anyway
1453  * for the ANY case; otherwise we can only make the proof if we can
1454  * prove the array non-empty.
1455  */
1456  if (clause_is_strict_for(scalarnode, subexpr, false) &&
1457  op_strict(saop->opno))
1458  {
1459  int nelems = 0;
1460 
1461  if (allow_false && saop->useOr)
1462  return true; /* can succeed even if array is empty */
1463 
1464  if (arraynode && IsA(arraynode, Const))
1465  {
1466  Const *arrayconst = (Const *) arraynode;
1467  ArrayType *arrval;
1468 
1469  /*
1470  * If array is constant NULL then we can succeed, as in the
1471  * case below.
1472  */
1473  if (arrayconst->constisnull)
1474  return true;
1475 
1476  /* Otherwise, we can compute the number of elements. */
1477  arrval = DatumGetArrayTypeP(arrayconst->constvalue);
1478  nelems = ArrayGetNItems(ARR_NDIM(arrval), ARR_DIMS(arrval));
1479  }
1480  else if (arraynode && IsA(arraynode, ArrayExpr) &&
1481  !((ArrayExpr *) arraynode)->multidims)
1482  {
1483  /*
1484  * We can also reliably count the number of array elements if
1485  * the input is a non-multidim ARRAY[] expression.
1486  */
1487  nelems = list_length(((ArrayExpr *) arraynode)->elements);
1488  }
1489 
1490  /* Proof succeeds if array is definitely non-empty */
1491  if (nelems > 0)
1492  return true;
1493  }
1494 
1495  /*
1496  * If we can prove the array input to be null, the proof succeeds in
1497  * all cases, since ScalarArrayOpExpr will always return NULL for a
1498  * NULL array. Otherwise, we're done here.
1499  */
1500  return clause_is_strict_for(arraynode, subexpr, false);
1501  }
1502 
1503  /*
1504  * When recursing into an expression, we might find a NULL constant.
1505  * That's certainly NULL, whether it matches subexpr or not.
1506  */
1507  if (IsA(clause, Const))
1508  return ((Const *) clause)->constisnull;
1509 
1510  return false;
1511 }
#define ARR_NDIM(a)
Definition: array.h:290
#define ARR_DIMS(a)
Definition: array.h:294
int ArrayGetNItems(int ndim, const int *dims)
Definition: arrayutils.c:57
bool equal(const void *a, const void *b)
Definition: equalfuncs.c:223
bool op_strict(Oid opno)
Definition: lsyscache.c:1455
bool func_strict(Oid funcid)
Definition: lsyscache.c:1739
static bool is_opclause(const void *clause)
Definition: nodeFuncs.h:74
static bool is_funcclause(const void *clause)
Definition: nodeFuncs.h:67
#define IsA(nodeptr, _type_)
Definition: nodes.h:158
void * arg
static int list_length(const List *l)
Definition: pg_list.h:152
#define linitial(l)
Definition: pg_list.h:178
static bool clause_is_strict_for(Node *clause, Node *subexpr, bool allow_false)
Definition: predtest.c:1367

References arg, ScalarArrayOpExpr::args, ARR_DIMS, ARR_NDIM, ArrayGetNItems(), DatumGetArrayTypeP, equal(), func_strict(), is_funcclause(), is_opclause(), IsA, lfirst, linitial, list_length(), lsecond, op_strict(), ScalarArrayOpExpr::opno, and ScalarArrayOpExpr::useOr.

Referenced by predicate_implied_by_simple_clause(), and predicate_refuted_by_simple_clause().

◆ extract_not_arg()

static Node * extract_not_arg ( Node clause)
static

Definition at line 1293 of file predtest.c.

1294 {
1295  if (clause == NULL)
1296  return NULL;
1297  if (IsA(clause, BoolExpr))
1298  {
1299  BoolExpr *bexpr = (BoolExpr *) clause;
1300 
1301  if (bexpr->boolop == NOT_EXPR)
1302  return (Node *) linitial(bexpr->args);
1303  }
1304  else if (IsA(clause, BooleanTest))
1305  {
1306  BooleanTest *btest = (BooleanTest *) clause;
1307 
1308  if (btest->booltesttype == IS_NOT_TRUE ||
1309  btest->booltesttype == IS_FALSE ||
1310  btest->booltesttype == IS_UNKNOWN)
1311  return (Node *) btest->arg;
1312  }
1313  return NULL;
1314 }
@ IS_NOT_TRUE
Definition: primnodes.h:1739
@ IS_UNKNOWN
Definition: primnodes.h:1739
@ IS_FALSE
Definition: primnodes.h:1739
@ NOT_EXPR
Definition: primnodes.h:887
BoolExprType boolop
Definition: primnodes.h:895
List * args
Definition: primnodes.h:896
BoolTestType booltesttype
Definition: primnodes.h:1746
Expr * arg
Definition: primnodes.h:1745

References BooleanTest::arg, BoolExpr::args, BoolExpr::boolop, BooleanTest::booltesttype, IS_FALSE, IS_NOT_TRUE, IS_UNKNOWN, IsA, linitial, and NOT_EXPR.

Referenced by predicate_refuted_by_recurse().

◆ extract_strong_not_arg()

static Node * extract_strong_not_arg ( Node clause)
static

Definition at line 1321 of file predtest.c.

1322 {
1323  if (clause == NULL)
1324  return NULL;
1325  if (IsA(clause, BoolExpr))
1326  {
1327  BoolExpr *bexpr = (BoolExpr *) clause;
1328 
1329  if (bexpr->boolop == NOT_EXPR)
1330  return (Node *) linitial(bexpr->args);
1331  }
1332  else if (IsA(clause, BooleanTest))
1333  {
1334  BooleanTest *btest = (BooleanTest *) clause;
1335 
1336  if (btest->booltesttype == IS_FALSE)
1337  return (Node *) btest->arg;
1338  }
1339  return NULL;
1340 }

References BooleanTest::arg, BoolExpr::args, BoolExpr::boolop, BooleanTest::booltesttype, IS_FALSE, IsA, linitial, and NOT_EXPR.

Referenced by predicate_refuted_by_recurse().

◆ get_btree_test_op()

static Oid get_btree_test_op ( Oid  pred_op,
Oid  clause_op,
bool  refute_it 
)
static

Definition at line 2237 of file predtest.c.

2238 {
2239  OprProofCacheEntry *cache_entry;
2240 
2241  cache_entry = lookup_proof_cache(pred_op, clause_op, refute_it);
2242  if (refute_it)
2243  return cache_entry->refute_test_op;
2244  else
2245  return cache_entry->implic_test_op;
2246 }
static OprProofCacheEntry * lookup_proof_cache(Oid pred_op, Oid clause_op, bool refute_it)
Definition: predtest.c:2008

References OprProofCacheEntry::implic_test_op, lookup_proof_cache(), and OprProofCacheEntry::refute_test_op.

Referenced by operator_predicate_proof().

◆ InvalidateOprProofCacheCallBack()

static void InvalidateOprProofCacheCallBack ( Datum  arg,
int  cacheid,
uint32  hashvalue 
)
static

Definition at line 2253 of file predtest.c.

2254 {
2255  HASH_SEQ_STATUS status;
2256  OprProofCacheEntry *hentry;
2257 
2258  Assert(OprProofCacheHash != NULL);
2259 
2260  /* Currently we just reset all entries; hard to be smarter ... */
2261  hash_seq_init(&status, OprProofCacheHash);
2262 
2263  while ((hentry = (OprProofCacheEntry *) hash_seq_search(&status)) != NULL)
2264  {
2265  hentry->have_implic = false;
2266  hentry->have_refute = false;
2267  }
2268 }
void * hash_seq_search(HASH_SEQ_STATUS *status)
Definition: dynahash.c:1395
void hash_seq_init(HASH_SEQ_STATUS *status, HTAB *hashp)
Definition: dynahash.c:1385
Assert(fmt[strlen(fmt) - 1] !='\n')
static HTAB * OprProofCacheHash
Definition: predtest.c:2000

References Assert(), hash_seq_init(), hash_seq_search(), OprProofCacheEntry::have_implic, OprProofCacheEntry::have_refute, and OprProofCacheHash.

Referenced by lookup_proof_cache().

◆ list_cleanup_fn()

static void list_cleanup_fn ( PredIterInfo  info)
static

Definition at line 928 of file predtest.c.

929 {
930  /* Nothing to clean up */
931 }

Referenced by predicate_classify().

◆ list_next_fn()

static Node * list_next_fn ( PredIterInfo  info)
static

Definition at line 915 of file predtest.c.

916 {
917  ListCell *l = (ListCell *) info->state;
918  Node *n;
919 
920  if (l == NULL)
921  return NULL;
922  n = lfirst(l);
923  info->state = (void *) lnext(info->state_list, l);
924  return n;
925 }

References if(), lfirst, lnext(), PredIterInfoData::state, and PredIterInfoData::state_list.

Referenced by predicate_classify().

◆ list_startup_fn()

static void list_startup_fn ( Node clause,
PredIterInfo  info 
)
static

Definition at line 908 of file predtest.c.

909 {
910  info->state_list = (List *) clause;
911  info->state = (void *) list_head(info->state_list);
912 }
Definition: pg_list.h:54

References list_head(), PredIterInfoData::state, and PredIterInfoData::state_list.

Referenced by predicate_classify().

◆ lookup_proof_cache()

static OprProofCacheEntry* lookup_proof_cache ( Oid  pred_op,
Oid  clause_op,
bool  refute_it 
)
static

Definition at line 2008 of file predtest.c.

2009 {
2011  OprProofCacheEntry *cache_entry;
2012  bool cfound;
2013  bool same_subexprs = false;
2014  Oid test_op = InvalidOid;
2015  bool found = false;
2016  List *pred_op_infos,
2017  *clause_op_infos;
2018  ListCell *lcp,
2019  *lcc;
2020 
2021  /*
2022  * Find or make a cache entry for this pair of operators.
2023  */
2024  if (OprProofCacheHash == NULL)
2025  {
2026  /* First time through: initialize the hash table */
2027  HASHCTL ctl;
2028 
2029  ctl.keysize = sizeof(OprProofCacheKey);
2030  ctl.entrysize = sizeof(OprProofCacheEntry);
2031  OprProofCacheHash = hash_create("Btree proof lookup cache", 256,
2032  &ctl, HASH_ELEM | HASH_BLOBS);
2033 
2034  /* Arrange to flush cache on pg_amop changes */
2037  (Datum) 0);
2038  }
2039 
2040  key.pred_op = pred_op;
2041  key.clause_op = clause_op;
2043  &key,
2044  HASH_ENTER, &cfound);
2045  if (!cfound)
2046  {
2047  /* new cache entry, set it invalid */
2048  cache_entry->have_implic = false;
2049  cache_entry->have_refute = false;
2050  }
2051  else
2052  {
2053  /* pre-existing cache entry, see if we know the answer yet */
2054  if (refute_it ? cache_entry->have_refute : cache_entry->have_implic)
2055  return cache_entry;
2056  }
2057 
2058  /*
2059  * Try to find a btree opfamily containing the given operators.
2060  *
2061  * We must find a btree opfamily that contains both operators, else the
2062  * implication can't be determined. Also, the opfamily must contain a
2063  * suitable test operator taking the operators' righthand datatypes.
2064  *
2065  * If there are multiple matching opfamilies, assume we can use any one to
2066  * determine the logical relationship of the two operators and the correct
2067  * corresponding test operator. This should work for any logically
2068  * consistent opfamilies.
2069  *
2070  * Note that we can determine the operators' relationship for
2071  * same-subexprs cases even from an opfamily that lacks a usable test
2072  * operator. This can happen in cases with incomplete sets of cross-type
2073  * comparison operators.
2074  */
2075  clause_op_infos = get_op_btree_interpretation(clause_op);
2076  if (clause_op_infos)
2077  pred_op_infos = get_op_btree_interpretation(pred_op);
2078  else /* no point in looking */
2079  pred_op_infos = NIL;
2080 
2081  foreach(lcp, pred_op_infos)
2082  {
2083  OpBtreeInterpretation *pred_op_info = lfirst(lcp);
2084  Oid opfamily_id = pred_op_info->opfamily_id;
2085 
2086  foreach(lcc, clause_op_infos)
2087  {
2088  OpBtreeInterpretation *clause_op_info = lfirst(lcc);
2089  StrategyNumber pred_strategy,
2090  clause_strategy,
2091  test_strategy;
2092 
2093  /* Must find them in same opfamily */
2094  if (opfamily_id != clause_op_info->opfamily_id)
2095  continue;
2096  /* Lefttypes should match */
2097  Assert(clause_op_info->oplefttype == pred_op_info->oplefttype);
2098 
2099  pred_strategy = pred_op_info->strategy;
2100  clause_strategy = clause_op_info->strategy;
2101 
2102  /*
2103  * Check to see if we can make a proof for same-subexpressions
2104  * cases based on the operators' relationship in this opfamily.
2105  */
2106  if (refute_it)
2107  same_subexprs |= BT_refutes_table[clause_strategy - 1][pred_strategy - 1];
2108  else
2109  same_subexprs |= BT_implies_table[clause_strategy - 1][pred_strategy - 1];
2110 
2111  /*
2112  * Look up the "test" strategy number in the implication table
2113  */
2114  if (refute_it)
2115  test_strategy = BT_refute_table[clause_strategy - 1][pred_strategy - 1];
2116  else
2117  test_strategy = BT_implic_table[clause_strategy - 1][pred_strategy - 1];
2118 
2119  if (test_strategy == 0)
2120  {
2121  /* Can't determine implication using this interpretation */
2122  continue;
2123  }
2124 
2125  /*
2126  * See if opfamily has an operator for the test strategy and the
2127  * datatypes.
2128  */
2129  if (test_strategy == BTNE)
2130  {
2131  test_op = get_opfamily_member(opfamily_id,
2132  pred_op_info->oprighttype,
2133  clause_op_info->oprighttype,
2135  if (OidIsValid(test_op))
2136  test_op = get_negator(test_op);
2137  }
2138  else
2139  {
2140  test_op = get_opfamily_member(opfamily_id,
2141  pred_op_info->oprighttype,
2142  clause_op_info->oprighttype,
2143  test_strategy);
2144  }
2145 
2146  if (!OidIsValid(test_op))
2147  continue;
2148 
2149  /*
2150  * Last check: test_op must be immutable.
2151  *
2152  * Note that we require only the test_op to be immutable, not the
2153  * original clause_op. (pred_op is assumed to have been checked
2154  * immutable by the caller.) Essentially we are assuming that the
2155  * opfamily is consistent even if it contains operators that are
2156  * merely stable.
2157  */
2158  if (op_volatile(test_op) == PROVOLATILE_IMMUTABLE)
2159  {
2160  found = true;
2161  break;
2162  }
2163  }
2164 
2165  if (found)
2166  break;
2167  }
2168 
2169  list_free_deep(pred_op_infos);
2170  list_free_deep(clause_op_infos);
2171 
2172  if (!found)
2173  {
2174  /* couldn't find a suitable comparison operator */
2175  test_op = InvalidOid;
2176  }
2177 
2178  /*
2179  * If we think we were able to prove something about same-subexpressions
2180  * cases, check to make sure the clause_op is immutable before believing
2181  * it completely. (Usually, the clause_op would be immutable if the
2182  * pred_op is, but it's not entirely clear that this must be true in all
2183  * cases, so let's check.)
2184  */
2185  if (same_subexprs &&
2186  op_volatile(clause_op) != PROVOLATILE_IMMUTABLE)
2187  same_subexprs = false;
2188 
2189  /* Cache the results, whether positive or negative */
2190  if (refute_it)
2191  {
2192  cache_entry->refute_test_op = test_op;
2193  cache_entry->same_subexprs_refutes = same_subexprs;
2194  cache_entry->have_refute = true;
2195  }
2196  else
2197  {
2198  cache_entry->implic_test_op = test_op;
2199  cache_entry->same_subexprs_implies = same_subexprs;
2200  cache_entry->have_implic = true;
2201  }
2202 
2203  return cache_entry;
2204 }
#define OidIsValid(objectId)
Definition: c.h:762
void * hash_search(HTAB *hashp, const void *keyPtr, HASHACTION action, bool *foundPtr)
Definition: dynahash.c:955
HTAB * hash_create(const char *tabname, long nelem, const HASHCTL *info, int flags)
Definition: dynahash.c:352
@ HASH_ENTER
Definition: hsearch.h:114
#define HASH_ELEM
Definition: hsearch.h:95
#define HASH_BLOBS
Definition: hsearch.h:97
void CacheRegisterSyscacheCallback(int cacheid, SyscacheCallbackFunction func, Datum arg)
Definition: inval.c:1516
void list_free_deep(List *list)
Definition: list.c:1560
Oid get_opfamily_member(Oid opfamily, Oid lefttype, Oid righttype, int16 strategy)
Definition: lsyscache.c:166
List * get_op_btree_interpretation(Oid opno)
Definition: lsyscache.c:601
char op_volatile(Oid opno)
Definition: lsyscache.c:1471
Oid get_negator(Oid opno)
Definition: lsyscache.c:1511
#define NIL
Definition: pg_list.h:68
uintptr_t Datum
Definition: postgres.h:64
unsigned int Oid
Definition: postgres_ext.h:31
static const StrategyNumber BT_refute_table[6][6]
Definition: predtest.c:1618
static void InvalidateOprProofCacheCallBack(Datum arg, int cacheid, uint32 hashvalue)
Definition: predtest.c:2253
struct OprProofCacheEntry OprProofCacheEntry
static const bool BT_refutes_table[6][6]
Definition: predtest.c:1592
#define BTNE
Definition: predtest.c:1574
static const bool BT_implies_table[6][6]
Definition: predtest.c:1579
struct OprProofCacheKey OprProofCacheKey
static const StrategyNumber BT_implic_table[6][6]
Definition: predtest.c:1605
uint16 StrategyNumber
Definition: stratnum.h:22
#define BTEqualStrategyNumber
Definition: stratnum.h:31
Size keysize
Definition: hsearch.h:75
Size entrysize
Definition: hsearch.h:76
bool same_subexprs_refutes
Definition: predtest.c:1995
bool same_subexprs_implies
Definition: predtest.c:1994

References Assert(), BT_implic_table, BT_implies_table, BT_refute_table, BT_refutes_table, BTEqualStrategyNumber, BTNE, CacheRegisterSyscacheCallback(), HASHCTL::entrysize, get_negator(), get_op_btree_interpretation(), get_opfamily_member(), HASH_BLOBS, hash_create(), HASH_ELEM, HASH_ENTER, hash_search(), OprProofCacheEntry::have_implic, OprProofCacheEntry::have_refute, OprProofCacheEntry::implic_test_op, InvalidateOprProofCacheCallBack(), InvalidOid, sort-test::key, HASHCTL::keysize, lfirst, list_free_deep(), NIL, OidIsValid, op_volatile(), OpBtreeInterpretation::opfamily_id, OpBtreeInterpretation::oplefttype, OpBtreeInterpretation::oprighttype, OprProofCacheHash, OprProofCacheEntry::refute_test_op, OprProofCacheEntry::same_subexprs_implies, OprProofCacheEntry::same_subexprs_refutes, and OpBtreeInterpretation::strategy.

Referenced by get_btree_test_op(), and operator_same_subexprs_lookup().

◆ operator_predicate_proof()

static bool operator_predicate_proof ( Expr predicate,
Node clause,
bool  refute_it,
bool  weak 
)
static

Definition at line 1686 of file predtest.c.

1688 {
1689  OpExpr *pred_opexpr,
1690  *clause_opexpr;
1691  Oid pred_collation,
1692  clause_collation;
1693  Oid pred_op,
1694  clause_op,
1695  test_op;
1696  Node *pred_leftop,
1697  *pred_rightop,
1698  *clause_leftop,
1699  *clause_rightop;
1700  Const *pred_const,
1701  *clause_const;
1702  Expr *test_expr;
1703  ExprState *test_exprstate;
1704  Datum test_result;
1705  bool isNull;
1706  EState *estate;
1707  MemoryContext oldcontext;
1708 
1709  /*
1710  * Both expressions must be binary opclauses, else we can't do anything.
1711  *
1712  * Note: in future we might extend this logic to other operator-based
1713  * constructs such as DistinctExpr. But the planner isn't very smart
1714  * about DistinctExpr in general, and this probably isn't the first place
1715  * to fix if you want to improve that.
1716  */
1717  if (!is_opclause(predicate))
1718  return false;
1719  pred_opexpr = (OpExpr *) predicate;
1720  if (list_length(pred_opexpr->args) != 2)
1721  return false;
1722  if (!is_opclause(clause))
1723  return false;
1724  clause_opexpr = (OpExpr *) clause;
1725  if (list_length(clause_opexpr->args) != 2)
1726  return false;
1727 
1728  /*
1729  * If they're marked with different collations then we can't do anything.
1730  * This is a cheap test so let's get it out of the way early.
1731  */
1732  pred_collation = pred_opexpr->inputcollid;
1733  clause_collation = clause_opexpr->inputcollid;
1734  if (pred_collation != clause_collation)
1735  return false;
1736 
1737  /* Grab the operator OIDs now too. We may commute these below. */
1738  pred_op = pred_opexpr->opno;
1739  clause_op = clause_opexpr->opno;
1740 
1741  /*
1742  * We have to match up at least one pair of input expressions.
1743  */
1744  pred_leftop = (Node *) linitial(pred_opexpr->args);
1745  pred_rightop = (Node *) lsecond(pred_opexpr->args);
1746  clause_leftop = (Node *) linitial(clause_opexpr->args);
1747  clause_rightop = (Node *) lsecond(clause_opexpr->args);
1748 
1749  if (equal(pred_leftop, clause_leftop))
1750  {
1751  if (equal(pred_rightop, clause_rightop))
1752  {
1753  /* We have x op1 y and x op2 y */
1754  return operator_same_subexprs_proof(pred_op, clause_op, refute_it);
1755  }
1756  else
1757  {
1758  /* Fail unless rightops are both Consts */
1759  if (pred_rightop == NULL || !IsA(pred_rightop, Const))
1760  return false;
1761  pred_const = (Const *) pred_rightop;
1762  if (clause_rightop == NULL || !IsA(clause_rightop, Const))
1763  return false;
1764  clause_const = (Const *) clause_rightop;
1765  }
1766  }
1767  else if (equal(pred_rightop, clause_rightop))
1768  {
1769  /* Fail unless leftops are both Consts */
1770  if (pred_leftop == NULL || !IsA(pred_leftop, Const))
1771  return false;
1772  pred_const = (Const *) pred_leftop;
1773  if (clause_leftop == NULL || !IsA(clause_leftop, Const))
1774  return false;
1775  clause_const = (Const *) clause_leftop;
1776  /* Commute both operators so we can assume Consts are on the right */
1777  pred_op = get_commutator(pred_op);
1778  if (!OidIsValid(pred_op))
1779  return false;
1780  clause_op = get_commutator(clause_op);
1781  if (!OidIsValid(clause_op))
1782  return false;
1783  }
1784  else if (equal(pred_leftop, clause_rightop))
1785  {
1786  if (equal(pred_rightop, clause_leftop))
1787  {
1788  /* We have x op1 y and y op2 x */
1789  /* Commute pred_op that we can treat this like a straight match */
1790  pred_op = get_commutator(pred_op);
1791  if (!OidIsValid(pred_op))
1792  return false;
1793  return operator_same_subexprs_proof(pred_op, clause_op, refute_it);
1794  }
1795  else
1796  {
1797  /* Fail unless pred_rightop/clause_leftop are both Consts */
1798  if (pred_rightop == NULL || !IsA(pred_rightop, Const))
1799  return false;
1800  pred_const = (Const *) pred_rightop;
1801  if (clause_leftop == NULL || !IsA(clause_leftop, Const))
1802  return false;
1803  clause_const = (Const *) clause_leftop;
1804  /* Commute clause_op so we can assume Consts are on the right */
1805  clause_op = get_commutator(clause_op);
1806  if (!OidIsValid(clause_op))
1807  return false;
1808  }
1809  }
1810  else if (equal(pred_rightop, clause_leftop))
1811  {
1812  /* Fail unless pred_leftop/clause_rightop are both Consts */
1813  if (pred_leftop == NULL || !IsA(pred_leftop, Const))
1814  return false;
1815  pred_const = (Const *) pred_leftop;
1816  if (clause_rightop == NULL || !IsA(clause_rightop, Const))
1817  return false;
1818  clause_const = (Const *) clause_rightop;
1819  /* Commute pred_op so we can assume Consts are on the right */
1820  pred_op = get_commutator(pred_op);
1821  if (!OidIsValid(pred_op))
1822  return false;
1823  }
1824  else
1825  {
1826  /* Failed to match up any of the subexpressions, so we lose */
1827  return false;
1828  }
1829 
1830  /*
1831  * We have two identical subexpressions, and two other subexpressions that
1832  * are not identical but are both Consts; and we have commuted the
1833  * operators if necessary so that the Consts are on the right. We'll need
1834  * to compare the Consts' values. If either is NULL, we can't do that, so
1835  * usually the proof fails ... but in some cases we can claim success.
1836  */
1837  if (clause_const->constisnull)
1838  {
1839  /* If clause_op isn't strict, we can't prove anything */
1840  if (!op_strict(clause_op))
1841  return false;
1842 
1843  /*
1844  * At this point we know that the clause returns NULL. For proof
1845  * types that assume truth of the clause, this means the proof is
1846  * vacuously true (a/k/a "false implies anything"). That's all proof
1847  * types except weak implication.
1848  */
1849  if (!(weak && !refute_it))
1850  return true;
1851 
1852  /*
1853  * For weak implication, it's still possible for the proof to succeed,
1854  * if the predicate can also be proven NULL. In that case we've got
1855  * NULL => NULL which is valid for this proof type.
1856  */
1857  if (pred_const->constisnull && op_strict(pred_op))
1858  return true;
1859  /* Else the proof fails */
1860  return false;
1861  }
1862  if (pred_const->constisnull)
1863  {
1864  /*
1865  * If the pred_op is strict, we know the predicate yields NULL, which
1866  * means the proof succeeds for either weak implication or weak
1867  * refutation.
1868  */
1869  if (weak && op_strict(pred_op))
1870  return true;
1871  /* Else the proof fails */
1872  return false;
1873  }
1874 
1875  /*
1876  * Lookup the constant-comparison operator using the system catalogs and
1877  * the operator implication tables.
1878  */
1879  test_op = get_btree_test_op(pred_op, clause_op, refute_it);
1880 
1881  if (!OidIsValid(test_op))
1882  {
1883  /* couldn't find a suitable comparison operator */
1884  return false;
1885  }
1886 
1887  /*
1888  * Evaluate the test. For this we need an EState.
1889  */
1890  estate = CreateExecutorState();
1891 
1892  /* We can use the estate's working context to avoid memory leaks. */
1893  oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
1894 
1895  /* Build expression tree */
1896  test_expr = make_opclause(test_op,
1897  BOOLOID,
1898  false,
1899  (Expr *) pred_const,
1900  (Expr *) clause_const,
1901  InvalidOid,
1902  pred_collation);
1903 
1904  /* Fill in opfuncids */
1905  fix_opfuncids((Node *) test_expr);
1906 
1907  /* Prepare it for execution */
1908  test_exprstate = ExecInitExpr(test_expr, NULL);
1909 
1910  /* And execute it. */
1911  test_result = ExecEvalExprSwitchContext(test_exprstate,
1912  GetPerTupleExprContext(estate),
1913  &isNull);
1914 
1915  /* Get back to outer memory context */
1916  MemoryContextSwitchTo(oldcontext);
1917 
1918  /* Release all the junk we just created */
1919  FreeExecutorState(estate);
1920 
1921  if (isNull)
1922  {
1923  /* Treat a null result as non-proof ... but it's a tad fishy ... */
1924  elog(DEBUG2, "null predicate test result");
1925  return false;
1926  }
1927  return DatumGetBool(test_result);
1928 }
#define DEBUG2
Definition: elog.h:29
#define elog(elevel,...)
Definition: elog.h:224
ExprState * ExecInitExpr(Expr *node, PlanState *parent)
Definition: execExpr.c:127
EState * CreateExecutorState(void)
Definition: execUtils.c:88
void FreeExecutorState(EState *estate)
Definition: execUtils.c:189
#define GetPerTupleExprContext(estate)
Definition: executor.h:550
static Datum ExecEvalExprSwitchContext(ExprState *state, ExprContext *econtext, bool *isNull)
Definition: executor.h:348
Oid get_commutator(Oid opno)
Definition: lsyscache.c:1487
Expr * make_opclause(Oid opno, Oid opresulttype, bool opretset, Expr *leftop, Expr *rightop, Oid opcollid, Oid inputcollid)
Definition: makefuncs.c:612
void fix_opfuncids(Node *node)
Definition: nodeFuncs.c:1759
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:124
static bool DatumGetBool(Datum X)
Definition: postgres.h:90
static bool operator_same_subexprs_proof(Oid pred_op, Oid clause_op, bool refute_it)
Definition: predtest.c:1939
static Oid get_btree_test_op(Oid pred_op, Oid clause_op, bool refute_it)
Definition: predtest.c:2237
MemoryContext es_query_cxt
Definition: execnodes.h:665
Oid opno
Definition: primnodes.h:774
List * args
Definition: primnodes.h:792

References OpExpr::args, CreateExecutorState(), DatumGetBool(), DEBUG2, elog, equal(), EState::es_query_cxt, ExecEvalExprSwitchContext(), ExecInitExpr(), fix_opfuncids(), FreeExecutorState(), get_btree_test_op(), get_commutator(), GetPerTupleExprContext, InvalidOid, is_opclause(), IsA, linitial, list_length(), lsecond, make_opclause(), MemoryContextSwitchTo(), OidIsValid, op_strict(), operator_same_subexprs_proof(), and OpExpr::opno.

Referenced by predicate_implied_by_simple_clause(), and predicate_refuted_by_simple_clause().

◆ operator_same_subexprs_lookup()

static bool operator_same_subexprs_lookup ( Oid  pred_op,
Oid  clause_op,
bool  refute_it 
)
static

Definition at line 2212 of file predtest.c.

2213 {
2214  OprProofCacheEntry *cache_entry;
2215 
2216  cache_entry = lookup_proof_cache(pred_op, clause_op, refute_it);
2217  if (refute_it)
2218  return cache_entry->same_subexprs_refutes;
2219  else
2220  return cache_entry->same_subexprs_implies;
2221 }

References lookup_proof_cache(), OprProofCacheEntry::same_subexprs_implies, and OprProofCacheEntry::same_subexprs_refutes.

Referenced by operator_same_subexprs_proof().

◆ operator_same_subexprs_proof()

static bool operator_same_subexprs_proof ( Oid  pred_op,
Oid  clause_op,
bool  refute_it 
)
static

Definition at line 1939 of file predtest.c.

1940 {
1941  /*
1942  * A simple and general rule is that the predicate is proven if clause_op
1943  * and pred_op are the same, or refuted if they are each other's negators.
1944  * We need not check immutability since the pred_op is already known
1945  * immutable. (Actually, by this point we may have the commutator of a
1946  * known-immutable pred_op, but that should certainly be immutable too.
1947  * Likewise we don't worry whether the pred_op's negator is immutable.)
1948  *
1949  * Note: the "same" case won't get here if we actually had EXPR1 clause_op
1950  * EXPR2 and EXPR1 pred_op EXPR2, because the overall-expression-equality
1951  * test in predicate_implied_by_simple_clause would have caught it. But
1952  * we can see the same operator after having commuted the pred_op.
1953  */
1954  if (refute_it)
1955  {
1956  if (get_negator(pred_op) == clause_op)
1957  return true;
1958  }
1959  else
1960  {
1961  if (pred_op == clause_op)
1962  return true;
1963  }
1964 
1965  /*
1966  * Otherwise, see if we can determine the implication by finding the
1967  * operators' relationship via some btree opfamily.
1968  */
1969  return operator_same_subexprs_lookup(pred_op, clause_op, refute_it);
1970 }
static bool operator_same_subexprs_lookup(Oid pred_op, Oid clause_op, bool refute_it)
Definition: predtest.c:2212

References get_negator(), and operator_same_subexprs_lookup().

Referenced by operator_predicate_proof().

◆ predicate_classify()

static PredClass predicate_classify ( Node clause,
PredIterInfo  info 
)
static

Definition at line 826 of file predtest.c.

827 {
828  /* Caller should not pass us NULL, nor a RestrictInfo clause */
829  Assert(clause != NULL);
830  Assert(!IsA(clause, RestrictInfo));
831 
832  /*
833  * If we see a List, assume it's an implicit-AND list; this is the correct
834  * semantics for lists of RestrictInfo nodes.
835  */
836  if (IsA(clause, List))
837  {
838  info->startup_fn = list_startup_fn;
839  info->next_fn = list_next_fn;
840  info->cleanup_fn = list_cleanup_fn;
841  return CLASS_AND;
842  }
843 
844  /* Handle normal AND and OR boolean clauses */
845  if (is_andclause(clause))
846  {
848  info->next_fn = list_next_fn;
849  info->cleanup_fn = list_cleanup_fn;
850  return CLASS_AND;
851  }
852  if (is_orclause(clause))
853  {
855  info->next_fn = list_next_fn;
856  info->cleanup_fn = list_cleanup_fn;
857  return CLASS_OR;
858  }
859 
860  /* Handle ScalarArrayOpExpr */
861  if (IsA(clause, ScalarArrayOpExpr))
862  {
863  ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) clause;
864  Node *arraynode = (Node *) lsecond(saop->args);
865 
866  /*
867  * We can break this down into an AND or OR structure, but only if we
868  * know how to iterate through expressions for the array's elements.
869  * We can do that if the array operand is a non-null constant or a
870  * simple ArrayExpr.
871  */
872  if (arraynode && IsA(arraynode, Const) &&
873  !((Const *) arraynode)->constisnull)
874  {
875  ArrayType *arrayval;
876  int nelems;
877 
878  arrayval = DatumGetArrayTypeP(((Const *) arraynode)->constvalue);
879  nelems = ArrayGetNItems(ARR_NDIM(arrayval), ARR_DIMS(arrayval));
880  if (nelems <= MAX_SAOP_ARRAY_SIZE)
881  {
883  info->next_fn = arrayconst_next_fn;
885  return saop->useOr ? CLASS_OR : CLASS_AND;
886  }
887  }
888  else if (arraynode && IsA(arraynode, ArrayExpr) &&
889  !((ArrayExpr *) arraynode)->multidims &&
890  list_length(((ArrayExpr *) arraynode)->elements) <= MAX_SAOP_ARRAY_SIZE)
891  {
893  info->next_fn = arrayexpr_next_fn;
895  return saop->useOr ? CLASS_OR : CLASS_AND;
896  }
897  }
898 
899  /* None of the above, so it's an atom */
900  return CLASS_ATOM;
901 }
static bool is_andclause(const void *clause)
Definition: nodeFuncs.h:105
static bool is_orclause(const void *clause)
Definition: nodeFuncs.h:114
static Node * arrayconst_next_fn(PredIterInfo info)
Definition: predtest.c:1008
static Node * arrayexpr_next_fn(PredIterInfo info)
Definition: predtest.c:1069
static void arrayexpr_startup_fn(Node *clause, PredIterInfo info)
Definition: predtest.c:1042
static void boolexpr_startup_fn(Node *clause, PredIterInfo info)
Definition: predtest.c:938
static void arrayconst_startup_fn(Node *clause, PredIterInfo info)
Definition: predtest.c:959
#define MAX_SAOP_ARRAY_SIZE
Definition: predtest.c:40
static void list_cleanup_fn(PredIterInfo info)
Definition: predtest.c:928
static Node * list_next_fn(PredIterInfo info)
Definition: predtest.c:915
static void arrayconst_cleanup_fn(PredIterInfo info)
Definition: predtest.c:1021
static void list_startup_fn(Node *clause, PredIterInfo info)
Definition: predtest.c:908
static void arrayexpr_cleanup_fn(PredIterInfo info)
Definition: predtest.c:1081
void(* startup_fn)(Node *clause, PredIterInfo info)
Definition: predtest.c:65
void(* cleanup_fn)(PredIterInfo info)
Definition: predtest.c:69
Node *(* next_fn)(PredIterInfo info)
Definition: predtest.c:67

References ScalarArrayOpExpr::args, ARR_DIMS, ARR_NDIM, arrayconst_cleanup_fn(), arrayconst_next_fn(), arrayconst_startup_fn(), arrayexpr_cleanup_fn(), arrayexpr_next_fn(), arrayexpr_startup_fn(), ArrayGetNItems(), Assert(), boolexpr_startup_fn(), CLASS_AND, CLASS_ATOM, CLASS_OR, PredIterInfoData::cleanup_fn, DatumGetArrayTypeP, is_andclause(), is_orclause(), IsA, list_cleanup_fn(), list_length(), list_next_fn(), list_startup_fn(), lsecond, MAX_SAOP_ARRAY_SIZE, PredIterInfoData::next_fn, PredIterInfoData::startup_fn, and ScalarArrayOpExpr::useOr.

Referenced by predicate_implied_by_recurse(), and predicate_refuted_by_recurse().

◆ predicate_implied_by()

bool predicate_implied_by ( List predicate_list,
List clause_list,
bool  weak 
)

Definition at line 152 of file predtest.c.

154 {
155  Node *p,
156  *c;
157 
158  if (predicate_list == NIL)
159  return true; /* no predicate: implication is vacuous */
160  if (clause_list == NIL)
161  return false; /* no restriction: implication must fail */
162 
163  /*
164  * If either input is a single-element list, replace it with its lone
165  * member; this avoids one useless level of AND-recursion. We only need
166  * to worry about this at top level, since eval_const_expressions should
167  * have gotten rid of any trivial ANDs or ORs below that.
168  */
169  if (list_length(predicate_list) == 1)
170  p = (Node *) linitial(predicate_list);
171  else
172  p = (Node *) predicate_list;
173  if (list_length(clause_list) == 1)
174  c = (Node *) linitial(clause_list);
175  else
176  c = (Node *) clause_list;
177 
178  /* And away we go ... */
179  return predicate_implied_by_recurse(c, p, weak);
180 }
static bool predicate_implied_by_recurse(Node *clause, Node *predicate, bool weak)
Definition: predtest.c:290
char * c

References linitial, list_length(), NIL, and predicate_implied_by_recurse().

Referenced by add_predicate_to_index_quals(), build_paths_for_OR(), check_index_predicates(), choose_bitmap_and(), ConstraintImpliedByRelConstraint(), create_bitmap_scan_plan(), create_bitmap_subplan(), create_indexscan_plan(), infer_arbiter_indexes(), and test_predtest().

◆ predicate_implied_by_recurse()

static bool predicate_implied_by_recurse ( Node clause,
Node predicate,
bool  weak 
)
static

Definition at line 290 of file predtest.c.

292 {
293  PredIterInfoData clause_info;
294  PredIterInfoData pred_info;
295  PredClass pclass;
296  bool result;
297 
298  /* skip through RestrictInfo */
299  Assert(clause != NULL);
300  if (IsA(clause, RestrictInfo))
301  clause = (Node *) ((RestrictInfo *) clause)->clause;
302 
303  pclass = predicate_classify(predicate, &pred_info);
304 
305  switch (predicate_classify(clause, &clause_info))
306  {
307  case CLASS_AND:
308  switch (pclass)
309  {
310  case CLASS_AND:
311 
312  /*
313  * AND-clause => AND-clause if A implies each of B's items
314  */
315  result = true;
316  iterate_begin(pitem, predicate, pred_info)
317  {
318  if (!predicate_implied_by_recurse(clause, pitem,
319  weak))
320  {
321  result = false;
322  break;
323  }
324  }
325  iterate_end(pred_info);
326  return result;
327 
328  case CLASS_OR:
329 
330  /*
331  * AND-clause => OR-clause if A implies any of B's items
332  *
333  * Needed to handle (x AND y) => ((x AND y) OR z)
334  */
335  result = false;
336  iterate_begin(pitem, predicate, pred_info)
337  {
338  if (predicate_implied_by_recurse(clause, pitem,
339  weak))
340  {
341  result = true;
342  break;
343  }
344  }
345  iterate_end(pred_info);
346  if (result)
347  return result;
348 
349  /*
350  * Also check if any of A's items implies B
351  *
352  * Needed to handle ((x OR y) AND z) => (x OR y)
353  */
354  iterate_begin(citem, clause, clause_info)
355  {
356  if (predicate_implied_by_recurse(citem, predicate,
357  weak))
358  {
359  result = true;
360  break;
361  }
362  }
363  iterate_end(clause_info);
364  return result;
365 
366  case CLASS_ATOM:
367 
368  /*
369  * AND-clause => atom if any of A's items implies B
370  */
371  result = false;
372  iterate_begin(citem, clause, clause_info)
373  {
374  if (predicate_implied_by_recurse(citem, predicate,
375  weak))
376  {
377  result = true;
378  break;
379  }
380  }
381  iterate_end(clause_info);
382  return result;
383  }
384  break;
385 
386  case CLASS_OR:
387  switch (pclass)
388  {
389  case CLASS_OR:
390 
391  /*
392  * OR-clause => OR-clause if each of A's items implies any
393  * of B's items. Messy but can't do it any more simply.
394  */
395  result = true;
396  iterate_begin(citem, clause, clause_info)
397  {
398  bool presult = false;
399 
400  iterate_begin(pitem, predicate, pred_info)
401  {
402  if (predicate_implied_by_recurse(citem, pitem,
403  weak))
404  {
405  presult = true;
406  break;
407  }
408  }
409  iterate_end(pred_info);
410  if (!presult)
411  {
412  result = false; /* doesn't imply any of B's */
413  break;
414  }
415  }
416  iterate_end(clause_info);
417  return result;
418 
419  case CLASS_AND:
420  case CLASS_ATOM:
421 
422  /*
423  * OR-clause => AND-clause if each of A's items implies B
424  *
425  * OR-clause => atom if each of A's items implies B
426  */
427  result = true;
428  iterate_begin(citem, clause, clause_info)
429  {
430  if (!predicate_implied_by_recurse(citem, predicate,
431  weak))
432  {
433  result = false;
434  break;
435  }
436  }
437  iterate_end(clause_info);
438  return result;
439  }
440  break;
441 
442  case CLASS_ATOM:
443  switch (pclass)
444  {
445  case CLASS_AND:
446 
447  /*
448  * atom => AND-clause if A implies each of B's items
449  */
450  result = true;
451  iterate_begin(pitem, predicate, pred_info)
452  {
453  if (!predicate_implied_by_recurse(clause, pitem,
454  weak))
455  {
456  result = false;
457  break;
458  }
459  }
460  iterate_end(pred_info);
461  return result;
462 
463  case CLASS_OR:
464 
465  /*
466  * atom => OR-clause if A implies any of B's items
467  */
468  result = false;
469  iterate_begin(pitem, predicate, pred_info)
470  {
471  if (predicate_implied_by_recurse(clause, pitem,
472  weak))
473  {
474  result = true;
475  break;
476  }
477  }
478  iterate_end(pred_info);
479  return result;
480 
481  case CLASS_ATOM:
482 
483  /*
484  * atom => atom is the base case
485  */
486  return
488  clause,
489  weak);
490  }
491  break;
492  }
493 
494  /* can't get here */
495  elog(ERROR, "predicate_classify returned a bogus value");
496  return false;
497 }
#define ERROR
Definition: elog.h:39
#define iterate_end(info)
Definition: predtest.c:78
static bool predicate_implied_by_simple_clause(Expr *predicate, Node *clause, bool weak)
Definition: predtest.c:1124
static PredClass predicate_classify(Node *clause, PredIterInfo info)
Definition: predtest.c:826
#define iterate_begin(item, clause, info)
Definition: predtest.c:72

References Assert(), CLASS_AND, CLASS_ATOM, CLASS_OR, elog, ERROR, IsA, iterate_begin, iterate_end, predicate_classify(), and predicate_implied_by_simple_clause().

Referenced by predicate_implied_by(), and predicate_refuted_by_recurse().

◆ predicate_implied_by_simple_clause()

static bool predicate_implied_by_simple_clause ( Expr predicate,
Node clause,
bool  weak 
)
static

Definition at line 1124 of file predtest.c.

1126 {
1127  /* Allow interrupting long proof attempts */
1129 
1130  /* First try the equal() test */
1131  if (equal((Node *) predicate, clause))
1132  return true;
1133 
1134  /* Next see if clause is boolean equality to a constant */
1135  if (is_opclause(clause) &&
1136  ((OpExpr *) clause)->opno == BooleanEqualOperator)
1137  {
1138  OpExpr *op = (OpExpr *) clause;
1139  Node *rightop;
1140 
1141  Assert(list_length(op->args) == 2);
1142  rightop = lsecond(op->args);
1143  /* We might never see a null Const here, but better check anyway */
1144  if (rightop && IsA(rightop, Const) &&
1145  !((Const *) rightop)->constisnull)
1146  {
1147  Node *leftop = linitial(op->args);
1148 
1149  if (DatumGetBool(((Const *) rightop)->constvalue))
1150  {
1151  /* X = true implies X */
1152  if (equal(predicate, leftop))
1153  return true;
1154  }
1155  else
1156  {
1157  /* X = false implies NOT X */
1158  if (is_notclause(predicate) &&
1159  equal(get_notclausearg(predicate), leftop))
1160  return true;
1161  }
1162  }
1163  }
1164 
1165  /*
1166  * We could likewise check whether the predicate is boolean equality to a
1167  * constant; but there are no known use-cases for that at the moment,
1168  * assuming that the predicate has been through constant-folding.
1169  */
1170 
1171  /* Next try the IS NOT NULL case */
1172  if (!weak &&
1173  predicate && IsA(predicate, NullTest))
1174  {
1175  NullTest *ntest = (NullTest *) predicate;
1176 
1177  /* row IS NOT NULL does not act in the simple way we have in mind */
1178  if (ntest->nulltesttype == IS_NOT_NULL &&
1179  !ntest->argisrow)
1180  {
1181  /* strictness of clause for foo implies foo IS NOT NULL */
1182  if (clause_is_strict_for(clause, (Node *) ntest->arg, true))
1183  return true;
1184  }
1185  return false; /* we can't succeed below... */
1186  }
1187 
1188  /* Else try operator-related knowledge */
1189  return operator_predicate_proof(predicate, clause, false, weak);
1190 }
#define CHECK_FOR_INTERRUPTS()
Definition: miscadmin.h:122
static Expr * get_notclausearg(const void *notclause)
Definition: nodeFuncs.h:132
static bool is_notclause(const void *clause)
Definition: nodeFuncs.h:123
static bool operator_predicate_proof(Expr *predicate, Node *clause, bool refute_it, bool weak)
Definition: predtest.c:1686
@ IS_NOT_NULL
Definition: primnodes.h:1715
NullTestType nulltesttype
Definition: primnodes.h:1722
Expr * arg
Definition: primnodes.h:1721

References NullTest::arg, OpExpr::args, Assert(), CHECK_FOR_INTERRUPTS, clause_is_strict_for(), DatumGetBool(), equal(), get_notclausearg(), IS_NOT_NULL, is_notclause(), is_opclause(), IsA, linitial, list_length(), lsecond, NullTest::nulltesttype, and operator_predicate_proof().

Referenced by predicate_implied_by_recurse().

◆ predicate_refuted_by()

bool predicate_refuted_by ( List predicate_list,
List clause_list,
bool  weak 
)

Definition at line 222 of file predtest.c.

224 {
225  Node *p,
226  *c;
227 
228  if (predicate_list == NIL)
229  return false; /* no predicate: no refutation is possible */
230  if (clause_list == NIL)
231  return false; /* no restriction: refutation must fail */
232 
233  /*
234  * If either input is a single-element list, replace it with its lone
235  * member; this avoids one useless level of AND-recursion. We only need
236  * to worry about this at top level, since eval_const_expressions should
237  * have gotten rid of any trivial ANDs or ORs below that.
238  */
239  if (list_length(predicate_list) == 1)
240  p = (Node *) linitial(predicate_list);
241  else
242  p = (Node *) predicate_list;
243  if (list_length(clause_list) == 1)
244  c = (Node *) linitial(clause_list);
245  else
246  c = (Node *) clause_list;
247 
248  /* And away we go ... */
249  return predicate_refuted_by_recurse(c, p, weak);
250 }
static bool predicate_refuted_by_recurse(Node *clause, Node *predicate, bool weak)
Definition: predtest.c:531

References linitial, list_length(), NIL, and predicate_refuted_by_recurse().

Referenced by gen_partprune_steps_internal(), relation_excluded_by_constraints(), and test_predtest().

◆ predicate_refuted_by_recurse()

static bool predicate_refuted_by_recurse ( Node clause,
Node predicate,
bool  weak 
)
static

Definition at line 531 of file predtest.c.

533 {
534  PredIterInfoData clause_info;
535  PredIterInfoData pred_info;
536  PredClass pclass;
537  Node *not_arg;
538  bool result;
539 
540  /* skip through RestrictInfo */
541  Assert(clause != NULL);
542  if (IsA(clause, RestrictInfo))
543  clause = (Node *) ((RestrictInfo *) clause)->clause;
544 
545  pclass = predicate_classify(predicate, &pred_info);
546 
547  switch (predicate_classify(clause, &clause_info))
548  {
549  case CLASS_AND:
550  switch (pclass)
551  {
552  case CLASS_AND:
553 
554  /*
555  * AND-clause R=> AND-clause if A refutes any of B's items
556  *
557  * Needed to handle (x AND y) R=> ((!x OR !y) AND z)
558  */
559  result = false;
560  iterate_begin(pitem, predicate, pred_info)
561  {
562  if (predicate_refuted_by_recurse(clause, pitem,
563  weak))
564  {
565  result = true;
566  break;
567  }
568  }
569  iterate_end(pred_info);
570  if (result)
571  return result;
572 
573  /*
574  * Also check if any of A's items refutes B
575  *
576  * Needed to handle ((x OR y) AND z) R=> (!x AND !y)
577  */
578  iterate_begin(citem, clause, clause_info)
579  {
580  if (predicate_refuted_by_recurse(citem, predicate,
581  weak))
582  {
583  result = true;
584  break;
585  }
586  }
587  iterate_end(clause_info);
588  return result;
589 
590  case CLASS_OR:
591 
592  /*
593  * AND-clause R=> OR-clause if A refutes each of B's items
594  */
595  result = true;
596  iterate_begin(pitem, predicate, pred_info)
597  {
598  if (!predicate_refuted_by_recurse(clause, pitem,
599  weak))
600  {
601  result = false;
602  break;
603  }
604  }
605  iterate_end(pred_info);
606  return result;
607 
608  case CLASS_ATOM:
609 
610  /*
611  * If B is a NOT-type clause, A R=> B if A => B's arg
612  *
613  * Since, for either type of refutation, we are starting
614  * with the premise that A is true, we can use a strong
615  * implication test in all cases. That proves B's arg is
616  * true, which is more than we need for weak refutation if
617  * B is a simple NOT, but it allows not worrying about
618  * exactly which kind of negation clause we have.
619  */
620  not_arg = extract_not_arg(predicate);
621  if (not_arg &&
622  predicate_implied_by_recurse(clause, not_arg,
623  false))
624  return true;
625 
626  /*
627  * AND-clause R=> atom if any of A's items refutes B
628  */
629  result = false;
630  iterate_begin(citem, clause, clause_info)
631  {
632  if (predicate_refuted_by_recurse(citem, predicate,
633  weak))
634  {
635  result = true;
636  break;
637  }
638  }
639  iterate_end(clause_info);
640  return result;
641  }
642  break;
643 
644  case CLASS_OR:
645  switch (pclass)
646  {
647  case CLASS_OR:
648 
649  /*
650  * OR-clause R=> OR-clause if A refutes each of B's items
651  */
652  result = true;
653  iterate_begin(pitem, predicate, pred_info)
654  {
655  if (!predicate_refuted_by_recurse(clause, pitem,
656  weak))
657  {
658  result = false;
659  break;
660  }
661  }
662  iterate_end(pred_info);
663  return result;
664 
665  case CLASS_AND:
666 
667  /*
668  * OR-clause R=> AND-clause if each of A's items refutes
669  * any of B's items.
670  */
671  result = true;
672  iterate_begin(citem, clause, clause_info)
673  {
674  bool presult = false;
675 
676  iterate_begin(pitem, predicate, pred_info)
677  {
678  if (predicate_refuted_by_recurse(citem, pitem,
679  weak))
680  {
681  presult = true;
682  break;
683  }
684  }
685  iterate_end(pred_info);
686  if (!presult)
687  {
688  result = false; /* citem refutes nothing */
689  break;
690  }
691  }
692  iterate_end(clause_info);
693  return result;
694 
695  case CLASS_ATOM:
696 
697  /*
698  * If B is a NOT-type clause, A R=> B if A => B's arg
699  *
700  * Same logic as for the AND-clause case above.
701  */
702  not_arg = extract_not_arg(predicate);
703  if (not_arg &&
704  predicate_implied_by_recurse(clause, not_arg,
705  false))
706  return true;
707 
708  /*
709  * OR-clause R=> atom if each of A's items refutes B
710  */
711  result = true;
712  iterate_begin(citem, clause, clause_info)
713  {
714  if (!predicate_refuted_by_recurse(citem, predicate,
715  weak))
716  {
717  result = false;
718  break;
719  }
720  }
721  iterate_end(clause_info);
722  return result;
723  }
724  break;
725 
726  case CLASS_ATOM:
727 
728  /*
729  * If A is a strong NOT-clause, A R=> B if B => A's arg
730  *
731  * Since A is strong, we may assume A's arg is false (not just
732  * not-true). If B weakly implies A's arg, then B can be neither
733  * true nor null, so that strong refutation is proven. If B
734  * strongly implies A's arg, then B cannot be true, so that weak
735  * refutation is proven.
736  */
737  not_arg = extract_strong_not_arg(clause);
738  if (not_arg &&
739  predicate_implied_by_recurse(predicate, not_arg,
740  !weak))
741  return true;
742 
743  switch (pclass)
744  {
745  case CLASS_AND:
746 
747  /*
748  * atom R=> AND-clause if A refutes any of B's items
749  */
750  result = false;
751  iterate_begin(pitem, predicate, pred_info)
752  {
753  if (predicate_refuted_by_recurse(clause, pitem,
754  weak))
755  {
756  result = true;
757  break;
758  }
759  }
760  iterate_end(pred_info);
761  return result;
762 
763  case CLASS_OR:
764 
765  /*
766  * atom R=> OR-clause if A refutes each of B's items
767  */
768  result = true;
769  iterate_begin(pitem, predicate, pred_info)
770  {
771  if (!predicate_refuted_by_recurse(clause, pitem,
772  weak))
773  {
774  result = false;
775  break;
776  }
777  }
778  iterate_end(pred_info);
779  return result;
780 
781  case CLASS_ATOM:
782 
783  /*
784  * If B is a NOT-type clause, A R=> B if A => B's arg
785  *
786  * Same logic as for the AND-clause case above.
787  */
788  not_arg = extract_not_arg(predicate);
789  if (not_arg &&
790  predicate_implied_by_recurse(clause, not_arg,
791  false))
792  return true;
793 
794  /*
795  * atom R=> atom is the base case
796  */
797  return
799  clause,
800  weak);
801  }
802  break;
803  }
804 
805  /* can't get here */
806  elog(ERROR, "predicate_classify returned a bogus value");
807  return false;
808 }
static bool predicate_refuted_by_simple_clause(Expr *predicate, Node *clause, bool weak)
Definition: predtest.c:1223
static Node * extract_strong_not_arg(Node *clause)
Definition: predtest.c:1321
static Node * extract_not_arg(Node *clause)
Definition: predtest.c:1293

References Assert(), CLASS_AND, CLASS_ATOM, CLASS_OR, elog, ERROR, extract_not_arg(), extract_strong_not_arg(), IsA, iterate_begin, iterate_end, predicate_classify(), predicate_implied_by_recurse(), and predicate_refuted_by_simple_clause().

Referenced by predicate_refuted_by().

◆ predicate_refuted_by_simple_clause()

static bool predicate_refuted_by_simple_clause ( Expr predicate,
Node clause,
bool  weak 
)
static

Definition at line 1223 of file predtest.c.

1225 {
1226  /* Allow interrupting long proof attempts */
1228 
1229  /* A simple clause can't refute itself */
1230  /* Worth checking because of relation_excluded_by_constraints() */
1231  if ((Node *) predicate == clause)
1232  return false;
1233 
1234  /* Try the predicate-IS-NULL case */
1235  if (predicate && IsA(predicate, NullTest) &&
1236  ((NullTest *) predicate)->nulltesttype == IS_NULL)
1237  {
1238  Expr *isnullarg = ((NullTest *) predicate)->arg;
1239 
1240  /* row IS NULL does not act in the simple way we have in mind */
1241  if (((NullTest *) predicate)->argisrow)
1242  return false;
1243 
1244  /* strictness of clause for foo refutes foo IS NULL */
1245  if (clause_is_strict_for(clause, (Node *) isnullarg, true))
1246  return true;
1247 
1248  /* foo IS NOT NULL refutes foo IS NULL */
1249  if (clause && IsA(clause, NullTest) &&
1250  ((NullTest *) clause)->nulltesttype == IS_NOT_NULL &&
1251  !((NullTest *) clause)->argisrow &&
1252  equal(((NullTest *) clause)->arg, isnullarg))
1253  return true;
1254 
1255  return false; /* we can't succeed below... */
1256  }
1257 
1258  /* Try the clause-IS-NULL case */
1259  if (clause && IsA(clause, NullTest) &&
1260  ((NullTest *) clause)->nulltesttype == IS_NULL)
1261  {
1262  Expr *isnullarg = ((NullTest *) clause)->arg;
1263 
1264  /* row IS NULL does not act in the simple way we have in mind */
1265  if (((NullTest *) clause)->argisrow)
1266  return false;
1267 
1268  /* foo IS NULL refutes foo IS NOT NULL */
1269  if (predicate && IsA(predicate, NullTest) &&
1270  ((NullTest *) predicate)->nulltesttype == IS_NOT_NULL &&
1271  !((NullTest *) predicate)->argisrow &&
1272  equal(((NullTest *) predicate)->arg, isnullarg))
1273  return true;
1274 
1275  /* foo IS NULL weakly refutes any predicate that is strict for foo */
1276  if (weak &&
1277  clause_is_strict_for((Node *) predicate, (Node *) isnullarg, true))
1278  return true;
1279 
1280  return false; /* we can't succeed below... */
1281  }
1282 
1283  /* Else try operator-related knowledge */
1284  return operator_predicate_proof(predicate, clause, true, weak);
1285 }
@ IS_NULL
Definition: primnodes.h:1715

References arg, CHECK_FOR_INTERRUPTS, clause_is_strict_for(), equal(), IS_NOT_NULL, IS_NULL, IsA, and operator_predicate_proof().

Referenced by predicate_refuted_by_recurse().

Variable Documentation

◆ BT_implic_table

const StrategyNumber BT_implic_table[6][6]
static
Initial value:
= {
}
#define BTLT
Definition: predtest.c:1569
#define BTGE
Definition: predtest.c:1572
#define none
Definition: predtest.c:1577
#define BTGT
Definition: predtest.c:1573
#define BTLE
Definition: predtest.c:1570
#define BTEQ
Definition: predtest.c:1571

Definition at line 1605 of file predtest.c.

Referenced by lookup_proof_cache().

◆ BT_implies_table

const bool BT_implies_table[6][6]
static
Initial value:
= {
{true, true, none, none, none, true},
{none, true, none, none, none, none},
{none, true, true, true, none, none},
{none, none, none, true, none, none},
{none, none, none, true, true, true},
{none, none, none, none, none, true}
}

Definition at line 1579 of file predtest.c.

Referenced by lookup_proof_cache().

◆ BT_refute_table

const StrategyNumber BT_refute_table[6][6]
static
Initial value:

Definition at line 1618 of file predtest.c.

Referenced by lookup_proof_cache().

◆ BT_refutes_table

const bool BT_refutes_table[6][6]
static
Initial value:
= {
{none, none, true, true, true, none},
{none, none, none, none, true, none},
{true, none, none, none, true, true},
{true, none, none, none, none, none},
{true, true, true, none, none, none},
{none, none, true, none, none, none}
}

Definition at line 1592 of file predtest.c.

Referenced by lookup_proof_cache().

◆ OprProofCacheHash

HTAB* OprProofCacheHash = NULL
static

Definition at line 2000 of file predtest.c.

Referenced by InvalidateOprProofCacheCallBack(), and lookup_proof_cache().