*
* nodeHashjoin.cpp
* Routines to handle hash join nodes
*
* Portions Copyright (c) 2020 Huawei Technologies Co.,Ltd.
* Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/gausskernel/runtime/executor/nodeHashjoin.cpp
*
* -------------------------------------------------------------------------
*/
#include "postgres.h"
#include "knl/knl_variable.h"
#include "executor/executor.h"
#include "executor/exec/execStream.h"
#include "executor/hashjoin.h"
#include "executor/node/nodeHash.h"
#include "executor/node/nodeHashjoin.h"
#include "miscadmin.h"
#include "utils/anls_opt.h"
#include "utils/memutils.h"
* States of the ExecHashJoin state machine
*/
#define HJ_BUILD_HASHTABLE 1
#define HJ_NEED_NEW_OUTER 2
#define HJ_SCAN_BUCKET 3
#define HJ_FILL_OUTER_TUPLE 4
#define HJ_FILL_INNER_TUPLES 5
#define HJ_NEED_NEW_BATCH 6
#define HJ_FILL_OUTER(hjstate) ((hjstate)->hj_NullInnerTupleSlot != NULL)
#define HJ_FILL_INNER(hjstate) ((hjstate)->hj_NullOuterTupleSlot != NULL)
static TupleTableSlot* ExecHashJoin(PlanState* state);
static TupleTableSlot* ExecHashJoinOuterGetTuple(PlanState* outerNode, HashJoinState* hjstate, uint32* hashvalue);
static TupleTableSlot* ExecHashJoinGetSavedTuple(
HashJoinState* hjstate, BufFile* file, uint32* hashvalue, TupleTableSlot* tupleSlot);
static bool ExecHashJoinNewBatch(HashJoinState* hjstate);
* ExecHashJoin
*
* This function implements the Hybrid Hashjoin algorithm.
*
* Note: the relation we build hash table on is the "inner"
* the other one is "outer".
* ----------------------------------------------------------------
*/
static TupleTableSlot* ExecHashJoin(PlanState* state)
{
HashJoinState* node = castNode(HashJoinState, state);
PlanState* outerNode = NULL;
HashState* hashNode = NULL;
List* joinqual = NIL;
List* otherqual = NIL;
ExprContext* econtext = NULL;
ExprDoneCond isDone;
HashJoinTable hashtable;
TupleTableSlot* outerTupleSlot = NULL;
uint32 hashvalue;
int batchno;
MemoryContext oldcxt = NULL;
JoinType jointype;
* get information from HashJoin node
*/
joinqual = node->js.joinqual;
otherqual = node->js.ps.qual;
hashNode = (HashState*)innerPlanState(node);
outerNode = outerPlanState(node);
hashtable = node->hj_HashTable;
econtext = node->js.ps.ps_ExprContext;
jointype = node->js.jointype;
* Check to see if we're still projecting out tuples from a previous join
* tuple (because there is a function-returning-set in the projection
* expressions). If so, try to project another one.
*/
if (node->js.ps.ps_vec_TupFromTlist) {
TupleTableSlot* result = NULL;
result = ExecProject(node->js.ps.ps_ProjInfo, &isDone);
if (isDone == ExprMultipleResult)
return result;
node->js.ps.ps_vec_TupFromTlist = false;
}
* Reset per-tuple memory context to free any expression evaluation
* storage allocated in the previous tuple cycle. Note this can't happen
* until we're done projecting out tuples from a join tuple.
*/
ResetExprContext(econtext);
* run the hash join state machine
*/
for (;;) {
* It's possible to iterate this loop many times before returning a
* tuple, in some pathological cases such as needing to move much of
* the current batch to a later batch. So let's check for interrupts
* each time through.
*/
CHECK_FOR_INTERRUPTS();
switch (node->hj_JoinState) {
case HJ_BUILD_HASHTABLE: {
* First time through: build hash table for inner relation.
*/
Assert(hashtable == NULL);
#ifdef USE_SPQ
if (IS_SPQ_RUNNING && node->prefetch_inner) {
node->hj_FirstOuterTupleSlot = NULL;
goto CREATE_HASH_TABLE;
}
#endif
* If the outer relation is completely empty, and it's not
* right/full join, we can quit without building the hash
* table. However, for an inner join it is only a win to
* check this when the outer relation's startup cost is less
* than the projected cost of building the hash table.
* Otherwise it's best to build the hash table first and see
* if the inner relation is empty. (When it's a left join, we
* should always make this check, since we aren't going to be
* able to skip the join on the strength of an empty inner
* relation anyway.)
*
* If we are rescanning the join, we make use of information
* gained on the previous scan: don't bother to try the
* prefetch if the previous scan found the outer relation
* nonempty. This is not 100% reliable since with new
* parameters the outer relation might yield different
* results, but it's a good heuristic.
*
* The only way to make the check is to try to fetch a tuple
* from the outer plan node. If we succeed, we have to stash
* it away for later consumption by ExecHashJoinOuterGetTuple.
*/
if (HJ_FILL_INNER(node)) {
node->hj_FirstOuterTupleSlot = NULL;
} else if ((HJ_FILL_OUTER(node) || (outerNode->plan->startup_cost < hashNode->ps.plan->total_cost &&
!node->hj_OuterNotEmpty)) &&
!node->hj_streamBothSides) {
node->hj_FirstOuterTupleSlot = ExecProcNode(outerNode);
if (TupIsNull(node->hj_FirstOuterTupleSlot)) {
node->hj_OuterNotEmpty = false;
* If the outer relation is completely empty, and it's not right/full join,
* we should deinit the consumer in right tree earlier.
* It should be noticed that we can not do early deinit
* within predpush.
*/
if (((PlanState*)node) != NULL && !CheckParamWalker((PlanState*)node)) {
ExecEarlyDeinitConsumer((PlanState*)node);
}
ExecEarlyFree((PlanState*)node);
EARLY_FREE_LOG(elog(LOG, "Early Free: HashJoin early return NULL"
" at node %d, memory used %d MB.", (node->js.ps.plan)->plan_node_id,
getSessionMemoryUsageMB()));
return NULL;
} else
node->hj_OuterNotEmpty = true;
} else
node->hj_FirstOuterTupleSlot = NULL;
#ifdef USE_SPQ
CREATE_HASH_TABLE:
bool keepNulls = (IS_SPQ_RUNNING) ?
(HJ_FILL_INNER(node) || hashNode->hs_keepnull):
(HJ_FILL_INNER(node) || node->js.nulleqqual != NIL);
#endif
* create the hash table, sometimes we should keep nulls
*/
if (hashNode->ps.nodeContext) {
oldcxt = MemoryContextSwitchTo(hashNode->ps.nodeContext);
}
#ifdef USE_SPQ
hashtable = ExecHashTableCreate((Hash*)hashNode->ps.plan, node->hj_HashOperators,
keepNulls, node->hj_hashCollations);
#else
hashtable = ExecHashTableCreate((Hash*)hashNode->ps.plan, node->hj_HashOperators,
HJ_FILL_INNER(node) || node->js.nulleqqual != NIL, node->hj_hashCollations);
#endif
if (oldcxt) {
MemoryContextSwitchTo(oldcxt);
}
node->hj_HashTable = hashtable;
#ifdef USE_SPQ
if (IS_SPQ_RUNNING) {
hashNode->hs_quit_if_hashkeys_null = (node->js.jointype == JOIN_LASJ_NOTIN);
}
#endif
* execute the Hash node, to build the hash table
*/
WaitState oldStatus = pgstat_report_waitstatus(STATE_EXEC_HASHJOIN_BUILD_HASH);
hashNode->hashtable = hashtable;
hashNode->ps.hbktScanSlot.currSlot = node->js.ps.hbktScanSlot.currSlot;
(void)MultiExecProcNode((PlanState*)hashNode);
(void)pgstat_report_waitstatus(oldStatus);
ExecEarlyFree((PlanState*)hashNode);
EARLY_FREE_LOG(elog(LOG, "Early Free: Hash Table for HashJoin"
" is built at node %d, memory used %d MB.",
(node->js.ps.plan)->plan_node_id, getSessionMemoryUsageMB()));
#ifdef USE_SPQ
if (IS_SPQ_RUNNING && node->js.jointype == JOIN_LASJ_NOTIN && hashNode->hs_hashkeys_null)
return NULL;
#endif
* If the inner relation is completely empty, and we're not
* doing a left outer join, we can quit without scanning the
* outer relation.
*/
if (hashtable->totalTuples == 0 && !HJ_FILL_OUTER(node)) {
* When hash table size is zero, no need to fetch left tree any more and
* should deinit the consumer in left tree earlier.
* It should be noticed that we can not do early deinit
* within predpush.
*/
if (((PlanState*)node) != NULL && !CheckParamWalker((PlanState*)node)) {
ExecEarlyDeinitConsumer((PlanState*)node);
}
return NULL;
}
#ifdef USE_SPQ
if (IS_SPQ_RUNNING) {
node->hj_InnerEmpty = (hashtable->totalTuples == 0);
}
#endif
* need to remember whether nbatch has increased since we
* began scanning the outer relation
*/
hashtable->nbatch_outstart = hashtable->nbatch;
* Reset OuterNotEmpty for scan. (It's OK if we fetched a
* tuple above, because ExecHashJoinOuterGetTuple will
* immediately set it again.)
*/
node->hj_OuterNotEmpty = false;
node->hj_JoinState = HJ_NEED_NEW_OUTER;
}
case HJ_NEED_NEW_OUTER:
* We don't have an outer tuple, try to get the next one
*/
outerTupleSlot = ExecHashJoinOuterGetTuple(outerNode, node, &hashvalue);
if (TupIsNull(outerTupleSlot)) {
if (HJ_FILL_INNER(node)) {
ExecPrepHashTableForUnmatched(node);
node->hj_JoinState = HJ_FILL_INNER_TUPLES;
} else
node->hj_JoinState = HJ_NEED_NEW_BATCH;
continue;
}
econtext->ecxt_outertuple = outerTupleSlot;
node->hj_MatchedOuter = false;
* Find the corresponding bucket for this tuple in the main
* hash table or skew hash table.
*/
node->hj_CurHashValue = hashvalue;
ExecHashGetBucketAndBatch(hashtable, hashvalue, &node->hj_CurBucketNo, &batchno);
node->hj_CurSkewBucketNo = ExecHashGetSkewBucket(hashtable, hashvalue);
node->hj_CurTuple = NULL;
* The tuple might not belong to the current batch (where
* "current batch" includes the skew buckets if any).
*/
if (batchno != hashtable->curbatch && node->hj_CurSkewBucketNo == INVALID_SKEW_BUCKET_NO) {
* Need to postpone this outer tuple to a later batch.
* Save it in the corresponding outer-batch file.
*/
Assert(batchno > hashtable->curbatch);
MinimalTuple tuple = ExecFetchSlotMinimalTuple(outerTupleSlot);
ExecHashJoinSaveTuple(tuple, hashvalue, &hashtable->outerBatchFile[batchno]);
*hashtable->spill_size += sizeof(uint32) + tuple->t_len;
pgstat_increase_session_spill_size(sizeof(uint32) + tuple->t_len);
continue;
}
node->hj_JoinState = HJ_SCAN_BUCKET;
if (jointype == JOIN_RIGHT_ANTI || jointype == JOIN_RIGHT_SEMI)
node->hj_PreTuple = NULL;
case HJ_SCAN_BUCKET:
#ifdef USE_SPQ
if (IS_SPQ_RUNNING && node->js.jointype == JOIN_LASJ_NOTIN && !node->hj_InnerEmpty &&
IsJoinExprNull(node->hj_OuterHashKeys, econtext)) {
node->hj_MatchedOuter = true;
node->hj_JoinState = HJ_NEED_NEW_OUTER;
continue;
}
#endif
* Scan the selected hash bucket for matches to current outer
*/
if (!ExecScanHashBucket(node, econtext)) {
node->hj_JoinState = HJ_FILL_OUTER_TUPLE;
continue;
}
* We've got a match, but still need to test non-hashed quals.
* ExecScanHashBucket already set up all the state needed to
* call ExecQual.
*
* If we pass the qual, then save state for next call and have
* ExecProject form the projection, store it in the tuple
* table, and return the slot.
*
* Only the joinquals determine tuple match status, but all
* quals must pass to actually return the tuple.
*/
if (joinqual == NIL || ExecQual(joinqual, econtext, false)) {
node->hj_MatchedOuter = true;
* for right-anti join: skip and delete the matched tuple;
* for right-semi join: return and delete the matched tuple;
* for right-anti-full join: skip and delete the matched tuple;
*/
if (jointype == JOIN_RIGHT_ANTI || jointype == JOIN_RIGHT_SEMI ||
jointype == JOIN_RIGHT_ANTI_FULL) {
if (node->hj_PreTuple)
node->hj_PreTuple->next = node->hj_CurTuple->next;
else if (node->hj_CurSkewBucketNo != INVALID_SKEW_BUCKET_NO)
hashtable->skewBucket[node->hj_CurSkewBucketNo]->tuples = node->hj_CurTuple->next;
else
hashtable->buckets[node->hj_CurBucketNo] = node->hj_CurTuple->next;
if (jointype == JOIN_RIGHT_ANTI || jointype == JOIN_RIGHT_ANTI_FULL)
continue;
} else {
HeapTupleHeaderSetMatch(HJTUPLE_MINTUPLE(node->hj_CurTuple));
#ifdef USE_SPQ
if (jointype == JOIN_ANTI || jointype == JOIN_LEFT_ANTI_FULL ||
(IS_SPQ_RUNNING && jointype == JOIN_LASJ_NOTIN)) {
#else
if (jointype == JOIN_ANTI || jointype == JOIN_LEFT_ANTI_FULL) {
#endif
node->hj_JoinState = HJ_NEED_NEW_OUTER;
continue;
}
if (node->js.single_match) {
node->hj_JoinState = HJ_NEED_NEW_OUTER;
}
}
if (otherqual == NIL || ExecQual(otherqual, econtext, false)) {
TupleTableSlot* result = NULL;
result = ExecProject(node->js.ps.ps_ProjInfo, &isDone);
if (isDone != ExprEndResult) {
node->js.ps.ps_vec_TupFromTlist = (isDone == ExprMultipleResult);
return result;
}
} else
InstrCountFiltered2(node, 1);
} else {
InstrCountFiltered1(node, 1);
if (jointype == JOIN_RIGHT_ANTI || jointype == JOIN_RIGHT_SEMI)
node->hj_PreTuple = node->hj_CurTuple;
}
break;
case HJ_FILL_OUTER_TUPLE:
* The current outer tuple has run out of matches, so check
* whether to emit a dummy outer-join tuple. Whether we emit
* one or not, the next state is NEED_NEW_OUTER.
*/
node->hj_JoinState = HJ_NEED_NEW_OUTER;
if (!node->hj_MatchedOuter && HJ_FILL_OUTER(node)) {
* Generate a fake join tuple with nulls for the inner
* tuple, and return it if it passes the non-join quals.
*/
econtext->ecxt_innertuple = node->hj_NullInnerTupleSlot;
if (otherqual == NIL || ExecQual(otherqual, econtext, false)) {
TupleTableSlot* result = NULL;
result = ExecProject(node->js.ps.ps_ProjInfo, &isDone);
if (isDone != ExprEndResult) {
node->js.ps.ps_vec_TupFromTlist = (isDone == ExprMultipleResult);
return result;
}
} else
InstrCountFiltered2(node, 1);
}
break;
case HJ_FILL_INNER_TUPLES:
* We have finished a batch, but we are doing right/full/rightAnti join,
* so any unmatched inner tuples in the hashtable have to be
* emitted before we continue to the next batch.
*/
if (!ExecScanHashTableForUnmatched(node, econtext)) {
node->hj_JoinState = HJ_NEED_NEW_BATCH;
continue;
}
* Generate a fake join tuple with nulls for the outer tuple,
* and return it if it passes the non-join quals.
*/
econtext->ecxt_outertuple = node->hj_NullOuterTupleSlot;
if (otherqual == NIL || ExecQual(otherqual, econtext, false)) {
TupleTableSlot* result = NULL;
result = ExecProject(node->js.ps.ps_ProjInfo, &isDone);
if (isDone != ExprEndResult) {
node->js.ps.ps_vec_TupFromTlist = (isDone == ExprMultipleResult);
return result;
}
} else
InstrCountFiltered2(node, 1);
break;
case HJ_NEED_NEW_BATCH:
* Try to advance to next batch. Done if there are no more.
*/
if (!ExecHashJoinNewBatch(node)) {
ExecEarlyFree(outerPlanState(node));
EARLY_FREE_LOG(elog(LOG, "Early Free: HashJoin Probe is done"
" at node %d, memory used %d MB.",
(node->js.ps.plan)->plan_node_id, getSessionMemoryUsageMB()));
return NULL;
}
node->hj_JoinState = HJ_NEED_NEW_OUTER;
break;
default:
ereport(ERROR, (errcode(ERRCODE_UNEXPECTED_NODE_STATE),
errmodule(MOD_EXECUTOR), errmsg("unrecognized hashjoin state: %d", (int)node->hj_JoinState)));
}
}
}
* FindParam
*
* Walk through plan tree and find Param node.
* ----------------------------------------------------------------
*/
bool FindParam(Node* node_plan, void* context)
{
if (node_plan == NULL) {
return false;
}
if (IsA(node_plan, Param) && ((Param*)node_plan)->paramkind != PARAM_EXTERN) {
((PredpushPlanWalkerContext*)context)->predpush_stream = true;
return true;
}
if (IsA(node_plan, Stream)) {
return false;
}
return plan_tree_walker(node_plan, (MethodWalker)FindParam, (void*)context);
}
* CheckParamWalker
*
* Return true if we find a Param node in the plan tree.
* ----------------------------------------------------------------
*/
bool CheckParamWalker(PlanState* plan_stat)
{
Plan *temp_plan = plan_stat->plan;
if (plan_stat->state != NULL) {
PlannedStmt *temp_ps = plan_stat->state->es_plannedstmt;
PredpushPlanWalkerContext context;
errno_t rc = 0;
rc = memset_s(&context, sizeof(PredpushPlanWalkerContext), 0, sizeof(PredpushPlanWalkerContext));
securec_check(rc, "\0", "\0");
exec_init_plan_tree_base(&context.mpwc.base, temp_ps);
context.predpush_stream = false;
FindParam((Node*)temp_plan, &context);
return context.predpush_stream;
}
return true;
}
* ExecInitHashJoin
*
* Init routine for HashJoin node.
* ----------------------------------------------------------------
*/
HashJoinState* ExecInitHashJoin(HashJoin* node, EState* estate, int eflags)
{
HashJoinState* hjstate = NULL;
Plan* outerNode = NULL;
Hash* hashNode = NULL;
List* lclauses = NIL;
List* rclauses = NIL;
List* hoperators = NIL;
List* hcollations = NIL;
ListCell* l = NULL;
Assert(!(eflags & (EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK)));
* create state structure
*/
hjstate = makeNode(HashJoinState);
hjstate->js.ps.plan = (Plan*)node;
hjstate->js.ps.state = estate;
hjstate->hj_streamBothSides = node->streamBothSides;
hjstate->hj_rebuildHashtable = node->rebuildHashTable;
hjstate->js.ps.ExecProcNode = ExecHashJoin;
* Miscellaneous initialization
*
* create expression context for node
*/
ExecAssignExprContext(estate, &hjstate->js.ps);
* initialize child expressions
*/
if (estate->es_is_flt_frame) {
hjstate->js.ps.qual = (List*)ExecInitQualByFlatten(node->join.plan.qual, (PlanState*)hjstate);
hjstate->js.jointype = node->join.jointype;
hjstate->js.joinqual = (List*)ExecInitQualByFlatten(node->join.joinqual, (PlanState*)hjstate);
hjstate->js.nulleqqual = (List*)ExecInitQualByFlatten(node->join.nulleqqual, (PlanState*)hjstate);
hjstate->hashclauses = (List*)ExecInitQualByFlatten(node->hashclauses, (PlanState*)hjstate);
} else {
hjstate->js.ps.targetlist = (List*)ExecInitExprByRecursion((Expr*)node->join.plan.targetlist, (PlanState*)hjstate);
hjstate->js.ps.qual = (List*)ExecInitExprByRecursion((Expr*)node->join.plan.qual, (PlanState*)hjstate);
hjstate->js.jointype = node->join.jointype;
hjstate->js.joinqual = (List*)ExecInitExprByRecursion((Expr*)node->join.joinqual, (PlanState*)hjstate);
hjstate->js.nulleqqual = (List*)ExecInitExprByRecursion((Expr*)node->join.nulleqqual, (PlanState*)hjstate);
hjstate->hashclauses = (List*)ExecInitExprByRecursion((Expr*)node->hashclauses, (PlanState*)hjstate);
}
#ifdef USE_SPQ
if (IS_SPQ_RUNNING) {
if (JOIN_LASJ_NOTIN == node->join.jointype && node->hashqualclauses != nullptr) {
hjstate->hj_nonequijoin = true;
} else {
hjstate->hj_nonequijoin = false;
}
hjstate->prefetch_inner = node->join.prefetch_inner;
if (node->join.is_set_op_join) {
hjstate->hj_nonequijoin = true;
}
}
#endif
* initialize child nodes
*
* Note: we could suppress the REWIND flag for the inner input, which
* would amount to betting that the hash will be a single batch. Not
* clear if this would be a win or not.
*/
outerNode = outerPlan(node);
hashNode = (Hash*)innerPlan(node);
outerPlanState(hjstate) = ExecInitNode(outerNode, estate, eflags);
innerPlanState(hjstate) = ExecInitNode((Plan*)hashNode, estate, eflags);
#ifdef USE_SPQ
if (IS_SPQ_RUNNING) {
((HashState *)innerPlanState(hjstate))->hs_keepnull = hjstate->hj_nonequijoin;
}
#endif
* tuple table initialization
*/
ExecInitResultTupleSlot(estate, &hjstate->js.ps);
hjstate->hj_OuterTupleSlot = ExecInitExtraTupleSlot(estate);
hjstate->js.single_match = (node->join.inner_unique || node->join.jointype == JOIN_SEMI);
switch (node->join.jointype) {
case JOIN_INNER:
case JOIN_SEMI:
case JOIN_RIGHT_SEMI:
break;
case JOIN_LEFT:
case JOIN_ANTI:
case JOIN_LEFT_ANTI_FULL:
#ifdef USE_SPQ
case JOIN_LASJ_NOTIN:
#endif
hjstate->hj_NullInnerTupleSlot = ExecInitNullTupleSlot(estate, ExecGetResultType(innerPlanState(hjstate)));
break;
case JOIN_RIGHT:
case JOIN_RIGHT_ANTI:
case JOIN_RIGHT_ANTI_FULL:
hjstate->hj_NullOuterTupleSlot = ExecInitNullTupleSlot(estate, ExecGetResultType(outerPlanState(hjstate)));
break;
case JOIN_FULL:
hjstate->hj_NullOuterTupleSlot = ExecInitNullTupleSlot(estate, ExecGetResultType(outerPlanState(hjstate)));
hjstate->hj_NullInnerTupleSlot = ExecInitNullTupleSlot(estate, ExecGetResultType(innerPlanState(hjstate)));
break;
default:
ereport(ERROR,
(errcode(ERRCODE_UNRECOGNIZED_NODE_TYPE),
errmodule(MOD_EXECUTOR),
errmsg("unrecognized join type: %d for hashjoin", (int)node->join.jointype)));
}
* now for some voodoo. our temporary tuple slot is actually the result
* tuple slot of the Hash node (which is our inner plan). we can do this
* because Hash nodes don't return tuples via ExecProcNode() -- instead
* the hash join node uses ExecScanHashBucket() to get at the contents of
* the hash table. -cim 6/9/91
*/
{
HashState* hashstate = (HashState*)innerPlanState(hjstate);
TupleTableSlot* slot = hashstate->ps.ps_ResultTupleSlot;
hjstate->hj_HashTupleSlot = slot;
}
* initialize tuple type and projection info
* result tupleSlot only contains virtual tuple, so the default
* tableAm type is set to HEAP.
*/
ExecAssignResultTypeFromTL(&hjstate->js.ps);
ExecAssignProjectionInfo(&hjstate->js.ps, NULL);
ExecSetSlotDescriptor(hjstate->hj_OuterTupleSlot, ExecGetResultType(outerPlanState(hjstate)));
* initialize hash-specific info
*/
hjstate->hj_HashTable = NULL;
hjstate->hj_FirstOuterTupleSlot = NULL;
hjstate->hj_CurHashValue = 0;
hjstate->hj_CurBucketNo = 0;
hjstate->hj_CurSkewBucketNo = INVALID_SKEW_BUCKET_NO;
hjstate->hj_CurTuple = NULL;
* Deconstruct the hash clauses into outer and inner argument values, so
* that we can evaluate those subexpressions separately. Also make a list
* of the hash operator OIDs, in preparation for looking up the hash
* functions to use.
*/
lclauses = NIL;
rclauses = NIL;
hoperators = NIL;
if (estate->es_is_flt_frame) {
foreach (l, node->hashclauses) {
OpExpr *hclause = (OpExpr *)lfirst(l);
lclauses = lappend(lclauses, ExecInitExpr((Expr *)linitial(hclause->args), (PlanState *)hjstate));
rclauses = lappend(rclauses, ExecInitExpr((Expr *)lsecond(hclause->args), (PlanState *)hjstate));
hoperators = lappend_oid(hoperators, hclause->opno);
hcollations = lappend_oid(hcollations, hclause->inputcollid);
}
} else {
foreach (l, hjstate->hashclauses) {
FuncExprState *fstate = (FuncExprState *)lfirst(l);
OpExpr *hclause = NULL;
Assert(IsA(fstate, FuncExprState));
hclause = (OpExpr *)fstate->xprstate.expr;
Assert(IsA(hclause, OpExpr));
lclauses = lappend(lclauses, linitial(fstate->args));
rclauses = lappend(rclauses, lsecond(fstate->args));
hoperators = lappend_oid(hoperators, hclause->opno);
hcollations = lappend_oid(hcollations, hclause->inputcollid);
}
}
hjstate->hj_OuterHashKeys = lclauses;
hjstate->hj_InnerHashKeys = rclauses;
hjstate->hj_HashOperators = hoperators;
hjstate->hj_hashCollations = hcollations;
((HashState*)innerPlanState(hjstate))->hashkeys = rclauses;
hjstate->js.ps.ps_vec_TupFromTlist = false;
hjstate->hj_JoinState = HJ_BUILD_HASHTABLE;
hjstate->hj_MatchedOuter = false;
hjstate->hj_OuterNotEmpty = false;
return hjstate;
}
* ExecEndHashJoin
*
* clean up routine for HashJoin node
* ----------------------------------------------------------------
*/
void ExecEndHashJoin(HashJoinState* node)
{
* Free hash table
*/
if (node->hj_HashTable) {
ExecHashTableDestroy(node->hj_HashTable);
node->hj_HashTable = NULL;
}
* Free the exprcontext
*/
ExecFreeExprContext(&node->js.ps);
* clean out the tuple table
*/
(void)ExecClearTuple(node->js.ps.ps_ResultTupleSlot);
(void)ExecClearTuple(node->hj_OuterTupleSlot);
(void)ExecClearTuple(node->hj_HashTupleSlot);
* clean up subtrees
*/
ExecEndNode(outerPlanState(node));
ExecEndNode(innerPlanState(node));
}
* ExecHashJoinOuterGetTuple
*
* get the next outer tuple for hashjoin: either by
* executing the outer plan node in the first pass, or from
* the temp files for the hashjoin batches.
*
* Returns a null slot if no more outer tuples (within the current batch).
*
* On success, the tuple's hash value is stored at *hashvalue --- this is
* either originally computed, or re-read from the temp file.
*/
static TupleTableSlot* ExecHashJoinOuterGetTuple(PlanState* outerNode, HashJoinState* hjstate, uint32* hashvalue)
{
HashJoinTable hashtable = hjstate->hj_HashTable;
int curbatch = hashtable->curbatch;
TupleTableSlot* slot = NULL;
if (curbatch == 0) {
* Check to see if first outer tuple was already fetched by
* ExecHashJoin() and not used yet.
*/
slot = hjstate->hj_FirstOuterTupleSlot;
if (!TupIsNull(slot))
hjstate->hj_FirstOuterTupleSlot = NULL;
else
slot = ExecProcNode(outerNode);
while (!TupIsNull(slot)) {
* We have to compute the tuple's hash value.
*/
ExprContext* econtext = hjstate->js.ps.ps_ExprContext;
econtext->ecxt_outertuple = slot;
#ifdef USE_SPQ
bool hashkeys_null = false;
bool keep_nulls = (IS_SPQ_RUNNING) ?
(HJ_FILL_OUTER(hjstate) || hjstate->hj_nonequijoin) :
(HJ_FILL_OUTER(hjstate) || hjstate->js.nulleqqual != NIL);
if (ExecHashGetHashValue(hashtable,
econtext,
hjstate->hj_OuterHashKeys,
true,
keep_nulls,
hashvalue,
&hashkeys_null)) {
#else
if (ExecHashGetHashValue(hashtable,
econtext,
hjstate->hj_OuterHashKeys,
true,
HJ_FILL_OUTER(hjstate) || hjstate->js.nulleqqual != NIL,
hashvalue)) {
#endif
hjstate->hj_OuterNotEmpty = true;
return slot;
}
* That tuple couldn't match because of a NULL, so discard it and
* continue with the next one.
*/
slot = ExecProcNode(outerNode);
}
} else if (curbatch < hashtable->nbatch) {
BufFile* file = hashtable->outerBatchFile[curbatch];
* In outer-join cases, we could get here even though the batch file
* is empty.
*/
if (file == NULL)
return NULL;
slot = ExecHashJoinGetSavedTuple(hjstate, file, hashvalue, hjstate->hj_OuterTupleSlot);
if (!TupIsNull(slot))
return slot;
}
return NULL;
}
* ExecHashJoinNewBatch
* switch to a new hashjoin batch
*
* Returns true if successful, false if there are no more batches.
*/
static bool ExecHashJoinNewBatch(HashJoinState* hjstate)
{
HashJoinTable hashtable = hjstate->hj_HashTable;
int nbatch;
int curbatch;
BufFile* innerFile = NULL;
TupleTableSlot* slot = NULL;
uint32 hashvalue;
nbatch = hashtable->nbatch;
curbatch = hashtable->curbatch;
if (curbatch > 0) {
* We no longer need the previous outer batch file; close it right
* away to free disk space.
*/
if (hashtable->outerBatchFile[curbatch])
BufFileClose(hashtable->outerBatchFile[curbatch]);
hashtable->outerBatchFile[curbatch] = NULL;
} else {
* Reset some of the skew optimization state variables, since we no
* longer need to consider skew tuples after the first batch. The
* memory context reset we are about to do will release the skew
* hashtable itself.
*/
hashtable->skewEnabled = false;
hashtable->skewBucket = NULL;
hashtable->skewBucketNums = NULL;
hashtable->nSkewBuckets = 0;
hashtable->spaceUsedSkew = 0;
}
* We can always skip over any batches that are completely empty on both
* sides. We can sometimes skip over batches that are empty on only one
* side, but there are exceptions:
*
* 1. In a left/full outer join, we have to process outer batches even if
* the inner batch is empty. Similarly, in a right/full outer join, we
* have to process inner batches even if the outer batch is empty.
*
* 2. If we have increased nbatch since the initial estimate, we have to
* scan inner batches since they might contain tuples that need to be
* reassigned to later inner batches.
*
* 3. Similarly, if we have increased nbatch since starting the outer
* scan, we have to rescan outer batches in case they contain tuples that
* need to be reassigned.
*/
curbatch++;
while (curbatch < nbatch &&
(hashtable->outerBatchFile[curbatch] == NULL || hashtable->innerBatchFile[curbatch] == NULL)) {
if (hashtable->outerBatchFile[curbatch] && HJ_FILL_OUTER(hjstate))
break;
if (hashtable->innerBatchFile[curbatch] && HJ_FILL_INNER(hjstate))
break;
if (hashtable->innerBatchFile[curbatch] && nbatch != hashtable->nbatch_original)
break;
if (hashtable->outerBatchFile[curbatch] && nbatch != hashtable->nbatch_outstart)
break;
if (hashtable->innerBatchFile[curbatch])
BufFileClose(hashtable->innerBatchFile[curbatch]);
hashtable->innerBatchFile[curbatch] = NULL;
if (hashtable->outerBatchFile[curbatch])
BufFileClose(hashtable->outerBatchFile[curbatch]);
hashtable->outerBatchFile[curbatch] = NULL;
curbatch++;
}
if (curbatch >= nbatch) {
return false;
}
hashtable->curbatch = curbatch;
* Reload the hash table with the new inner batch (which could be empty)
*/
ExecHashTableReset(hashtable);
innerFile = hashtable->innerBatchFile[curbatch];
if (innerFile != NULL) {
if (BufFileSeek(innerFile, 0, 0L, SEEK_SET)) {
ereport(
ERROR, (errcode_for_file_access(), errmsg("could not rewind hash-join build side temporary file: %m")));
}
while ((slot = ExecHashJoinGetSavedTuple(hjstate, innerFile, &hashvalue, hjstate->hj_HashTupleSlot))) {
* NOTE: some tuples may be sent to future batches. Also, it is
* possible for hashtable->nbatch to be increased here!
*/
ExecHashTableInsert(hashtable,
slot,
hashvalue,
hjstate->js.ps.plan->righttree->plan_node_id,
SET_DOP(hjstate->js.ps.plan->righttree->dop));
}
if (anls_opt_is_on(ANLS_HASH_CONFLICT))
ExecHashTableStats(hashtable, hjstate->js.ps.plan->righttree->plan_node_id);
* after we build the hash table, the inner batch file is no longer
* needed
*/
BufFileClose(innerFile);
hashtable->innerBatchFile[curbatch] = NULL;
}
* Rewind outer batch file (if present), so that we can start reading it.
*/
if (hashtable->outerBatchFile[curbatch] != NULL) {
if (BufFileSeek(hashtable->outerBatchFile[curbatch], 0, 0L, SEEK_SET))
ereport(
ERROR, (errcode_for_file_access(), errmsg("could not rewind hash-join probe side temporary file: %m")));
}
return true;
}
* ExecHashJoinSaveTuple
* save a tuple to a batch file.
*
* The data recorded in the file for each tuple is its hash value,
* then the tuple in MinimalTuple format.
*
* Note: it is important always to call this in the regular executor
* context, not in a shorter-lived context; else the temp file buffers
* will get messed up.
*/
void ExecHashJoinSaveTuple(MinimalTuple tuple, uint32 hashvalue, BufFile** fileptr)
{
BufFile* file = *fileptr;
size_t written;
if (file == NULL) {
file = BufFileCreateTemp(false);
*fileptr = file;
}
written = BufFileWrite(file, (void*)&hashvalue, sizeof(uint32));
if (written != sizeof(uint32))
ereport(ERROR, (errcode_for_file_access(),
errmsg("could not write hashvalue %u to hash-join temporary file, written length %lu.",
hashvalue, written)));
written = BufFileWrite(file, (void*)tuple, tuple->t_len);
if (written != tuple->t_len)
ereport(ERROR, (errcode_for_file_access(),
errmsg("could not write tuple to hash-join temporary file: written length %lu, tuple length %u",
written, tuple->t_len)));
pgstat_increase_session_spill();
}
* ExecHashJoinGetSavedTuple
* read the next tuple from a batch file. Return NULL if no more.
*
* On success, *hashvalue is set to the tuple's hash value, and the tuple
* itself is stored in the given slot.
*/
static TupleTableSlot* ExecHashJoinGetSavedTuple(
HashJoinState* hjstate, BufFile* file, uint32* hashvalue, TupleTableSlot* tupleSlot)
{
uint32 header[2];
size_t nread;
MinimalTuple tuple;
* We check for interrupts here because this is typically taken as an
* alternative code path to an ExecProcNode() call, which would include
* such a check.
*/
CHECK_FOR_INTERRUPTS();
* Since both the hash value and the MinimalTuple length word are uint32,
* we can read them both in one BufFileRead() call without any type
* cheating.
*/
nread = BufFileRead(file, (void*)header, sizeof(header));
if (nread == 0) {
(void)ExecClearTuple(tupleSlot);
return NULL;
}
if (nread != sizeof(header)) {
ereport(ERROR, (errcode_for_file_access(),
errmsg("could not read from hash-join temporary file: read length %zu", nread)));
}
if (header[1] < sizeof(uint32)) {
ereport(ERROR, (errcode_for_file_access(),
errmsg("The hash-join temporary file is corrupted,hashvalue:%u, length:%u.", header[0], header[1])));
}
*hashvalue = header[0];
tuple = (MinimalTuple)palloc(header[1]);
tuple->t_len = header[1];
nread = BufFileRead(file, (void*)((char*)tuple + sizeof(uint32)), header[1] - sizeof(uint32));
if (nread != header[1] - sizeof(uint32)) {
ereport(ERROR, (errcode_for_file_access(),
errmsg("could not read from hash-join temporary file(t_len:%u,nread:%lu): %m",
header[1], (unsigned long)nread)));
}
return ExecStoreMinimalTuple(tuple, tupleSlot, true);
}
void ExecReScanHashJoin(HashJoinState* node)
{
if (node->js.ps.recursive_reset && node->js.ps.state->es_recursive_next_iteration) {
if (node->js.ps.righttree->chgParam == NULL)
ExecReScan(node->js.ps.righttree);
if (node->js.ps.lefttree->chgParam == NULL)
ExecReScan(node->js.ps.lefttree);
node->js.ps.recursive_reset = false;
return;
}
* In a multi-batch join, we currently have to do rescans the hard way,
* primarily because batch temp files may have already been released. But
* if it's a single-batch join, and there is no parameter change for the
* inner subnode, then we can just re-use the existing hash table without
* rebuilding it.
*/
if (node->hj_HashTable != NULL) {
if (!node->js.ps.plan->ispwj && node->hj_HashTable->nbatch == 1 && node->js.ps.righttree->chgParam == NULL &&
!node->hj_rebuildHashtable && node->js.jointype != JOIN_RIGHT_SEMI &&
node->js.jointype != JOIN_RIGHT_ANTI) {
* Okay to reuse the hash table; needn't rescan inner, either.
*
* However, if it's a right/full join, we'd better reset the
* inner-tuple match flags contained in the table.
*/
if (HJ_FILL_INNER(node))
ExecHashTableResetMatchFlags(node->hj_HashTable);
* Also, we need to reset our state about the emptiness of the
* outer relation, so that the new scan of the outer will update
* it correctly if it turns out to be empty this time. (There's no
* harm in clearing it now because ExecHashJoin won't need the
* info. In the other cases, where the hash table doesn't exist
* or we are destroying it, we leave this state alone because
* ExecHashJoin will need it the first time through.)
*/
node->hj_OuterNotEmpty = false;
node->hj_JoinState = HJ_NEED_NEW_OUTER;
} else {
ExecHashTableDestroy(node->hj_HashTable);
node->hj_HashTable = NULL;
node->hj_JoinState = HJ_BUILD_HASHTABLE;
* if chgParam of subnode is not null then plan will be re-scanned
* by first ExecProcNode.
*/
if (node->js.ps.righttree->chgParam == NULL)
ExecReScan(node->js.ps.righttree);
}
} else {
if (node->js.ps.plan->ispwj) {
node->hj_HashTable = NULL;
node->hj_JoinState = HJ_BUILD_HASHTABLE;
if (node->js.ps.righttree->chgParam == NULL) {
ExecReScan(node->js.ps.righttree);
}
}
}
node->hj_CurHashValue = 0;
node->hj_CurBucketNo = 0;
node->hj_CurSkewBucketNo = INVALID_SKEW_BUCKET_NO;
node->hj_CurTuple = NULL;
node->hj_MatchedOuter = false;
node->hj_FirstOuterTupleSlot = NULL;
* if chgParam of subnode is not null then plan will be re-scanned by
* first ExecProcNode.
*/
if (node->js.ps.lefttree->chgParam == NULL)
ExecReScan(node->js.ps.lefttree);
}
* @Description: Early free the memory for HashJoin.
*
* @param[IN] node: executor state for HashJoin
* @return: void
*/
void ExecEarlyFreeHashJoin(HashJoinState* node)
{
PlanState* plan_state = &node->js.ps;
if (plan_state->earlyFreed)
return;
* Free hash table
*/
if (node->hj_HashTable) {
ExecHashTableDestroy(node->hj_HashTable);
node->hj_HashTable = NULL;
* HashState.hashtable also point to hj_HashTable(check ExecHashJoin),
* so set it to null directly to avoid heap-use-after-free
*/
HashState* hash_state = (HashState*)innerPlanState(node);
hash_state->hashtable = NULL;
}
* Free the exprcontext
*/
ExecFreeExprContext(&node->js.ps);
* clean out the tuple table
*/
(void)ExecClearTuple(node->js.ps.ps_ResultTupleSlot);
(void)ExecClearTuple(node->hj_OuterTupleSlot);
(void)ExecClearTuple(node->hj_HashTupleSlot);
EARLY_FREE_LOG(elog(LOG,
"Early Free: After early freeing HashJoin "
"at node %d, memory used %d MB.",
plan_state->plan->plan_node_id,
getSessionMemoryUsageMB()));
plan_state->earlyFreed = true;
ExecEarlyFree(innerPlanState(node));
ExecEarlyFree(outerPlanState(node));
}
* @Function: ExecReSetHashJoin()
*
* @Brief: Reset the hashjoin state structure including have hashtable be recreated
* so that in next round of iteration, the data of inner side is correct
*
* @Input node: hashjoin planstate node
*
* @Return: no return value
*/
void ExecReSetHashJoin(HashJoinState* node)
{
Assert(EXEC_IN_RECURSIVE_MODE(node->js.ps.plan));
if (node->hj_HashTable != NULL) {
ExecHashTableDestroy(node->hj_HashTable);
node->hj_HashTable = NULL;
node->hj_JoinState = HJ_BUILD_HASHTABLE;
}
ExecReSetRecursivePlanTree(node->js.ps.righttree);
node->hj_CurHashValue = 0;
node->hj_CurBucketNo = 0;
node->hj_CurSkewBucketNo = INVALID_SKEW_BUCKET_NO;
node->hj_CurTuple = NULL;
node->js.ps.ps_vec_TupFromTlist = false;
node->hj_MatchedOuter = false;
node->hj_FirstOuterTupleSlot = NULL;
node->js.ps.recursive_reset = true;
* if chgParam of subnode is not null then plan will be re-scanned by
* first ExecProcNode.
*/
if (node->js.ps.lefttree->chgParam == NULL)
ExecReSetRecursivePlanTree(node->js.ps.lefttree);
}