/*-------------------------------------------------------------------------
*
* pg_hint_plan.c
- * do instructions or hints to the planner using C-style block comments
- * of the SQL.
+ * hinting on how to execute a query for PostgreSQL
*
- * Copyright (c) 2012-2016, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
+ * Copyright (c) 2012-2017, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
*
*-------------------------------------------------------------------------
*/
int init_parasetup_cost;/* parallel_setup_cost */
Index parent_relid; /* inherit parent of table relid */
- ScanMethodHint *parent_hint; /* inherit parent of table scan hint */
+ ScanMethodHint *parent_scan_hint; /* scan hint for the parent */
+ ParallelHint *parent_parallel_hint; /* parallel hint for the parent */
List *parent_index_infos; /* list of parent table's index */
JoinMethodHint **join_hints; /* parsed join hints */
DestReceiver *dest, char *completionTag);
static PlannedStmt *pg_hint_plan_planner(Query *parse, int cursorOptions,
ParamListInfo boundParams);
-static void pg_hint_plan_get_relation_info(PlannerInfo *root,
- Oid relationObjectId,
- bool inhparent, RelOptInfo *rel);
static RelOptInfo *pg_hint_plan_join_search(PlannerInfo *root,
int levels_needed,
List *initial_rels);
RelOptInfo *old_rel,
ListCell *other_rels);
static bool has_join_restriction(PlannerInfo *root, RelOptInfo *rel);
+static void set_plain_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
+ RangeTblEntry *rte);
static void set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
Index rti, RangeTblEntry *rte);
static void generate_mergeappend_paths(PlannerInfo *root, RelOptInfo *rel,
bool isCommit,
bool isTopLevel,
void *arg);
-static int set_config_option_wrapper(const char *name, const char *value,
+static int set_config_option_noerror(const char *name, const char *value,
GucContext context, GucSource source,
GucAction action, bool changeVal, int elevel);
-static void set_scan_config_options(unsigned char enforce_mask,
- GucContext context);
-static void set_config_int32_option(const char *name, int32 value,
+static void setup_scan_method_enforcement(ScanMethodHint *scanhint,
+ HintState *state);
+static int set_config_int32_option(const char *name, int32 value,
GucContext context);
/* GUC variables */
/* Saved hook values in case of unload */
static ProcessUtility_hook_type prev_ProcessUtility = NULL;
static planner_hook_type prev_planner = NULL;
-static get_relation_info_hook_type prev_get_relation_info = NULL;
static join_search_hook_type prev_join_search = NULL;
static set_rel_pathlist_hook_type prev_set_rel_pathlist = NULL;
ProcessUtility_hook = pg_hint_plan_ProcessUtility;
prev_planner = planner_hook;
planner_hook = pg_hint_plan_planner;
- prev_get_relation_info = get_relation_info_hook;
- get_relation_info_hook = pg_hint_plan_get_relation_info;
prev_join_search = join_search_hook;
join_search_hook = pg_hint_plan_join_search;
prev_set_rel_pathlist = set_rel_pathlist_hook;
/* Uninstall hooks. */
ProcessUtility_hook = prev_ProcessUtility;
planner_hook = prev_planner;
- get_relation_info_hook = prev_get_relation_info;
join_search_hook = prev_join_search;
set_rel_pathlist_hook = prev_set_rel_pathlist;
hstate->init_paratup_cost = 0;
hstate->init_parasetup_cost = 0;
hstate->parent_relid = 0;
- hstate->parent_hint = NULL;
+ hstate->parent_scan_hint = NULL;
+ hstate->parent_parallel_hint = NULL;
hstate->parent_index_infos = NIL;
hstate->join_hints = NULL;
hstate->init_join_mask = 0;
return mask;
}
+/*
+ * Sets GUC prameters without throwing exception. Reutrns false if something
+ * wrong.
+ */
static int
-set_config_option_wrapper(const char *name, const char *value,
+set_config_option_noerror(const char *name, const char *value,
GucContext context, GucSource source,
GucAction action, bool changeVal, int elevel)
{
return result;
}
+/*
+ * Sets GUC parameter of int32 type without throwing exceptions. Returns false
+ * if something wrong.
+ */
static int
-set_config_options(SetHint **options, int noptions, GucContext context)
+set_config_int32_option(const char *name, int32 value, GucContext context)
{
- int i;
- int save_nestlevel;
+ char buf[16]; /* enough for int32 */
- save_nestlevel = NewGUCNestLevel();
+ if (snprintf(buf, 16, "%d", value) < 0)
+ {
+ ereport(pg_hint_plan_message_level,
+ (errmsg ("Cannot set integer value: %d: %s",
+ max_hint_nworkers, strerror(errno))));
+ return false;
+ }
+
+ return
+ set_config_option_noerror(name, buf, context,
+ PGC_S_SESSION, GUC_ACTION_SAVE, true,
+ pg_hint_plan_message_level);
+}
+
+/* setup scan method enforcement according to given options */
+static void
+setup_guc_enforcement(SetHint **options, int noptions, GucContext context)
+{
+ int i;
for (i = 0; i < noptions; i++)
{
if (!hint_state_enabled(hint))
continue;
- result = set_config_option_wrapper(hint->name, hint->value, context,
+ result = set_config_option_noerror(hint->name, hint->value, context,
PGC_S_SESSION, GUC_ACTION_SAVE, true,
pg_hint_plan_message_level);
if (result != 0)
hint->base.state = HINT_STATE_ERROR;
}
- return save_nestlevel;
-}
-
-static void
-set_config_int32_option(const char *name, int32 value, GucContext context)
-{
- char buf[16]; /* enough for int32 */
-
- if (snprintf(buf, 16, "%d", value) < 0)
- {
- ereport(pg_hint_plan_message_level,
- (errmsg ("Cannot set integer value: %d: %s",
- max_hint_nworkers, strerror(errno))));
- return;
- }
-
- set_config_option_wrapper(name, buf, context,
- PGC_S_SESSION, GUC_ACTION_SAVE, true,
- pg_hint_plan_message_level);
+ return;
}
-
/*
- * Setup parallel execution environment. If init == true, it is set to the
- * initial values in state, elsewise set to values in hint.
+ * Setup parallel execution environment.
+ *
+ * If hint is not NULL, set up using it, elsewise reset to initial environment.
*/
static void
-setup_parallel_scan(ParallelHint *hint, bool init, HintState *state)
+setup_parallel_plan_enforcement(ParallelHint *hint, HintState *state)
{
- /* !init requires hint */
- Assert(init|| hint);
-
- if (init)
+ if (hint)
+ {
+ hint->base.state = HINT_STATE_USED;
set_config_int32_option("max_parallel_workers_per_gather",
- state->init_nworkers, state->context);
+ hint->nworkers, state->context);
+ }
else
set_config_int32_option("max_parallel_workers_per_gather",
- hint->nworkers, state->context);
+ state->init_nworkers, state->context);
/* force means that enforce parallel as far as possible */
- if (!init && hint->force_parallel)
+ if (hint && hint->force_parallel)
{
set_config_int32_option("parallel_tuple_cost", 0, state->context);
set_config_int32_option("parallel_setup_cost", 0, state->context);
}
#define SET_CONFIG_OPTION(name, type_bits) \
- set_config_option_wrapper((name), \
+ set_config_option_noerror((name), \
(mask & (type_bits)) ? "true" : "false", \
context, PGC_S_SESSION, GUC_ACTION_SAVE, true, ERROR)
+
+/*
+ * Setup GUC environment to enforce scan methods. If scanhint is NULL, reset
+ * GUCs to the saved state in state.
+ */
static void
-set_scan_config_options(unsigned char enforce_mask, GucContext context)
+setup_scan_method_enforcement(ScanMethodHint *scanhint, HintState *state)
{
+ unsigned char enforce_mask = state->init_scan_mask;
+ GucContext context = state->context;
unsigned char mask;
+ if (scanhint)
+ {
+ enforce_mask = scanhint->enforce_mask;
+ scanhint->base.state = HINT_STATE_USED;
+ }
+
if (enforce_mask == ENABLE_SEQSCAN || enforce_mask == ENABLE_INDEXSCAN ||
enforce_mask == ENABLE_BITMAPSCAN || enforce_mask == ENABLE_TIDSCAN
|| enforce_mask == (ENABLE_INDEXSCAN | ENABLE_INDEXONLYSCAN)
*/
push_hint(hstate);
- /* Set GUC parameters which are specified with Set hint. */
- save_nestlevel =
- set_config_options(current_hint_state->set_hints,
+ /* Set scan enforcement here. */
+ save_nestlevel = NewGUCNestLevel();
+
+ /* Apply Set hints, then save it as the initial state */
+ setup_guc_enforcement(current_hint_state->set_hints,
current_hint_state->num_hints[HINT_TYPE_SET],
current_hint_state->context);
- /* save current status to current_hint_state */
current_hint_state->init_scan_mask = get_current_scan_mask();
current_hint_state->init_join_mask = get_current_join_mask();
current_hint_state->init_min_para_size = min_parallel_relation_size;
* max_parallel_workers_per_gather should be non-zero here if Workers hint
* is specified.
*/
- if (max_hint_nworkers >= 0)
- {
- current_hint_state->init_nworkers = 0;
+ if (max_hint_nworkers > 0 && max_parallel_workers_per_gather < 1)
set_config_int32_option("max_parallel_workers_per_gather",
1, current_hint_state->context);
- }
+ current_hint_state->init_nworkers = max_parallel_workers_per_gather;
if (debug_level > 1)
{
}
/*
- * Return scan method hint which matches given aliasname.
+ * Find scan method hint to be applied to the given relation
*/
static ScanMethodHint *
find_scan_hint(PlannerInfo *root, Index relid, RelOptInfo *rel)
* - not a base relation and inheritance children
* - not an ordinary relation (such as join and subquery)
*/
- if (rel && ((rel->reloptkind != RELOPT_BASEREL &&
- rel->reloptkind != RELOPT_OTHER_MEMBER_REL) ||
- rel->rtekind != RTE_RELATION))
+ if (!rel || rel->rtekind != RTE_RELATION ||
+ (rel->reloptkind != RELOPT_BASEREL &&
+ rel->reloptkind != RELOPT_OTHER_MEMBER_REL))
return NULL;
rte = root->simple_rte_array[relid];
return DatumGetBool(result);
}
+
+/* Remove indexes instructed not to use by hint. */
static void
-delete_indexes(ScanMethodHint *hint, RelOptInfo *rel, Oid relationObjectId)
+restrict_indexes(PlannerInfo *root, ScanMethodHint *hint, RelOptInfo *rel,
+ bool using_parent_hint)
{
ListCell *cell;
ListCell *prev;
ListCell *next;
StringInfoData buf;
+ RangeTblEntry *rte = root->simple_rte_array[rel->relid];
+ Oid relationObjectId = rte->relid;
/*
* We delete all the IndexOptInfo list and prevent you from being usable by
}
/*
- * to make the index a candidate when definition of this index is
- * matched with the index's definition of current_hint_state.
+ * Apply index restriction of parent hint to children. Since index
+ * inheritance is not explicitly described we should search for an
+ * children's index with the same definition to that of the parent.
*/
- if (OidIsValid(relationObjectId) && !use_index)
+ if (using_parent_hint && !use_index)
{
foreach(l, current_hint_state->parent_index_infos)
{
HeapTuple ht_idx;
ParentIndexInfo *p_info = (ParentIndexInfo *)lfirst(l);
- /* check to match the parameter of unique */
- if (p_info->indisunique != info->unique)
- continue;
-
- /* check to match the parameter of index's method */
- if (p_info->method != info->relam)
- continue;
-
- /* to check to match the indexkey's configuration */
- if ((list_length(p_info->column_names)) !=
- info->ncolumns)
+ /*
+ * we check the 'same' index by comparing uniqueness, access
+ * method and index key columns.
+ */
+ if (p_info->indisunique != info->unique ||
+ p_info->method != info->relam ||
+ list_length(p_info->column_names) != info->ncolumns)
continue;
- /* check to match the indexkey's configuration */
+ /* Check if index key columns match */
for (i = 0; i < info->ncolumns; i++)
{
char *c_attname = NULL;
char *p_attname = NULL;
- p_attname =
- list_nth(p_info->column_names, i);
+ p_attname = list_nth(p_info->column_names, i);
- /* both are expressions */
+ /*
+ * if both of the key of the same position are expressions,
+ * ignore them for now and check later.
+ */
if (info->indexkeys[i] == 0 && !p_attname)
continue;
- /* one's column is expression, the other is not */
+ /* deny if one is expression while another is not */
if (info->indexkeys[i] == 0 || !p_attname)
break;
c_attname = get_attname(relationObjectId,
info->indexkeys[i]);
- if (strcmp(p_attname, c_attname) != 0)
- break;
-
- if (p_info->indcollation[i] != info->indexcollations[i])
+ /* deny if any of column attributes don't match */
+ if (strcmp(p_attname, c_attname) != 0 ||
+ p_info->indcollation[i] != info->indexcollations[i] ||
+ p_info->opclass[i] != info->opcintype[i]||
+ ((p_info->indoption[i] & INDOPTION_DESC) != 0)
+ != info->reverse_sort[i] ||
+ ((p_info->indoption[i] & INDOPTION_NULLS_FIRST) != 0)
+ != info->nulls_first[i])
break;
-
- if (p_info->opclass[i] != info->opcintype[i])
- break;
-
- if (((p_info->indoption[i] & INDOPTION_DESC) != 0) !=
- info->reverse_sort[i])
- break;
-
- if (((p_info->indoption[i] & INDOPTION_NULLS_FIRST) != 0) !=
- info->nulls_first[i])
- break;
-
}
+ /* deny this if any difference found */
if (i != info->ncolumns)
continue;
+ /* check on key expressions */
if ((p_info->expression_str && (info->indexprs != NIL)) ||
(p_info->indpred_str && (info->indpred != NIL)))
{
- /*
- * Fetch the pg_index tuple by the Oid of the index
- */
+ /* fetch the index of this child */
ht_idx = SearchSysCache1(INDEXRELID,
ObjectIdGetDatum(info->indexoid));
- /* check to match the expression's parameter of index */
+ /* check expressions if both expressions are available */
if (p_info->expression_str &&
!heap_attisnull(ht_idx, Anum_pg_index_indexprs))
{
ObjectIdGetDatum(
relationObjectId));
+ /* deny if expressions don't match */
if (strcmp(p_info->expression_str,
text_to_cstring(DatumGetTextP(result))) != 0)
{
/* Clean up */
ReleaseSysCache(ht_idx);
-
continue;
}
}
- /* Check to match the predicate's parameter of index */
+ /* compare index predicates */
if (p_info->indpred_str &&
!heap_attisnull(ht_idx, Anum_pg_index_indpred))
{
bool isnull;
Datum result;
- /*
- * to change the predicate's parameter of child's
- * index to strings
- */
predDatum = SysCacheGetAttr(INDEXRELID, ht_idx,
Anum_pg_index_indpred,
&isnull);
{
/* Clean up */
ReleaseSysCache(ht_idx);
-
continue;
}
}
if (debug_level == 1)
{
- char *relname;
StringInfoData rel_buf;
+ char *disprelname = "";
- if (OidIsValid(relationObjectId))
- relname = get_rel_name(relationObjectId);
+ /*
+ * If this hint targetted the parent, use the real name of this
+ * child. Otherwise use hint specification.
+ */
+ if (using_parent_hint)
+ disprelname = get_rel_name(rte->relid);
else
- relname = hint->relname;
+ disprelname = hint->relname;
+
initStringInfo(&rel_buf);
- quote_value(&rel_buf, relname);
+ quote_value(&rel_buf, disprelname);
ereport(LOG,
(errmsg("available indexes for %s(%s):%s",
return p_info;
}
+/*
+ * cancel hint enforcement
+ */
static void
-process_scanmethod_hints(PlannerInfo *root, Oid relationObjectId,
- bool inhparent, RelOptInfo *rel)
+reset_hint_enforcement()
{
- Index new_parent_relid = 0;
+ setup_scan_method_enforcement(NULL, current_hint_state);
+ setup_parallel_plan_enforcement(NULL, current_hint_state);
+}
+
+/*
+ * Set planner guc parameters according to corresponding scan hints.
+ */
+static bool
+setup_hint_enforcement(PlannerInfo *root, RelOptInfo *rel)
+{
+ Index new_parent_relid = 0;
ListCell *l;
- ScanMethodHint *scanhint = NULL;
+ ScanMethodHint *shint = NULL;
+ ParallelHint *phint = NULL;
+ bool inhparent = root->simple_rte_array[rel->relid]->inh;
+ Oid relationObjectId = root->simple_rte_array[rel->relid]->relid;
/*
* We could register the parent relation of the following children here
- * when inhparent == true but inheritnce planner doesn't request
- * information for inheritance parents. We also cannot distinguish the
- * caller so we should always find the parents without this function being
- * called for them.
+ * when inhparent == true but inheritnce planner doesn't call this function
+ * for parents. Since we cannot distinguish who called this function we
+ * cannot do other than always seeking the parent regardless of who called
+ * this function.
*/
if (inhparent)
{
if (debug_level > 1)
ereport(pg_hint_plan_message_level,
(errhidestmt(true),
- errmsg ("pg_hint_plan%s: get_relation_info"
+ errmsg ("pg_hint_plan%s: setup_hint_enforcement"
" skipping inh parent: relation=%u(%s), inhparent=%d,"
" current_hint_state=%p, hint_inhibit_level=%d",
qnostr, relationObjectId,
get_rel_name(relationObjectId),
inhparent, current_hint_state, hint_inhibit_level)));
- return;
+ return false;
}
- /* Find the parent for this relation */
+ /* Find the parent for this relation other than the registered parent */
foreach (l, root->append_rel_list)
{
AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l);
{
/* This relation doesn't have a parent. Cancel current_hint_state. */
current_hint_state->parent_relid = 0;
- current_hint_state->parent_hint = NULL;
+ current_hint_state->parent_scan_hint = NULL;
+ current_hint_state->parent_parallel_hint = NULL;
}
if (new_parent_relid > 0)
* hint to other childrens of this parent so remember it * to avoid
* hinthintredundant setup cost.
*/
- bool use_parent_env = false;
- ScanMethodHint *parent_hint = NULL;
-
current_hint_state->parent_relid = new_parent_relid;
- /* Check if the parent has a hint */
- current_hint_state->parent_hint = parent_hint =
+ /* Find hints for the parent */
+ current_hint_state->parent_scan_hint =
find_scan_hint(root, current_hint_state->parent_relid, NULL);
- if (parent_hint)
+ current_hint_state->parent_parallel_hint =
+ find_parallel_hint(root, current_hint_state->parent_relid, NULL);
+
+ /*
+ * If hint is found for the parent, apply it for this child instead
+ * of its own.
+ */
+ if (current_hint_state->parent_scan_hint)
{
- /* If hint is found for the parent, apply its hint instead. */
- use_parent_env = true;
- parent_hint->base.state = HINT_STATE_USED;
+ ScanMethodHint * pshint = current_hint_state->parent_scan_hint;
+
+ pshint->base.state = HINT_STATE_USED;
- /* Resolve index name mask (if any) using the parent. */
- if (parent_hint->indexnames)
+ /* Apply index mask in the same manner to the parent. */
+ if (pshint->indexnames)
{
Oid parentrel_oid;
Relation parent_rel;
ListCell *lc;
ParentIndexInfo *parent_index_info;
- foreach(lc, parent_hint->indexnames)
+ foreach(lc, pshint->indexnames)
{
if (RelnameCmp(&indexname, &lfirst(lc)) == 0)
break;
parent_index_info =
get_parent_index_info(indexoid, parentrel_oid);
current_hint_state->parent_index_infos =
- lappend(current_hint_state->parent_index_infos, parent_index_info);
+ lappend(current_hint_state->parent_index_infos,
+ parent_index_info);
}
heap_close(parent_rel, NoLock);
}
}
-
- if (use_parent_env)
- set_scan_config_options(parent_hint->enforce_mask,
- current_hint_state->context);
- else
- set_scan_config_options(current_hint_state->init_scan_mask,
- current_hint_state->context);
}
- /* Process index restriction hint inheritance */
- if (current_hint_state->parent_hint != 0)
- {
- delete_indexes(current_hint_state->parent_hint, rel,
- relationObjectId);
-
- /* Scan fixation status is the same to the parent. */
- if (debug_level > 1)
- ereport(pg_hint_plan_message_level,
- (errhidestmt(true),
- errmsg("pg_hint_plan%s: get_relation_info:"
- " index deletion by parent hint: "
- "relation=%u(%s), inhparent=%d, current_hint_state=%p,"
- " hint_inhibit_level=%d",
- qnostr, relationObjectId,
- get_rel_name(relationObjectId),
- inhparent, current_hint_state, hint_inhibit_level)));
- return;
- }
+ if (current_hint_state->parent_scan_hint)
+ shint = current_hint_state->parent_scan_hint;
+ else
+ shint = find_scan_hint(root, rel->relid, rel);
- /* This table doesn't have a parent hint. Apply its own hint if any. */
- if ((scanhint = find_scan_hint(root, rel->relid, rel)) != NULL)
+ if (shint)
{
- set_scan_config_options(scanhint->enforce_mask,
- current_hint_state->context);
- scanhint->base.state = HINT_STATE_USED;
+ bool using_parent_hint =
+ (shint == current_hint_state->parent_scan_hint);
- delete_indexes(scanhint, rel, InvalidOid);
+ /* Setup scan enforcement environment */
+ setup_scan_method_enforcement(shint, current_hint_state);
+
+ /* restrict unwanted inexes */
+ restrict_indexes(root, shint, rel, using_parent_hint);
if (debug_level > 1)
+ {
+ char *additional_message = "";
+
+ if (shint == current_hint_state->parent_scan_hint)
+ additional_message = " by parent hint";
+
ereport(pg_hint_plan_message_level,
(errhidestmt(true),
- errmsg ("pg_hint_plan%s: get_relation_info"
- " index deletion:"
- " relation=%u(%s), inhparent=%d, current_hint=%p,"
+ errmsg ("pg_hint_plan%s: setup_hint_enforcement"
+ " index deletion%s:"
+ " relation=%u(%s), inhparent=%d, "
+ "current_hint_state=%p,"
" hint_inhibit_level=%d, scanmask=0x%x",
- qnostr, relationObjectId,
+ qnostr, additional_message,
+ relationObjectId,
get_rel_name(relationObjectId),
- inhparent, current_hint_state, hint_inhibit_level,
- scanhint->enforce_mask)));
- return;
+ inhparent, current_hint_state,
+ hint_inhibit_level,
+ shint->enforce_mask)));
+ }
}
- /* Nothing to apply. Reset the scan mask to intial state */
- if (debug_level > 1)
- ereport(pg_hint_plan_message_level,
- (errhidestmt (true),
- errmsg ("pg_hint_plan%s: get_relation_info"
- " no hint applied:"
- " relation=%u(%s), inhparent=%d, current_hint=%p,"
- " hint_inhibit_level=%d, scanmask=0x%x",
- qnostr, relationObjectId,
- get_rel_name(relationObjectId),
- inhparent, current_hint_state, hint_inhibit_level,
- current_hint_state->init_scan_mask)));
- set_scan_config_options(current_hint_state->init_scan_mask,
- current_hint_state->context);
-}
-
-static void
-pg_hint_plan_get_relation_info(PlannerInfo *root, Oid relationObjectId,
- bool inhparent, RelOptInfo *rel)
-{
- ParallelHint *parallelhint = NULL;
+ /* Do the same for parallel plan enforcement */
+ if (current_hint_state->parent_parallel_hint)
+ phint = current_hint_state->parent_parallel_hint;
+ else
+ phint = find_parallel_hint(root, rel->relid, rel);
- if (prev_get_relation_info)
- (*prev_get_relation_info) (root, relationObjectId, inhparent, rel);
+ setup_parallel_plan_enforcement(phint, current_hint_state);
- /*
- * Do nothing if we don't have a valid hint in this context or current
- * nesting depth is at SPI calls.
- */
- if (!current_hint_state || hint_inhibit_level > 0)
+ /* Nothing to apply. Reset the scan mask to intial state */
+ if (!shint && ! phint)
{
if (debug_level > 1)
ereport(pg_hint_plan_message_level,
(errhidestmt (true),
errmsg ("pg_hint_plan%s: get_relation_info"
- " no hint to apply: relation=%u(%s), inhparent=%d,"
- " current_hint_state=%p, hint_inhibit_level=%d",
+ " no hint applied:"
+ " relation=%u(%s), inhparent=%d, current_hint=%p,"
+ " hint_inhibit_level=%d, scanmask=0x%x",
qnostr, relationObjectId,
get_rel_name(relationObjectId),
- inhparent, current_hint_state, hint_inhibit_level)));
- return;
- }
+ inhparent, current_hint_state, hint_inhibit_level,
+ current_hint_state->init_scan_mask)));
- process_scanmethod_hints(root, relationObjectId, inhparent, rel);
+ setup_scan_method_enforcement(NULL, current_hint_state);
- /*
- * Parallel hint doesn't inherit, process separately from other types of
- * hint
- */
- if ((parallelhint = find_parallel_hint(root, rel->relid, rel)) != NULL)
- {
- /* Set parallel environment according to the hint */
- setup_parallel_scan(parallelhint, false, current_hint_state);
- }
- else
- {
- /* Reset parallel environment */
- setup_parallel_scan(NULL, true, current_hint_state);
+ return false;
}
- return;
+
+ return true;
}
/*
}
/*
- * set_plain_rel_pathlist
- * Build access paths for a plain relation (no subquery, no inheritance)
- *
- * This function was copied and edited from set_plain_rel_pathlist() in
- * src/backend/optimizer/path/allpaths.c
- *
- * - removed parallel stuff.
- */
-static void
-set_plain_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
-{
- Relids required_outer;
-
- /*
- * We don't support pushing join clauses into the quals of a seqscan, but
- * it could still have required parameterization due to LATERAL refs in
- * its tlist.
- */
- required_outer = rel->lateral_relids;
-
- /* Consider sequential scan */
- add_path(rel, create_seqscan_path(root, rel, required_outer, 0));
-
- /* If appropriate, consider parallel sequential scan */
- if (rel->consider_parallel && required_outer == NULL)
- {
- ParallelHint *phint = find_parallel_hint(root, rel->relid, rel);
-
- /* Consider parallel paths only if not inhibited by hint */
- if (!phint || phint->nworkers > 0)
- create_plain_partial_paths(root, rel);
-
- /*
- * Overwirte parallel_workers if requested. partial_pathlist seems to
- * have up to one path but looping over all possible paths don't harm.
- */
- if (phint && phint->nworkers > 0 && phint->force_parallel)
- {
- ListCell *l;
- foreach (l, rel->partial_pathlist)
- {
- Path *ppath = (Path *) lfirst(l);
-
- Assert(ppath->parallel_workers > 0);
- ppath->parallel_workers = phint->nworkers;
- }
- }
- }
-
- /* Consider index scans */
- create_index_paths(root, rel);
-
- /* Consider TID scans */
- create_tidscan_paths(root, rel);
-}
-
-/*
- * Clear exiting access paths and create new ones applying hints.
- * This does the similar to set_rel_pathlist
- */
-static void
-rebuild_scan_path(HintState *hstate, PlannerInfo *root, int level,
- List *initial_rels)
-{
- ListCell *l;
-
- foreach(l, initial_rels)
- {
- RelOptInfo *rel = (RelOptInfo *) lfirst(l);
- RangeTblEntry *rte;
- ScanMethodHint *scanhint;
- ParallelHint *parallelhint;
-
- /* Skip relations which we can't choose scan method. */
- if (rel->reloptkind != RELOPT_BASEREL || rel->rtekind != RTE_RELATION)
- continue;
-
- rte = root->simple_rte_array[rel->relid];
-
- /* We can't force scan method of foreign tables */
- if (rte->relkind == RELKIND_FOREIGN_TABLE)
- continue;
-
- /*
- * Create scan paths with GUC parameters which are at the beginning of
- * planner if scan method hint is not specified, otherwise use
- * specified hints and mark the hint as used.
- */
- if ((scanhint = find_scan_hint(root, rel->relid, rel)) == NULL)
- set_scan_config_options(hstate->init_scan_mask,
- hstate->context);
- else
- {
- set_scan_config_options(scanhint->enforce_mask, hstate->context);
- scanhint->base.state = HINT_STATE_USED;
- }
-
- if ((parallelhint = find_parallel_hint(root, rel->relid, rel)) != NULL)
- {
- /* Set parallel environment according to the hint */
- setup_parallel_scan(parallelhint, false, current_hint_state);
- }
- else
- {
- /* Reset parallel environment */
- setup_parallel_scan(NULL, true, current_hint_state);
- }
-
- /* remove existing partial paths from this baserel */
- list_free_deep(rel->partial_pathlist);
- rel->partial_pathlist = NIL;
-
- /* remove existing paths from this baserel */
- list_free_deep(rel->pathlist);
- rel->pathlist = NIL;
-
- if (rte->inh)
- {
- ListCell *l;
-
- /* remove partial paths from all chlidren */
- foreach (l, root->append_rel_list)
- {
- AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l);
- RelOptInfo *childrel;
-
- if (appinfo->parent_relid != rel->relid)
- continue;
-
- childrel = root->simple_rel_array[appinfo->child_relid];
- list_free_deep(childrel->partial_pathlist);
- childrel->partial_pathlist = NIL;
- }
- /* It's an "append relation", process accordingly */
- set_append_rel_pathlist(root, rel, rel->relid, rte);
- }
- else
- {
- set_plain_rel_pathlist(root, rel, rte);
- }
-
- /*
- * If this is a baserel, consider gathering any partial paths we may
- * hinthave created for it.
- */
- if (rel->reloptkind == RELOPT_BASEREL)
- generate_gather_paths(root, rel);
-
- /* Now find the cheapest of the paths for this rel */
- set_cheapest(rel);
- }
-
- /*
- * Restore the GUC variables we set above.
- */
- set_scan_config_options(hstate->init_scan_mask, hstate->context);
-}
-
-/*
* wrapper of make_join_rel()
*
* call make_join_rel() after changing enable_* parameters according to given
int save_nestlevel;
if ((scan_hint = find_scan_hint(root, innerrel->relid, innerrel)) != NULL)
- {
- set_scan_config_options(scan_hint->enforce_mask,
- current_hint_state->context);
- scan_hint->base.state = HINT_STATE_USED;
- }
+ setup_scan_method_enforcement(scan_hint, current_hint_state);
joinrelids = bms_union(outerrel->relids, innerrel->relids);
join_hint = find_join_hint(joinrelids);
add_paths_to_joinrel(root, joinrel, outerrel, innerrel, jointype,
sjinfo, restrictlist);
+ /* Reset the environment if changed */
if (scan_hint != NULL)
- set_scan_config_options(current_hint_state->init_scan_mask,
- current_hint_state->context);
+ setup_scan_method_enforcement(NULL, current_hint_state);
}
static int
return standard_join_search(root, levels_needed, initial_rels);
}
- /* apply scan method hint rebuild scan path. */
- rebuild_scan_path(current_hint_state, root, levels_needed, initial_rels);
-
/*
* In the case using GEQO, only scan method hints and Set hints have
* effect. Join method and join order is not controllable by hints.
Index rti, RangeTblEntry *rte)
{
ParallelHint *phint;
- List *oldpathlist;
ListCell *l;
- bool regenerate = false;
- /* Hint has not been parsed yet, or this is not a parallel'able relation */
- if (current_hint_state == NULL || rel->partial_pathlist == NIL)
+ /* call the previous hook */
+ if (prev_set_rel_pathlist)
+ prev_set_rel_pathlist(root, rel, rti, rte);
+
+ /* Nothing to do when hint has not been parsed yet */
+ if (current_hint_state == NULL)
return;
- phint = find_parallel_hint(root, rel->relid, rel);
+ /* Don't touch dummy rel */
+ if (IS_DUMMY_REL(rel))
+ return;
- if (phint == NULL || !phint->force_parallel)
+ /* We cannot handle if this requires an outer */
+ if (rel->lateral_relids)
return;
- /*
- * This relation contains gather paths previously created and they prevent
- * adding new gahter path with same cost. Remove them.
- */
- oldpathlist = rel->pathlist;
- rel->pathlist = NIL;
- foreach (l, oldpathlist)
+ if (!setup_hint_enforcement(root, rel))
{
- Path *path = (Path *) lfirst(l);
+ /*
+ * No enforcement requested, but we might have to generate gather
+ * path on this relation
+ */
- if (IsA(path, GatherPath) &&
- path->parallel_workers != phint->nworkers)
+ /* If no need of a gather path, just return */
+ if (rel->reloptkind != RELOPT_BASEREL || max_hint_nworkers < 1 ||
+ rel->partial_pathlist == NIL)
+ return;
+
+ /* Lower the priorities of existing paths, then add a new path */
+ foreach (l, rel->pathlist)
{
- pfree(path);
- regenerate = true;
+ Path *path = (Path *) lfirst(l);
+
+ if (path->startup_cost < disable_cost)
+ {
+ path->startup_cost += disable_cost;
+ path->total_cost += disable_cost;
+ }
}
- else
- rel->pathlist = lappend(rel->pathlist, path);
+
+ generate_gather_paths(root, rel);
+ return;
}
- list_free(oldpathlist);
- if (regenerate)
+ /* Here, we regenerate paths with the current hint restriction */
+
+ /* Remove prviously paths except dummy rels */
+ list_free_deep(rel->pathlist);
+ rel->pathlist = NIL;
+
+ /* Rebuild access paths */
+ set_plain_rel_pathlist(root, rel, rte);
+
+ /*
+ * create_plain_partial_paths creates partial paths with reasonably
+ * estimated number of workers. Force the requested number of workers if
+ * hard mode.
+ */
+ phint = find_parallel_hint(root, rel->relid, rel);
+
+ if (phint)
{
- foreach (l, rel->partial_pathlist)
+ /* if inhibiting parallel, remove existing partial paths */
+ if (phint->nworkers == 0 && rel->partial_pathlist)
{
- Path *ppath = (Path *) lfirst(l);
-
- if (phint && phint->nworkers > 0 && phint->force_parallel)
+ list_free_deep(rel->partial_pathlist);
+ rel->partial_pathlist = NIL;
+ }
+
+ /* enforce number of workers if requested */
+ if (rel->partial_pathlist && phint->force_parallel)
+ {
+ foreach (l, rel->partial_pathlist)
{
- Assert(ppath->parallel_workers > 0);
+ Path *ppath = (Path *) lfirst(l);
+
ppath->parallel_workers = phint->nworkers;
- }
+ }
}
-
- generate_gather_paths(root, rel);
+
+ /* Generate gather paths for base rels */
+ if (rel->reloptkind == RELOPT_BASEREL)
+ generate_gather_paths(root, rel);
}
+
+ reset_hint_enforcement();
}
/*
* Build access paths for a base relation
*
* This function was copied and edited from set_rel_pathlist() in
- * src/backend/optimizer/path/allpaths.c
+ * src/backend/optimizer/path/allpaths.c in order not to copy other static
+ * functions not required here.
*/
static void
set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
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