* pg_hint_plan.c
* hinting on how to execute a query for PostgreSQL
*
- * Copyright (c) 2012-2017, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
+ * Copyright (c) 2012-2018, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
*
*-------------------------------------------------------------------------
*/
#include "mb/pg_wchar.h"
#include "miscadmin.h"
#include "nodes/nodeFuncs.h"
+#include "nodes/params.h"
#include "optimizer/clauses.h"
#include "optimizer/cost.h"
#include "optimizer/geqo.h"
#include "optimizer/planner.h"
#include "optimizer/prep.h"
#include "optimizer/restrictinfo.h"
+#include "parser/analyze.h"
#include "parser/scansup.h"
#include "tcop/utility.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/rel.h"
+#include "utils/snapmgr.h"
#include "utils/syscache.h"
#include "utils/resowner.h"
#define HINT_ARRAY_DEFAULT_INITSIZE 8
-#define hint_ereport(str, detail) \
- ereport(pg_hint_plan_message_level, \
- (errhidestmt(hidestmt), \
- errmsg("pg_hint_plan%s: hint syntax error at or near \"%s\"", qnostr, (str)), \
- errdetail detail))
+#define hint_ereport(str, detail) hint_parse_ereport(str, detail)
+#define hint_parse_ereport(str, detail) \
+ do { \
+ ereport(pg_hint_plan_parse_message_level, \
+ (errmsg("pg_hint_plan: hint syntax error at or near \"%s\"", (str)), \
+ errdetail detail)); \
+ } while(0)
#define skip_space(str) \
while (isspace(*str)) \
HINT_TYPE_PARALLEL
} HintType;
+typedef enum HintTypeBitmap
+{
+ HINT_BM_SCAN_METHOD = 1,
+ HINT_BM_PARALLEL = 2
+} HintTypeBitmap;
+
static const char *HintTypeName[] = {
"scan method",
"join method",
(hint)->base.state == HINT_STATE_USED)
static unsigned int qno = 0;
+static unsigned int msgqno = 0;
static char qnostr[32];
+static const char *current_hint_str = NULL;
+
+/*
+ * However we usually take a hint stirng in post_parse_analyze_hook, we still
+ * need to do so in planner_hook when client starts query execution from the
+ * bind message on a prepared query. This variable prevent duplicate and
+ * sometimes harmful hint string retrieval.
+ */
+static bool current_hint_retrieved = false;
/* common data for all hints. */
struct Hint
int init_paratup_cost; /* parallel_tuple_cost */
int init_parasetup_cost;/* parallel_setup_cost */
+ PlannerInfo *current_root; /* PlannerInfo for the followings */
Index parent_relid; /* inherit parent of table relid */
ScanMethodHint *parent_scan_hint; /* scan hint for the parent */
ParallelHint *parent_parallel_hint; /* parallel hint for the parent */
static void push_hint(HintState *hstate);
static void pop_hint(void);
+static void pg_hint_plan_post_parse_analyze(ParseState *pstate, Query *query);
static void pg_hint_plan_ProcessUtility(Node *parsetree,
- const char *queryString,
- ProcessUtilityContext context,
- ParamListInfo params,
- DestReceiver *dest, char *completionTag);
+ const char *queryString,
+ ProcessUtilityContext context, ParamListInfo params,
+ DestReceiver *dest, char *completionTag);
static PlannedStmt *pg_hint_plan_planner(Query *parse, int cursorOptions,
ParamListInfo boundParams);
static RelOptInfo *pg_hint_plan_join_search(PlannerInfo *root,
Index rti, RangeTblEntry *rte);
static void create_plain_partial_paths(PlannerInfo *root,
RelOptInfo *rel);
-static int compute_parallel_worker(RelOptInfo *rel, BlockNumber pages);
static void make_rels_by_clause_joins(PlannerInfo *root, RelOptInfo *old_rel,
ListCell *other_rels);
/* GUC variables */
static bool pg_hint_plan_enable_hint = true;
static int debug_level = 0;
-static int pg_hint_plan_message_level = INFO;
+static int pg_hint_plan_parse_message_level = INFO;
+static int pg_hint_plan_debug_message_level = LOG;
/* Default is off, to keep backward compatibility. */
static bool pg_hint_plan_enable_hint_table = false;
-/* Internal static variables. */
-static bool hidestmt = false; /* Allow or inhibit STATEMENT: output */
-
static int plpgsql_recurse_level = 0; /* PLpgSQL recursion level */
static int hint_inhibit_level = 0; /* Inhibit hinting if this is above 0 */
/* (This could not be above 1) */
};
/* Saved hook values in case of unload */
-static ProcessUtility_hook_type prev_ProcessUtility = NULL;
+static post_parse_analyze_hook_type prev_post_parse_analyze_hook = NULL;
static planner_hook_type prev_planner = NULL;
static join_search_hook_type prev_join_search = NULL;
static set_rel_pathlist_hook_type prev_set_rel_pathlist = NULL;
+static ProcessUtility_hook_type prev_ProcessUtility_hook = NULL;
/* Hold reference to currently active hint */
static HintState *current_hint_state = NULL;
*/
static List *HintStateStack = NIL;
-/*
- * Holds statement name during executing EXECUTE command. NULL for other
- * statements.
- */
-static char *stmt_name = NULL;
-
static const HintParser parsers[] = {
{HINT_SEQSCAN, ScanMethodHintCreate, HINT_KEYWORD_SEQSCAN},
{HINT_INDEXSCAN, ScanMethodHintCreate, HINT_KEYWORD_INDEXSCAN},
DefineCustomEnumVariable("pg_hint_plan.parse_messages",
"Message level of parse errors.",
NULL,
- &pg_hint_plan_message_level,
+ &pg_hint_plan_parse_message_level,
INFO,
parse_messages_level_options,
PGC_USERSET,
DefineCustomEnumVariable("pg_hint_plan.message_level",
"Message level of debug messages.",
NULL,
- &pg_hint_plan_message_level,
- INFO,
+ &pg_hint_plan_debug_message_level,
+ LOG,
parse_messages_level_options,
PGC_USERSET,
0,
NULL);
/* Install hooks. */
- prev_ProcessUtility = ProcessUtility_hook;
- ProcessUtility_hook = pg_hint_plan_ProcessUtility;
+ prev_post_parse_analyze_hook = post_parse_analyze_hook;
+ post_parse_analyze_hook = pg_hint_plan_post_parse_analyze;
prev_planner = planner_hook;
planner_hook = pg_hint_plan_planner;
prev_join_search = join_search_hook;
join_search_hook = pg_hint_plan_join_search;
prev_set_rel_pathlist = set_rel_pathlist_hook;
set_rel_pathlist_hook = pg_hint_plan_set_rel_pathlist;
+ prev_ProcessUtility_hook = ProcessUtility_hook;
+ ProcessUtility_hook = pg_hint_plan_ProcessUtility;
/* setup PL/pgSQL plugin hook */
var_ptr = (PLpgSQL_plugin **) find_rendezvous_variable("PLpgSQL_plugin");
PLpgSQL_plugin **var_ptr;
/* Uninstall hooks. */
- ProcessUtility_hook = prev_ProcessUtility;
+ post_parse_analyze_hook = prev_post_parse_analyze_hook;
planner_hook = prev_planner;
join_search_hook = prev_join_search;
set_rel_pathlist_hook = prev_set_rel_pathlist;
+ ProcessUtility_hook = prev_ProcessUtility_hook;
/* uninstall PL/pgSQL plugin hook */
var_ptr = (PLpgSQL_plugin **) find_rendezvous_variable("PLpgSQL_plugin");
hstate->init_min_para_size = 0;
hstate->init_paratup_cost = 0;
hstate->init_parasetup_cost = 0;
+ hstate->current_root = NULL;
hstate->parent_relid = 0;
hstate->parent_scan_hint = NULL;
hstate->parent_parallel_hint = NULL;
if (!hstate)
{
- elog(LOG, "pg_hint_plan:\nno hint");
+ elog(pg_hint_plan_debug_message_level, "pg_hint_plan:\nno hint");
return;
}
desc_hint_in_state(hstate, &buf, "duplication hint", HINT_STATE_DUPLICATION, false);
desc_hint_in_state(hstate, &buf, "error hint", HINT_STATE_ERROR, false);
- elog(LOG, "%s", buf.data);
+ ereport(pg_hint_plan_debug_message_level,
+ (errmsg ("%s", buf.data)));
pfree(buf.data);
}
if (!hstate)
{
- elog(pg_hint_plan_message_level,
+ elog(pg_hint_plan_debug_message_level,
"pg_hint_plan%s: HintStateDump: no hint", qnostr);
return;
}
desc_hint_in_state(hstate, &buf, "}, {error hints", HINT_STATE_ERROR, true);
appendStringInfoChar(&buf, '}');
- ereport(pg_hint_plan_message_level,
- (errhidestmt(true),
- errmsg("%s", buf.data)));
+ ereport(pg_hint_plan_debug_message_level,
+ (errmsg("%s", buf.data),
+ errhidestmt(true),
+ errhidecontext(true)));
pfree(buf.data);
}
char *keyword = parser->keyword;
Hint *hint;
- if (strcasecmp(buf.data, keyword) != 0)
+ if (pg_strcasecmp(buf.data, keyword) != 0)
continue;
hint = parser->create_func(head, keyword, parser->hint_keyword);
PG_TRY();
{
+ bool snapshot_set = false;
+
hint_inhibit_level++;
+
+ if (!ActiveSnapshotSet())
+ {
+ PushActiveSnapshot(GetTransactionSnapshot());
+ snapshot_set = true;
+ }
SPI_connect();
}
SPI_finish();
-
+
+ if (snapshot_set)
+ PopActiveSnapshot();
+
hint_inhibit_level--;
}
PG_CATCH();
}
/*
- * Get client-supplied query string.
+ * Get client-supplied query string. Addtion to that the jumbled query is
+ * supplied if the caller requested. From the restriction of JumbleQuery, some
+ * kind of query needs special amendments. Reutrns NULL if this query doesn't
+ * change the current hint. This function returns NULL also when something
+ * wrong has happend and let the caller continue using the current hints.
*/
static const char *
-get_query_string(void)
+get_query_string(ParseState *pstate, Query *query, Query **jumblequery)
{
- const char *p;
+ const char *p = debug_query_string;
- if (plpgsql_recurse_level > 0)
+ /*
+ * If debug_query_string is set, it is the top level statement. But in some
+ * cases we reach here with debug_query_string set NULL for example in the
+ * case of DESCRIBE message handling or EXECUTE command. We may still see a
+ * candidate top-level query in pstate in the case.
+ */
+ if (!p && pstate)
+ p = pstate->p_sourcetext;
+
+ /* We don't see a query string, return NULL */
+ if (!p)
+ return NULL;
+
+ if (jumblequery != NULL)
+ *jumblequery = query;
+
+ /* Query for DeclareCursorStmt is CMD_SELECT and has query->utilityStmt */
+ if (query->commandType == CMD_UTILITY || query->utilityStmt)
{
+ Query *target_query = query;
+
/*
- * This is quite ugly but this is the only point I could find where
- * we can get the query string.
+ * Some utility statements have a subquery that we can hint on. Since
+ * EXPLAIN can be placed before other kind of utility statements and
+ * EXECUTE can be contained other kind of utility statements, these
+ * conditions are not mutually exclusive and should be considered in
+ * this order.
*/
- p = (char*)error_context_stack->arg;
- }
- else if (stmt_name)
- {
- PreparedStatement *entry;
+ if (IsA(target_query->utilityStmt, ExplainStmt))
+ {
+ ExplainStmt *stmt = (ExplainStmt *)target_query->utilityStmt;
+
+ Assert(IsA(stmt->query, Query));
+ target_query = (Query *)stmt->query;
+
+ /* strip out the top-level query for further processing */
+ if (target_query->commandType == CMD_UTILITY &&
+ target_query->utilityStmt != NULL)
+ target_query = (Query *)target_query->utilityStmt;
+ }
+
+ /*
+ * JumbleQuery does not accept a Query that has utilityStmt. On the
+ * other hand DeclareCursorStmt is in a bit strange shape that is
+ * flipped upside down.
+ */
+ if (IsA(target_query, Query) &&
+ target_query->utilityStmt &&
+ IsA(target_query->utilityStmt, DeclareCursorStmt))
+ {
+ /*
+ * The given Query cannot be modified so copy it and modify so that
+ * JumbleQuery can accept it.
+ */
+ Assert(IsA(target_query, Query) &&
+ target_query->commandType == CMD_SELECT);
+ target_query = copyObject(target_query);
+ target_query->utilityStmt = NULL;
+ }
- entry = FetchPreparedStatement(stmt_name, true);
- p = entry->plansource->query_string;
+ if (IsA(target_query, CreateTableAsStmt))
+ {
+ CreateTableAsStmt *stmt = (CreateTableAsStmt *) target_query;
+
+ Assert(IsA(stmt->query, Query));
+ target_query = (Query *) stmt->query;
+
+ /* strip out the top-level query for further processing */
+ if (target_query->commandType == CMD_UTILITY &&
+ target_query->utilityStmt != NULL)
+ target_query = (Query *)target_query->utilityStmt;
+ }
+
+ if (IsA(target_query, ExecuteStmt))
+ {
+ /*
+ * Use the prepared query for EXECUTE. The Query for jumble
+ * also replaced with the corresponding one.
+ */
+ ExecuteStmt *stmt = (ExecuteStmt *)target_query;
+ PreparedStatement *entry;
+
+ entry = FetchPreparedStatement(stmt->name, true);
+ p = entry->plansource->query_string;
+ target_query = (Query *) linitial (entry->plansource->query_list);
+ }
+
+ /* JumbleQuery accespts only a non-utility Query */
+ if (!IsA(target_query, Query) ||
+ target_query->utilityStmt != NULL)
+ target_query = NULL;
+
+ if (jumblequery)
+ *jumblequery = target_query;
}
- else
- p = debug_query_string;
+ /*
+ * Return NULL if pstate is not of top-level query. We don't need this
+ * when jumble info is not requested or cannot do this when pstate is NULL.
+ */
+ else if (!jumblequery && pstate && pstate->p_sourcetext != p &&
+ strcmp(pstate->p_sourcetext, p) != 0)
+ p = NULL;
return p;
}
if (length < 2 || length > 3)
{
- hint_ereport(str,
- ("Wrong number of arguments for %s hint.",
- hint->base.keyword));
+ hint_ereport(")",
+ ("wrong number of arguments (%d): %s",
+ length, hint->base.keyword));
hint->base.state = HINT_STATE_ERROR;
return str;
}
/* The second parameter is number of workers */
hint->nworkers_str = list_nth(name_list, 1);
nworkers = strtod(hint->nworkers_str, &end_ptr);
- if (*end_ptr || nworkers < 0)
+ if (*end_ptr || nworkers < 0 || nworkers > max_worker_processes)
{
- hint_ereport(hint->nworkers_str,
- ("number of workers must be a positive integer: %s",
- hint->base.keyword));
+ if (*end_ptr)
+ hint_ereport(hint->nworkers_str,
+ ("number of workers must be a number: %s",
+ hint->base.keyword));
+ else if (nworkers < 0)
+ hint_ereport(hint->nworkers_str,
+ ("number of workers must be positive: %s",
+ hint->base.keyword));
+ else if (nworkers > max_worker_processes)
+ hint_ereport(hint->nworkers_str,
+ ("number of workers = %d is larger than max_worker_processes(%d): %s",
+ nworkers, max_worker_processes, hint->base.keyword));
+
hint->base.state = HINT_STATE_ERROR;
- return str;
}
hint->nworkers = nworkers;
- if (nworkers > max_hint_nworkers)
- max_hint_nworkers = nworkers;
-
/* optional third parameter is specified */
if (length == 3)
{
const char *modeparam = (const char *)list_nth(name_list, 2);
- if (strcasecmp(modeparam, "hard") == 0)
+ if (pg_strcasecmp(modeparam, "hard") == 0)
force_parallel = true;
- else if (strcasecmp(modeparam, "soft") != 0)
+ else if (pg_strcasecmp(modeparam, "soft") != 0)
{
- hint_ereport(str,
- ("The mode of Worker hint must be soft or hard."));
+ hint_ereport(modeparam,
+ ("enforcement must be soft or hard: %s",
+ hint->base.keyword));
hint->base.state = HINT_STATE_ERROR;
- return str;
}
}
-
+
hint->force_parallel = force_parallel;
+ if (hint->base.state != HINT_STATE_ERROR &&
+ nworkers > max_hint_nworkers)
+ max_hint_nworkers = nworkers;
+
return str;
}
ereport(elevel,
(errcode(errdata->sqlerrcode),
- errhidestmt(hidestmt),
errmsg("%s", errdata->message),
errdata->detail ? errdetail("%s", errdata->detail) : 0,
errdata->hint ? errhint("%s", errdata->hint) : 0));
+ msgqno = qno;
FreeErrorData(errdata);
}
PG_END_TRY();
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))));
+ ereport(pg_hint_plan_parse_message_level,
+ (errmsg ("Failed to convert integer to string: %d", value)));
return false;
}
return
set_config_option_noerror(name, buf, context,
PGC_S_SESSION, GUC_ACTION_SAVE, true,
- pg_hint_plan_message_level);
+ pg_hint_plan_parse_message_level);
}
/* setup scan method enforcement according to given options */
result = set_config_option_noerror(hint->name, hint->value, context,
PGC_S_SESSION, GUC_ACTION_SAVE, true,
- pg_hint_plan_message_level);
+ pg_hint_plan_parse_message_level);
if (result != 0)
hint->base.state = HINT_STATE_USED;
else
}
/*
- * pg_hint_plan hook functions
+ * Push a hint into hint stack which is implemented with List struct. Head of
+ * list is top of stack.
*/
-
static void
-pg_hint_plan_ProcessUtility(Node *parsetree, const char *queryString,
- ProcessUtilityContext context,
- ParamListInfo params,
- DestReceiver *dest, char *completionTag)
+push_hint(HintState *hstate)
{
- Node *node;
-
- /*
- * Use standard planner if pg_hint_plan is disabled or current nesting
- * depth is nesting depth of SPI calls.
- */
- if (!pg_hint_plan_enable_hint || hint_inhibit_level > 0)
- {
- if (debug_level > 1)
- ereport(pg_hint_plan_message_level,
- (errmsg ("pg_hint_plan: ProcessUtility:"
- " pg_hint_plan.enable_hint = off")));
- if (prev_ProcessUtility)
- (*prev_ProcessUtility) (parsetree, queryString,
- context, params,
- dest, completionTag);
- else
- standard_ProcessUtility(parsetree, queryString,
- context, params,
- dest, completionTag);
- return;
- }
-
- node = parsetree;
- if (IsA(node, ExplainStmt))
- {
- /*
- * Draw out parse tree of actual query from Query struct of EXPLAIN
- * statement.
- */
- ExplainStmt *stmt;
- Query *query;
-
- stmt = (ExplainStmt *) node;
+ /* Prepend new hint to the list means pushing to stack. */
+ HintStateStack = lcons(hstate, HintStateStack);
- Assert(IsA(stmt->query, Query));
- query = (Query *) stmt->query;
+ /* Pushed hint is the one which should be used hereafter. */
+ current_hint_state = hstate;
+}
- if (query->commandType == CMD_UTILITY && query->utilityStmt != NULL)
- node = query->utilityStmt;
- }
+/* Pop a hint from hint stack. Popped hint is automatically discarded. */
+static void
+pop_hint(void)
+{
+ /* Hint stack must not be empty. */
+ if(HintStateStack == NIL)
+ elog(ERROR, "hint stack is empty");
/*
- * If the query was a EXECUTE or CREATE TABLE AS EXECUTE, get query string
- * specified to preceding PREPARE command to use it as source of hints.
+ * Take a hint at the head from the list, and free it. Switch
+ * current_hint_state to point new head (NULL if the list is empty).
*/
- if (IsA(node, ExecuteStmt))
- {
- ExecuteStmt *stmt;
+ HintStateStack = list_delete_first(HintStateStack);
+ HintStateDelete(current_hint_state);
+ if(HintStateStack == NIL)
+ current_hint_state = NULL;
+ else
+ current_hint_state = (HintState *) lfirst(list_head(HintStateStack));
+}
- stmt = (ExecuteStmt *) node;
- stmt_name = stmt->name;
- }
+/*
+ * Retrieve and store hint string from given query or from the hint table.
+ */
+static void
+get_current_hint_string(ParseState *pstate, Query *query)
+{
+ const char *query_str;
+ MemoryContext oldcontext;
- /*
- * CREATE AS EXECUTE behavior has changed since 9.2, so we must handle it
- * specially here.
- */
- if (IsA(node, CreateTableAsStmt))
- {
- CreateTableAsStmt *stmt;
- Query *query;
+ /* do nothing under hint table search */
+ if (hint_inhibit_level > 0)
+ return;
- stmt = (CreateTableAsStmt *) node;
- Assert(IsA(stmt->query, Query));
- query = (Query *) stmt->query;
+ /* We alredy have one, don't parse it again. */
+ if (current_hint_retrieved)
+ return;
+
+ /* Don't parse the current query hereafter */
+ current_hint_retrieved = true;
- if (query->commandType == CMD_UTILITY &&
- IsA(query->utilityStmt, ExecuteStmt))
+ if (!pg_hint_plan_enable_hint)
+ {
+ if (current_hint_str)
{
- ExecuteStmt *estmt = (ExecuteStmt *) query->utilityStmt;
- stmt_name = estmt->name;
+ pfree((void *)current_hint_str);
+ current_hint_str = NULL;
}
+ return;
}
- if (stmt_name)
+ /* increment the query number */
+ qnostr[0] = 0;
+ if (debug_level > 1)
+ snprintf(qnostr, sizeof(qnostr), "[qno=0x%x]", qno++);
+ qno++;
+
+ /* search the hint table for a hint if requested */
+ if (pg_hint_plan_enable_hint_table)
{
- if (debug_level > 1)
- ereport(pg_hint_plan_message_level,
- (errmsg ("pg_hint_plan: ProcessUtility:"
- " stmt_name = \"%s\", statement=\"%s\"",
- stmt_name, queryString)));
+ int query_len;
+ pgssJumbleState jstate;
+ Query *jumblequery;
+ char *normalized_query = NULL;
- PG_TRY();
+ query_str = get_query_string(pstate, query, &jumblequery);
+
+ /* If this query is not for hint, just return */
+ if (!query_str)
+ return;
+
+ /* clear the previous hint string */
+ if (current_hint_str)
{
- if (prev_ProcessUtility)
- (*prev_ProcessUtility) (parsetree, queryString,
- context, params,
- dest, completionTag);
- else
- standard_ProcessUtility(parsetree, queryString,
- context, params,
- dest, completionTag);
+ pfree((void *)current_hint_str);
+ current_hint_str = NULL;
}
- PG_CATCH();
+
+ if (jumblequery)
{
- stmt_name = NULL;
- PG_RE_THROW();
+ /*
+ * XXX: normalization code is copied from pg_stat_statements.c.
+ * Make sure to keep up-to-date with it.
+ */
+ jstate.jumble = (unsigned char *) palloc(JUMBLE_SIZE);
+ jstate.jumble_len = 0;
+ jstate.clocations_buf_size = 32;
+ jstate.clocations = (pgssLocationLen *)
+ palloc(jstate.clocations_buf_size * sizeof(pgssLocationLen));
+ jstate.clocations_count = 0;
+
+ JumbleQuery(&jstate, jumblequery);
+
+ /*
+ * Normalize the query string by replacing constants with '?'
+ */
+ /*
+ * Search hint string which is stored keyed by query string
+ * and application name. The query string is normalized to allow
+ * fuzzy matching.
+ *
+ * Adding 1 byte to query_len ensures that the returned string has
+ * a terminating NULL.
+ */
+ query_len = strlen(query_str) + 1;
+ normalized_query =
+ generate_normalized_query(&jstate, query_str,
+ &query_len,
+ GetDatabaseEncoding());
+
+ /*
+ * find a hint for the normalized query. the result should be in
+ * TopMemoryContext
+ */
+ oldcontext = MemoryContextSwitchTo(TopMemoryContext);
+ current_hint_str =
+ get_hints_from_table(normalized_query, application_name);
+ MemoryContextSwitchTo(oldcontext);
+
+ if (debug_level > 1)
+ {
+ if (current_hint_str)
+ ereport(pg_hint_plan_debug_message_level,
+ (errmsg("pg_hint_plan[qno=0x%x]: "
+ "post_parse_analyze_hook: "
+ "hints from table: \"%s\": "
+ "normalized_query=\"%s\", "
+ "application name =\"%s\"",
+ qno, current_hint_str,
+ normalized_query, application_name),
+ errhidestmt(msgqno != qno),
+ errhidecontext(msgqno != qno)));
+ else
+ ereport(pg_hint_plan_debug_message_level,
+ (errmsg("pg_hint_plan[qno=0x%x]: "
+ "no match found in table: "
+ "application name = \"%s\", "
+ "normalized_query=\"%s\"",
+ qno, application_name,
+ normalized_query),
+ errhidestmt(msgqno != qno),
+ errhidecontext(msgqno != qno)));
+
+ msgqno = qno;
+ }
}
- PG_END_TRY();
- stmt_name = NULL;
+ /* retrun if we have hint here */
+ if (current_hint_str)
+ return;
+ }
+ else
+ query_str = get_query_string(pstate, query, NULL);
- return;
+ if (query_str)
+ {
+ /*
+ * get hints from the comment. However we may have the same query
+ * string with the previous call, but the extra comparison seems no
+ * use..
+ */
+ if (current_hint_str)
+ pfree((void *)current_hint_str);
+
+ oldcontext = MemoryContextSwitchTo(TopMemoryContext);
+ current_hint_str = get_hints_from_comment(query_str);
+ MemoryContextSwitchTo(oldcontext);
}
- if (prev_ProcessUtility)
- (*prev_ProcessUtility) (parsetree, queryString,
- context, params,
- dest, completionTag);
+ if (debug_level > 1)
+ {
+ if (debug_level == 1 && query_str && debug_query_string &&
+ strcmp(query_str, debug_query_string))
+ ereport(pg_hint_plan_debug_message_level,
+ (errmsg("hints in comment=\"%s\"",
+ current_hint_str ? current_hint_str : "(none)"),
+ errhidestmt(msgqno != qno),
+ errhidecontext(msgqno != qno)));
else
- standard_ProcessUtility(parsetree, queryString,
- context, params,
- dest, completionTag);
+ ereport(pg_hint_plan_debug_message_level,
+ (errmsg("hints in comment=\"%s\", query=\"%s\", debug_query_string=\"%s\"",
+ current_hint_str ? current_hint_str : "(none)",
+ query_str ? query_str : "(none)",
+ debug_query_string ? debug_query_string : "(none)"),
+ errhidestmt(msgqno != qno),
+ errhidecontext(msgqno != qno)));
+ msgqno = qno;
+ }
}
/*
- * Push a hint into hint stack which is implemented with List struct. Head of
- * list is top of stack.
+ * Retrieve hint string from the current query.
*/
static void
-push_hint(HintState *hstate)
+pg_hint_plan_post_parse_analyze(ParseState *pstate, Query *query)
{
- /* Prepend new hint to the list means pushing to stack. */
- HintStateStack = lcons(hstate, HintStateStack);
+ if (prev_post_parse_analyze_hook)
+ prev_post_parse_analyze_hook(pstate, query);
- /* Pushed hint is the one which should be used hereafter. */
- current_hint_state = hstate;
+ /* always retrieve hint from the top-level query string */
+ if (plpgsql_recurse_level == 0)
+ current_hint_retrieved = false;
+
+ get_current_hint_string(pstate, query);
}
-/* Pop a hint from hint stack. Popped hint is automatically discarded. */
+/*
+ * We need to reset current_hint_retrieved flag always when a command execution
+ * is finished. This is true even for a pure utility command that doesn't
+ * involve planning phase.
+ */
static void
-pop_hint(void)
+pg_hint_plan_ProcessUtility(Node *parsetree, const char *queryString,
+ ProcessUtilityContext context, ParamListInfo params,
+ DestReceiver *dest, char *completionTag)
{
- /* Hint stack must not be empty. */
- if(HintStateStack == NIL)
- elog(ERROR, "hint stack is empty");
-
- /*
- * Take a hint at the head from the list, and free it. Switch
- * current_hint_state to point new head (NULL if the list is empty).
- */
- HintStateStack = list_delete_first(HintStateStack);
- HintStateDelete(current_hint_state);
- if(HintStateStack == NIL)
- current_hint_state = NULL;
+ if (prev_ProcessUtility_hook)
+ prev_ProcessUtility_hook(parsetree, queryString, context, params,
+ dest, completionTag);
else
- current_hint_state = (HintState *) lfirst(list_head(HintStateStack));
+ standard_ProcessUtility(parsetree, queryString, context, params,
+ dest, completionTag);
+
+ if (plpgsql_recurse_level == 0)
+ current_hint_retrieved = false;
}
+/*
+ * Read and set up hint information
+ */
static PlannedStmt *
pg_hint_plan_planner(Query *parse, int cursorOptions, ParamListInfo boundParams)
{
- const char *hints = NULL;
- const char *query;
- char *norm_query;
- pgssJumbleState jstate;
- int query_len;
int save_nestlevel;
PlannedStmt *result;
HintState *hstate;
- char msgstr[1024];
-
- qnostr[0] = 0;
- strcpy(msgstr, "");
- if (debug_level > 1)
- snprintf(qnostr, sizeof(qnostr), "[qno=0x%x]", qno++);
- hidestmt = false;
/*
* Use standard planner if pg_hint_plan is disabled or current nesting
if (!pg_hint_plan_enable_hint || hint_inhibit_level > 0)
{
if (debug_level > 1)
- elog(pg_hint_plan_message_level,
- "pg_hint_plan%s: planner: enable_hint=%d,"
- " hint_inhibit_level=%d",
- qnostr, pg_hint_plan_enable_hint, hint_inhibit_level);
- hidestmt = true;
+ ereport(pg_hint_plan_debug_message_level,
+ (errmsg ("pg_hint_plan%s: planner: enable_hint=%d,"
+ " hint_inhibit_level=%d",
+ qnostr, pg_hint_plan_enable_hint,
+ hint_inhibit_level),
+ errhidestmt(msgqno != qno)));
+ msgqno = qno;
goto standard_planner_proc;
}
- /* Create hint struct from client-supplied query string. */
- query = get_query_string();
-
/*
- * Create hintstate from hint specified for the query, if any.
- *
- * First we lookup hint in pg_hint.hints table by normalized query string,
- * unless pg_hint_plan.enable_hint_table is OFF.
- * This parameter provides option to avoid overhead of table lookup during
- * planning.
- *
- * If no hint was found, then we try to get hint from special query comment.
+ * Support for nested plpgsql functions. This is quite ugly but this is the
+ * only point I could find where I can get the query string.
*/
- if (pg_hint_plan_enable_hint_table)
- {
- /*
- * Search hint information which is stored for the query and the
- * application. Query string is normalized before using in condition
- * in order to allow fuzzy matching.
- *
- * XXX: normalizing code is copied from pg_stat_statements.c, so be
- * careful when supporting PostgreSQL's version up.
- */
- jstate.jumble = (unsigned char *) palloc(JUMBLE_SIZE);
- jstate.jumble_len = 0;
- jstate.clocations_buf_size = 32;
- jstate.clocations = (pgssLocationLen *)
- palloc(jstate.clocations_buf_size * sizeof(pgssLocationLen));
- jstate.clocations_count = 0;
- JumbleQuery(&jstate, parse);
- /*
- * generate_normalized_query() copies exact given query_len bytes, so we
- * add 1 byte for null-termination here. As comments on
- * generate_normalized_query says, generate_normalized_query doesn't
- * take care of null-terminate, but additional 1 byte ensures that '\0'
- * byte in the source buffer to be copied into norm_query.
- */
- query_len = strlen(query) + 1;
- norm_query = generate_normalized_query(&jstate,
- query,
- &query_len,
- GetDatabaseEncoding());
- hints = get_hints_from_table(norm_query, application_name);
- if (debug_level > 1)
- {
- if (hints)
- snprintf(msgstr, 1024, "hints from table: \"%s\":"
- " normalzed_query=\"%s\", application name =\"%s\"",
- hints, norm_query, application_name);
- else
- {
- ereport(pg_hint_plan_message_level,
- (errhidestmt(hidestmt),
- errmsg("pg_hint_plan%s:"
- " no match found in table:"
- " application name = \"%s\","
- " normalzed_query=\"%s\"",
- qnostr, application_name, norm_query)));
- hidestmt = true;
- }
- }
- }
- if (hints == NULL)
+ if (plpgsql_recurse_level > 0)
{
- hints = get_hints_from_comment(query);
+ MemoryContext oldcontext;
- if (debug_level > 1)
- {
- snprintf(msgstr, 1024, "hints in comment=\"%s\"",
- hints ? hints : "(none)");
- if (debug_level > 2 ||
- stmt_name || strcmp(query, debug_query_string))
- snprintf(msgstr + strlen(msgstr), 1024- strlen(msgstr),
- ", stmt=\"%s\", query=\"%s\", debug_query_string=\"%s\"",
- stmt_name, query, debug_query_string);
- }
- }
+ if (current_hint_str)
+ pfree((void *)current_hint_str);
- hstate = create_hintstate(parse, hints);
+ oldcontext = MemoryContextSwitchTo(TopMemoryContext);
+ current_hint_str =
+ get_hints_from_comment((char *)error_context_stack->arg);
+ MemoryContextSwitchTo(oldcontext);
+ }
/*
- * Use standard planner if the statement has not valid hint. Other hook
- * functions try to change plan with current_hint_state if any, so set it
- * to NULL.
+ * Query execution in extended protocol can be started without the analyze
+ * phase. In the case retrieve hint string here.
*/
- if (!hstate)
+ if (!current_hint_str)
+ get_current_hint_string(NULL, parse);
+
+ /* No hint, go the normal way */
+ if (!current_hint_str)
goto standard_planner_proc;
+ /* parse the hint into hint state struct */
+ hstate = create_hintstate(parse, pstrdup(current_hint_str));
+
+ /* run standard planner if the statement has not valid hint */
+ if (!hstate)
+ goto standard_planner_proc;
+
/*
* Push new hint struct to the hint stack to disable previous hint context.
*/
if (debug_level > 1)
{
- ereport(pg_hint_plan_message_level,
- (errhidestmt(hidestmt),
- errmsg("pg_hint_plan%s: planner: %s",
- qnostr, msgstr)));
- hidestmt = true;
+ ereport(pg_hint_plan_debug_message_level,
+ (errhidestmt(msgqno != qno),
+ errmsg("pg_hint_plan%s: planner", qnostr)));
+ msgqno = qno;
}
/*
}
PG_END_TRY();
+
+ /*
+ * current_hint_str is useless after planning of the top-level query.
+ */
+ if (plpgsql_recurse_level < 1 && current_hint_str)
+ {
+ pfree((void *)current_hint_str);
+ current_hint_str = NULL;
+ current_hint_retrieved = false;
+ }
+
/* Print hint in debug mode. */
if (debug_level == 1)
HintStateDump(current_hint_state);
standard_planner_proc:
if (debug_level > 1)
{
- ereport(pg_hint_plan_message_level,
- (errhidestmt(hidestmt),
- errmsg("pg_hint_plan%s: planner: no valid hint (%s)",
- qnostr, msgstr)));
- hidestmt = true;
+ ereport(pg_hint_plan_debug_message_level,
+ (errhidestmt(msgqno != qno),
+ errmsg("pg_hint_plan%s: planner: no valid hint",
+ qnostr)));
+ msgqno = qno;
}
current_hint_state = NULL;
if (prev_planner)
/*
* Find scan method hint to be applied to the given relation
+ *
*/
static ScanMethodHint *
-find_scan_hint(PlannerInfo *root, Index relid, RelOptInfo *rel)
+find_scan_hint(PlannerInfo *root, Index relid)
{
+ RelOptInfo *rel;
RangeTblEntry *rte;
+ ScanMethodHint *real_name_hint = NULL;
+ ScanMethodHint *alias_hint = NULL;
int i;
+ /* This should not be a join rel */
+ Assert(relid > 0);
+ rel = root->simple_rel_array[relid];
+
/*
- * We don't apply scan method hint if the relation is:
- * - not a base relation
- * - not an ordinary relation (such as join and subquery)
+ * This function is called for any RelOptInfo or its inheritance parent if
+ * any. If we are called from inheritance planner, the RelOptInfo for the
+ * parent of target child relation is not set in the planner info.
+ *
+ * Otherwise we should check that the reloptinfo is base relation or
+ * inheritance children.
*/
- if (rel && (rel->reloptkind != RELOPT_BASEREL ||
- rel->rtekind != RTE_RELATION))
+ if (rel &&
+ rel->reloptkind != RELOPT_BASEREL &&
+ rel->reloptkind != RELOPT_OTHER_MEMBER_REL)
return NULL;
+ /*
+ * This is baserel or appendrel children. We can refer to RangeTblEntry.
+ */
rte = root->simple_rte_array[relid];
+ Assert(rte);
- /* We don't force scan method of foreign tables */
- if (rte->relkind == RELKIND_FOREIGN_TABLE)
+ /* We don't hint on other than relation and foreign tables */
+ if (rte->rtekind != RTE_RELATION ||
+ rte->relkind == RELKIND_FOREIGN_TABLE)
return NULL;
/* Find scan method hint, which matches given names, from the list. */
if (!hint_state_enabled(hint))
continue;
- if (RelnameCmp(&rte->eref->aliasname, &hint->relname) == 0)
- return hint;
+ if (!alias_hint &&
+ RelnameCmp(&rte->eref->aliasname, &hint->relname) == 0)
+ alias_hint = hint;
+
+ /* check the real name for appendrel children */
+ if (!real_name_hint &&
+ rel && rel->reloptkind == RELOPT_OTHER_MEMBER_REL)
+ {
+ char *realname = get_rel_name(rte->relid);
+
+ if (realname && RelnameCmp(&realname, &hint->relname) == 0)
+ real_name_hint = hint;
+ }
+
+ /* No more match expected, break */
+ if(alias_hint && real_name_hint)
+ break;
}
- return NULL;
+ /* real name match precedes alias match */
+ if (real_name_hint)
+ return real_name_hint;
+
+ return alias_hint;
}
static ParallelHint *
-find_parallel_hint(PlannerInfo *root, Index relid, RelOptInfo *rel)
+find_parallel_hint(PlannerInfo *root, Index relid)
{
+ RelOptInfo *rel;
RangeTblEntry *rte;
+ ParallelHint *real_name_hint = NULL;
+ ParallelHint *alias_hint = NULL;
int i;
+ /* This should not be a join rel */
+ Assert(relid > 0);
+ rel = root->simple_rel_array[relid];
+
/*
- * We don't apply scan method hint if the relation is:
- * - not a base relation and inheritance children
- * - not an ordinary relation (such as join and subquery)
+ * Parallel planning is appliable only on base relation, which has
+ * RelOptInfo.
*/
- if (!rel || rel->rtekind != RTE_RELATION ||
- (rel->reloptkind != RELOPT_BASEREL &&
- rel->reloptkind != RELOPT_OTHER_MEMBER_REL))
+ if (!rel)
return NULL;
- rte = root->simple_rte_array[relid];
-
- /* We can't force scan method of foreign tables */
- if (rte->relkind == RELKIND_FOREIGN_TABLE)
+ /*
+ * We have set root->glob->parallelModeOK if needed. What we should do here
+ * is just following the decision of planner.
+ */
+ if (!rel->consider_parallel)
return NULL;
- /* Find scan method hint, which matches given names, from the list. */
+ /*
+ * This is baserel or appendrel children. We can refer to RangeTblEntry.
+ */
+ rte = root->simple_rte_array[relid];
+ Assert(rte);
+
+ /* Find parallel method hint, which matches given names, from the list. */
for (i = 0; i < current_hint_state->num_hints[HINT_TYPE_PARALLEL]; i++)
{
ParallelHint *hint = current_hint_state->parallel_hints[i];
if (!hint_state_enabled(hint))
continue;
- if (RelnameCmp(&rte->eref->aliasname, &hint->relname) == 0)
- return hint;
+ if (!alias_hint &&
+ RelnameCmp(&rte->eref->aliasname, &hint->relname) == 0)
+ alias_hint = hint;
+
+ /* check the real name for appendrel children */
+ if (!real_name_hint &&
+ rel && rel->reloptkind == RELOPT_OTHER_MEMBER_REL)
+ {
+ char *realname = get_rel_name(rte->relid);
+
+ if (realname && RelnameCmp(&realname, &hint->relname) == 0)
+ real_name_hint = hint;
+ }
+
+ /* No more match expected, break */
+ if(alias_hint && real_name_hint)
+ break;
}
- return NULL;
+ /* real name match precedes alias match */
+ if (real_name_hint)
+ return real_name_hint;
+
+ return alias_hint;
}
/*
initStringInfo(&rel_buf);
quote_value(&rel_buf, disprelname);
- ereport(LOG,
+ ereport(pg_hint_plan_debug_message_level,
(errmsg("available indexes for %s(%s):%s",
hint->base.keyword,
rel_buf.data,
}
/*
- * Set planner guc parameters according to corresponding scan hints.
+ * Set planner guc parameters according to corresponding scan hints. Returns
+ * bitmap of HintTypeBitmap. If shint or phint is not NULL, set used hint
+ * there respectively.
*/
static bool
-setup_hint_enforcement(PlannerInfo *root, RelOptInfo *rel)
+setup_hint_enforcement(PlannerInfo *root, RelOptInfo *rel,
+ ScanMethodHint **rshint, ParallelHint **rphint)
{
Index new_parent_relid = 0;
ListCell *l;
ParallelHint *phint = NULL;
bool inhparent = root->simple_rte_array[rel->relid]->inh;
Oid relationObjectId = root->simple_rte_array[rel->relid]->relid;
+ int ret = 0;
+
+ /* reset returns if requested */
+ if (rshint != NULL) *rshint = NULL;
+ if (rphint != NULL) *rphint = NULL;
/*
* We could register the parent relation of the following children here
if (inhparent)
{
if (debug_level > 1)
- ereport(pg_hint_plan_message_level,
+ ereport(pg_hint_plan_debug_message_level,
(errhidestmt(true),
errmsg ("pg_hint_plan%s: setup_hint_enforcement"
" skipping inh parent: relation=%u(%s), inhparent=%d,"
qnostr, relationObjectId,
get_rel_name(relationObjectId),
inhparent, current_hint_state, hint_inhibit_level)));
- return false;
+ return 0;
}
+ /* Forget about the parent of another subquery */
+ if (root != current_hint_state->current_root)
+ current_hint_state->parent_relid = 0;
+
/* Find the parent for this relation other than the registered parent */
foreach (l, root->append_rel_list)
{
if (appinfo->child_relid == rel->relid)
{
if (current_hint_state->parent_relid != appinfo->parent_relid)
+ {
new_parent_relid = appinfo->parent_relid;
+ current_hint_state->current_root = root;
+ }
break;
}
}
/* Find hints for the parent */
current_hint_state->parent_scan_hint =
- find_scan_hint(root, current_hint_state->parent_relid, NULL);
+ find_scan_hint(root, current_hint_state->parent_relid);
current_hint_state->parent_parallel_hint =
- find_parallel_hint(root, current_hint_state->parent_relid, NULL);
+ find_parallel_hint(root, current_hint_state->parent_relid);
/*
* If hint is found for the parent, apply it for this child instead
}
}
- if (current_hint_state->parent_scan_hint)
+ shint = find_scan_hint(root, rel->relid);
+ if (!shint)
shint = current_hint_state->parent_scan_hint;
- else
- shint = find_scan_hint(root, rel->relid, rel);
if (shint)
{
bool using_parent_hint =
(shint == current_hint_state->parent_scan_hint);
+ ret |= HINT_BM_SCAN_METHOD;
+
/* Setup scan enforcement environment */
setup_scan_method_enforcement(shint, current_hint_state);
if (shint == current_hint_state->parent_scan_hint)
additional_message = " by parent hint";
- ereport(pg_hint_plan_message_level,
+ ereport(pg_hint_plan_debug_message_level,
(errhidestmt(true),
errmsg ("pg_hint_plan%s: setup_hint_enforcement"
" index deletion%s:"
}
/* Do the same for parallel plan enforcement */
- if (current_hint_state->parent_parallel_hint)
+ phint = find_parallel_hint(root, rel->relid);
+ if (!phint)
phint = current_hint_state->parent_parallel_hint;
- else
- phint = find_parallel_hint(root, rel->relid, rel);
setup_parallel_plan_enforcement(phint, current_hint_state);
+ if (phint)
+ ret |= HINT_BM_PARALLEL;
+
/* Nothing to apply. Reset the scan mask to intial state */
if (!shint && ! phint)
{
if (debug_level > 1)
- ereport(pg_hint_plan_message_level,
+ ereport(pg_hint_plan_debug_message_level,
(errhidestmt (true),
- errmsg ("pg_hint_plan%s: get_relation_info"
+ errmsg ("pg_hint_plan%s: setup_hint_enforcement"
" no hint applied:"
" relation=%u(%s), inhparent=%d, current_hint=%p,"
" hint_inhibit_level=%d, scanmask=0x%x",
setup_scan_method_enforcement(NULL, current_hint_state);
- return false;
+ return ret;
}
- return true;
+ if (rshint != NULL) *rshint = shint;
+ if (rphint != NULL) *rphint = phint;
+
+ return ret;
}
/*
SpecialJoinInfo *sjinfo,
List *restrictlist)
{
- ScanMethodHint *scan_hint = NULL;
Relids joinrelids;
JoinMethodHint *join_hint;
int save_nestlevel;
- if ((scan_hint = find_scan_hint(root, innerrel->relid, innerrel)) != NULL)
- setup_scan_method_enforcement(scan_hint, current_hint_state);
-
joinrelids = bms_union(outerrel->relids, innerrel->relids);
join_hint = find_join_hint(joinrelids);
bms_free(joinrelids);
else
add_paths_to_joinrel(root, joinrel, outerrel, innerrel, jointype,
sjinfo, restrictlist);
-
- /* Reset the environment if changed */
- if (scan_hint != NULL)
- setup_scan_method_enforcement(NULL, current_hint_state);
}
static int
{
ParallelHint *phint;
ListCell *l;
+ int found_hints;
/* 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 */
+ /* Nothing to do if no hint available */
if (current_hint_state == NULL)
return;
- /* Don't touch dummy rel */
+ /* Don't touch dummy rels. */
if (IS_DUMMY_REL(rel))
return;
+ /*
+ * We can accept only plain relations, foreign tables and table saples are
+ * also unacceptable. See set_rel_pathlist.
+ */
+ if (rel->rtekind != RTE_RELATION ||
+ rte->relkind == RELKIND_FOREIGN_TABLE ||
+ rte->tablesample != NULL)
+ return;
+
/* We cannot handle if this requires an outer */
if (rel->lateral_relids)
return;
- if (!setup_hint_enforcement(root, rel))
+ /* Return if this relation gets no enfocement */
+ if ((found_hints = setup_hint_enforcement(root, rel, NULL, &phint)) == 0)
+ return;
+
+ /* Here, we regenerate paths with the current hint restriction */
+
+ if (found_hints & HINT_BM_SCAN_METHOD)
{
/*
- * No enforcement requested, but we might have to generate gather
- * path on this relation
+ * With scan hints, we regenerate paths for this relation from the
+ * first under the restricion.
*/
+ list_free_deep(rel->pathlist);
+ rel->pathlist = NIL;
- /* If no need of a gather path, just return */
- if (rel->reloptkind != RELOPT_BASEREL || max_hint_nworkers < 1 ||
- rel->partial_pathlist == NIL)
- return;
+ set_plain_rel_pathlist(root, rel, rte);
+ }
+
+ if (found_hints & HINT_BM_PARALLEL)
+ {
+ Assert (phint);
+
+ /* the partial_pathlist may be for different parameters, discard it */
+ if (rel->partial_pathlist)
+ {
+ list_free_deep(rel->partial_pathlist);
+ rel->partial_pathlist = NIL;
+ }
- /* Lower the priorities of existing paths, then add a new path */
- foreach (l, rel->pathlist)
+ /* also remove gather path */
+ if (rel->pathlist)
{
- Path *path = (Path *) lfirst(l);
+ ListCell *cell, *prev = NULL, *next;
- if (path->startup_cost < disable_cost)
+ for (cell = list_head(rel->pathlist) ; cell; cell = next)
{
- path->startup_cost += disable_cost;
- path->total_cost += disable_cost;
+ Path *path = (Path *) lfirst(cell);
+
+ next = lnext(cell);
+ if (IsA(path, GatherPath))
+ rel->pathlist = list_delete_cell(rel->pathlist,
+ cell, prev);
+ else
+ prev = cell;
}
}
- generate_gather_paths(root, rel);
- return;
- }
-
- /* 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);
+ /* then generate new paths if needed */
+ if (phint->nworkers > 0)
+ {
+ /* Lower the priorities of non-parallel paths */
+ foreach (l, rel->pathlist)
+ {
+ Path *path = (Path *) lfirst(l);
- /*
- * 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 (path->startup_cost < disable_cost)
+ {
+ path->startup_cost += disable_cost;
+ path->total_cost += disable_cost;
+ }
+ }
- if (phint)
- {
- /* if inhibiting parallel, remove existing partial paths */
- if (phint->nworkers == 0 && rel->partial_pathlist)
- {
- list_free_deep(rel->partial_pathlist);
- rel->partial_pathlist = NIL;
- }
+ /*
+ * generate partial paths with enforcement, this is affected by
+ * scan method enforcement. Specifically, the cost of this partial
+ * seqscan path will be disabled_cost if seqscan is inhibited by
+ * hint or GUC parameters.
+ */
+ Assert (rel->partial_pathlist == NIL);
+ create_plain_partial_paths(root, rel);
- /* enforce number of workers if requested */
- if (rel->partial_pathlist && phint->force_parallel)
- {
- foreach (l, rel->partial_pathlist)
+ /* enforce number of workers if requested */
+ if (phint->force_parallel)
{
- Path *ppath = (Path *) lfirst(l);
+ foreach (l, rel->partial_pathlist)
+ {
+ Path *ppath = (Path *) lfirst(l);
- ppath->parallel_workers = phint->nworkers;
+ ppath->parallel_workers = phint->nworkers;
+ }
}
- }
- /* Generate gather paths for base rels */
- if (rel->reloptkind == RELOPT_BASEREL)
- generate_gather_paths(root, rel);
+ /* Generate gather paths for base rels */
+ if (rel->reloptkind == RELOPT_BASEREL)
+ generate_gather_paths(root, rel);
+ }
}
reset_hint_enforcement();
bool isTopLevel,
void *arg)
{
- if (phase != RESOURCE_RELEASE_AFTER_LOCKS)
+ if (!isTopLevel || phase != RESOURCE_RELEASE_AFTER_LOCKS)
return;
/* Cancel plpgsql nest level*/
plpgsql_recurse_level = 0;