* pg_hint_plan.c
* hinting on how to execute a query for PostgreSQL
*
- * Copyright (c) 2012-2017, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
+ * Copyright (c) 2012-2020, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
*
*-------------------------------------------------------------------------
*/
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_min_para_tablescan_size;
/* min_parallel_index_scan_size*/
int init_min_para_indexscan_size;
- int init_paratup_cost; /* parallel_tuple_cost */
- int init_parasetup_cost;/* parallel_setup_cost */
+ double init_paratup_cost; /* parallel_tuple_cost */
+ double init_parasetup_cost;/* parallel_setup_cost */
PlannerInfo *current_root; /* PlannerInfo for the followings */
Index parent_relid; /* inherit parent of table relid */
static void pop_hint(void);
static void pg_hint_plan_post_parse_analyze(ParseState *pstate, Query *query);
+static void pg_hint_plan_ProcessUtility(PlannedStmt *pstmt,
+ const char *queryString,
+ ProcessUtilityContext context,
+ ParamListInfo params, QueryEnvironment *queryEnv,
+ 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,
HintState *state);
static int set_config_int32_option(const char *name, int32 value,
GucContext context);
+static int set_config_double_option(const char *name, double value,
+ GucContext context);
/* GUC variables */
static bool pg_hint_plan_enable_hint = true;
static bool pg_hint_plan_enable_hint_table = false;
static int plpgsql_recurse_level = 0; /* PLpgSQL recursion level */
+static int recurse_level = 0; /* recursion level incl. direct SPI calls */
static int hint_inhibit_level = 0; /* Inhibit hinting if this is above 0 */
/* (This could not be above 1) */
static int max_hint_nworkers = -1; /* Maximum nworkers of Workers hints */
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},
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");
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");
{
ParallelHint *hint;
- hint = palloc(sizeof(ScanMethodHint));
+ hint = palloc(sizeof(ParallelHint));
hint->base.hint_str = hint_str;
hint->base.keyword = keyword;
hint->base.hint_keyword = hint_keyword;
quote_value(buf, hint->relnames[i]);
}
}
- appendStringInfo(buf, " %s", hint->rows_str);
+ if (hint->rows_str != NULL)
+ appendStringInfo(buf, " %s", hint->rows_str);
appendStringInfoString(buf, ")");
if (!nolf)
appendStringInfoChar(buf, '\n');
/*
* 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. We may still see a candidate
- * top-level query in pstate in the case.
+ * case of DESCRIBE message handling or EXECUTE command. We may still see a
+ * candidate top-level query in pstate in the case.
*/
- if (!p)
- {
- /* We don't see a query string, return NULL */
- if (!pstate->p_sourcetext)
- return NULL;
-
+ if (pstate && pstate->p_sourcetext)
p = pstate->p_sourcetext;
- }
+
+ /* We don't see a query string, return NULL */
+ if (!p)
+ return NULL;
if (jumblequery != NULL)
*jumblequery = query;
PreparedStatement *entry;
entry = FetchPreparedStatement(stmt->name, true);
- p = entry->plansource->query_string;
- target_query = (Query *) linitial (entry->plansource->query_list);
+
+ if (entry->plansource->is_valid)
+ {
+ p = entry->plansource->query_string;
+ target_query = (Query *) linitial (entry->plansource->query_list);
+ }
+ else
+ {
+ /* igonre the hint for EXECUTE if invalidated */
+ p = NULL;
+ target_query = NULL;
+ }
}
/* JumbleQuery accespts only a non-utility Query */
- if (!IsA(target_query, Query) ||
- target_query->utilityStmt != NULL)
+ if (target_query &&
+ (!IsA(target_query, Query) ||
+ target_query->utilityStmt != NULL))
target_query = NULL;
if (jumblequery)
*jumblequery = target_query;
}
- /* Return NULL if the pstate is not identical to the top-level query */
- else if (strcmp(pstate->p_sourcetext, p) != 0)
+ /*
+ * 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;
List *name_list = NIL;
char *rows_str;
char *end_ptr;
+ ListCell *l;
+ int i = 0;
if ((str = parse_parentheses(str, &name_list, hint_keyword)) == NULL)
return NULL;
/* Last element must be rows specification */
hint->nrels = list_length(name_list) - 1;
- if (hint->nrels > 0)
+ if (hint->nrels < 1)
{
- ListCell *l;
- int i = 0;
+ hint_ereport(str,
+ ("%s hint needs at least one relation followed by one correction term.",
+ hint->base.keyword));
+ hint->base.state = HINT_STATE_ERROR;
- /*
- * Transform relation names from list to array to sort them with qsort
- * after.
- */
- hint->relnames = palloc(sizeof(char *) * hint->nrels);
- foreach (l, name_list)
- {
- if (hint->nrels <= i)
- break;
- hint->relnames[i] = lfirst(l);
- i++;
- }
+ return str;
+ }
+
+
+ /*
+ * Transform relation names from list to array to sort them with qsort
+ * after.
+ */
+ hint->relnames = palloc(sizeof(char *) * hint->nrels);
+ foreach (l, name_list)
+ {
+ if (hint->nrels <= i)
+ break;
+ hint->relnames[i] = lfirst(l);
+ i++;
}
/* Retieve rows estimation */
pg_hint_plan_parse_message_level);
}
+/*
+ * Sets GUC parameter of double type without throwing exceptions. Returns false
+ * if something wrong.
+ */
+static int
+set_config_double_option(const char *name, double value, GucContext context)
+{
+ char *buf = float8out_internal(value);
+ int result;
+
+ result = set_config_option_noerror(name, buf, context,
+ PGC_S_SESSION, GUC_ACTION_SAVE, true,
+ pg_hint_plan_parse_message_level);
+ pfree(buf);
+ return result;
+}
+
/* setup scan method enforcement according to given options */
static void
setup_guc_enforcement(SetHint **options, int noptions, GucContext context)
/* force means that enforce parallel as far as possible */
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);
+ set_config_double_option("parallel_tuple_cost", 0.0, state->context);
+ set_config_double_option("parallel_setup_cost", 0.0, state->context);
set_config_int32_option("min_parallel_table_scan_size", 0,
state->context);
set_config_int32_option("min_parallel_index_scan_size", 0,
}
else
{
- set_config_int32_option("parallel_tuple_cost",
+ set_config_double_option("parallel_tuple_cost",
state->init_paratup_cost, state->context);
- set_config_int32_option("parallel_setup_cost",
+ set_config_double_option("parallel_setup_cost",
state->init_parasetup_cost, state->context);
set_config_int32_option("min_parallel_table_scan_size",
state->init_min_para_tablescan_size,
}
/*
- * Retrieve and store a hint string from given query or from the hint table.
- * If we are using the hint table, the query string is needed to be normalized.
- * However, ParseState, which is not available in planner_hook, is required to
- * check if the query tree (Query) is surely corresponding to the target query.
+ * Retrieve and store hint string from given query or from the hint table.
*/
static void
-pg_hint_plan_post_parse_analyze(ParseState *pstate, Query *query)
+get_current_hint_string(ParseState *pstate, Query *query)
{
const char *query_str;
MemoryContext oldcontext;
- if (prev_post_parse_analyze_hook)
- prev_post_parse_analyze_hook(pstate, query);
-
/* do nothing under hint table search */
if (hint_inhibit_level > 0)
return;
+ /* 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 (!pg_hint_plan_enable_hint)
{
if (current_hint_str)
if (jumblequery)
{
/*
- * XXX: normalizing code is copied from pg_stat_statements.c, so be
- * careful to PostgreSQL's version up.
+ * 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;
*/
query_len = strlen(query_str) + 1;
normalized_query =
- generate_normalized_query(&jstate, query_str,
- query->stmt_location,
- &query_len,
+ generate_normalized_query(&jstate, query_str, 0, &query_len,
GetDatabaseEncoding());
/*
{
/*
* get hints from the comment. However we may have the same query
- * string with the previous call, but just retrieving hints is expected
- * to be faster than checking for identicalness before retrieval.
+ * string with the previous call, but the extra comparison seems no
+ * use..
*/
if (current_hint_str)
pfree((void *)current_hint_str);
current_hint_str = get_hints_from_comment(query_str);
MemoryContextSwitchTo(oldcontext);
}
+ else
+ {
+ /*
+ * Failed to get query. We would be in fetching invalidated
+ * plancache. Try the next chance.
+ */
+ current_hint_retrieved = false;
+ }
if (debug_level > 1)
{
- if (debug_level == 1 &&
- (stmt_name || strcmp(query_str, debug_query_string)))
+ 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)"),
errhidecontext(msgqno != qno)));
else
ereport(pg_hint_plan_debug_message_level,
- (errmsg("hints in comment=\"%s\", stmt=\"%s\", query=\"%s\", debug_query_string=\"%s\"",
+ (errmsg("hints in comment=\"%s\", query=\"%s\", debug_query_string=\"%s\"",
current_hint_str ? current_hint_str : "(none)",
- stmt_name, query_str, debug_query_string),
+ query_str ? query_str : "(none)",
+ debug_query_string ? debug_query_string : "(none)"),
errhidestmt(msgqno != qno),
errhidecontext(msgqno != qno)));
msgqno = qno;
}
/*
+ * Retrieve hint string from the current query.
+ */
+static void
+pg_hint_plan_post_parse_analyze(ParseState *pstate, Query *query)
+{
+ if (prev_post_parse_analyze_hook)
+ prev_post_parse_analyze_hook(pstate, query);
+
+ /* always retrieve hint from the top-level query string */
+ if (plpgsql_recurse_level == 0)
+ current_hint_retrieved = false;
+
+ get_current_hint_string(pstate, query);
+}
+
+/*
+ * 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
+pg_hint_plan_ProcessUtility(PlannedStmt *pstmt, const char *queryString,
+ ProcessUtilityContext context,
+ ParamListInfo params, QueryEnvironment *queryEnv,
+ DestReceiver *dest, char *completionTag)
+{
+ if (prev_ProcessUtility_hook)
+ prev_ProcessUtility_hook(pstmt, queryString, context, params, queryEnv,
+ dest, completionTag);
+ else
+ standard_ProcessUtility(pstmt, queryString, context, params, queryEnv,
+ dest, completionTag);
+
+ if (plpgsql_recurse_level == 0)
+ current_hint_retrieved = false;
+}
+
+/*
* Read and set up hint information
*/
static PlannedStmt *
int save_nestlevel;
PlannedStmt *result;
HintState *hstate;
+ const char *prev_hint_str = NULL;
/*
* Use standard planner if pg_hint_plan is disabled or current nesting
* 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 (plpgsql_recurse_level > 0)
+ if (plpgsql_recurse_level > 0 &&
+ error_context_stack && error_context_stack->arg)
{
MemoryContext oldcontext;
- if (current_hint_str)
- pfree((void *)current_hint_str);
-
oldcontext = MemoryContextSwitchTo(TopMemoryContext);
current_hint_str =
get_hints_from_comment((char *)error_context_stack->arg);
MemoryContextSwitchTo(oldcontext);
}
+ /*
+ * Query execution in extended protocol can be started without the analyze
+ * phase. In the case retrieve hint string here.
+ */
+ if (!current_hint_str)
+ get_current_hint_string(NULL, parse);
+
+ /* No hint, go the normal way */
if (!current_hint_str)
goto standard_planner_proc;
}
/*
+ * The planner call below may replace current_hint_str. Store and restore
+ * it so that the subsequent planning in the upper level doesn't get
+ * confused.
+ */
+ recurse_level++;
+ prev_hint_str = current_hint_str;
+ current_hint_str = NULL;
+
+ /*
* Use PG_TRY mechanism to recover GUC parameters and current_hint_state to
* the state when this planner started when error occurred in planner.
*/
result = (*prev_planner) (parse, cursorOptions, boundParams);
else
result = standard_planner(parse, cursorOptions, boundParams);
+
+ current_hint_str = prev_hint_str;
+ recurse_level--;
}
PG_CATCH();
{
* Rollback changes of GUC parameters, and pop current hint context
* from hint stack to rewind the state.
*/
+ current_hint_str = prev_hint_str;
+ recurse_level--;
AtEOXact_GUC(true, save_nestlevel);
pop_hint();
PG_RE_THROW();
}
PG_END_TRY();
+
+ /*
+ * current_hint_str is useless after planning of the top-level query.
+ */
+ if (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);
}
current_hint_state = NULL;
if (prev_planner)
- return (*prev_planner) (parse, cursorOptions, boundParams);
+ result = (*prev_planner) (parse, cursorOptions, boundParams);
else
- return standard_planner(parse, cursorOptions, boundParams);
+ result = standard_planner(parse, cursorOptions, boundParams);
+
+ /* The upper-level planner still needs the current hint state */
+ if (HintStateStack != NIL)
+ current_hint_state = (HintState *) lfirst(list_head(HintStateStack));
+
+ return result;
}
/*
list_free_deep(rel->pathlist);
rel->pathlist = NIL;
- /* Remove all the partial paths if Parallel hint is specfied */
- if ((found_hints & HINT_BM_PARALLEL) && rel->partial_pathlist)
- {
- list_free_deep(rel->partial_pathlist);
- rel->partial_pathlist = NIL;
- }
+ list_free_deep(rel->partial_pathlist);
+ rel->partial_pathlist = NIL;
/* Regenerate paths with the current enforcement */
set_plain_rel_pathlist(root, rel, rte);
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