* 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
*
*-------------------------------------------------------------------------
*/
#define HINT_ARRAY_DEFAULT_INITSIZE 8
-#define hint_ereport(str, detail) \
+#define hint_ereport(str, detail) hint_parse_ereport(str, detail)
+#define hint_parse_ereport(str, detail) \
do { \
- ereport(pg_hint_plan_message_level, \
- (errmsg("pg_hint_plan%s: hint syntax error at or near \"%s\"", qnostr, (str)), \
+ ereport(pg_hint_plan_parse_message_level, \
+ (errmsg("pg_hint_plan: hint syntax error at or near \"%s\"", (str)), \
errdetail detail)); \
- msgqno = qno; \
} while(0)
#define skip_space(str) \
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 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);
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;
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,
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");
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,
+ ereport(pg_hint_plan_debug_message_level,
(errmsg("%s", buf.data),
errhidestmt(true),
errhidecontext(true)));
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);
/*
* 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 the current hint
- * string is still valid.
+ * 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(ParseState *pstate, Query *query, Query **jumblequery)
{
const char *p = debug_query_string;
+ /*
+ * 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;
- Assert(plpgsql_recurse_level == 0);
-
- if (query->commandType == CMD_UTILITY)
+ /* Query for DeclareCursorStmt is CMD_SELECT and has query->utilityStmt */
+ if (query->commandType == CMD_UTILITY || query->utilityStmt)
{
Query *target_query = query;
- /* Use the target query if EXPLAIN */
- if (IsA(query->utilityStmt, ExplainStmt))
+ /*
+ * 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.
+ */
+ if (IsA(target_query->utilityStmt, ExplainStmt))
{
- ExplainStmt *stmt = (ExplainStmt *)(query->utilityStmt);
+ 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;
-
- if (jumblequery)
- *jumblequery = target_query;
}
- if (IsA(target_query, CreateTableAsStmt))
+ /*
+ * 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))
{
/*
- * Use the the body query for CREATE AS. The Query for jumble also
- * replaced with the corresponding one.
+ * 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;
+ }
+
+ if (IsA(target_query, CreateTableAsStmt))
+ {
CreateTableAsStmt *stmt = (CreateTableAsStmt *) target_query;
- PreparedStatement *entry;
- Query *ent_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 &&
- IsA(target_query->utilityStmt, ExecuteStmt))
- {
- ExecuteStmt *estmt = (ExecuteStmt *) target_query->utilityStmt;
- entry = FetchPreparedStatement(estmt->name, true);
- p = entry->plansource->query_string;
- ent_query = (Query *) linitial (entry->plansource->query_list);
- Assert(IsA(ent_query, Query));
- if (jumblequery)
- *jumblequery = ent_query;
- }
+ target_query->utilityStmt != NULL)
+ target_query = (Query *)target_query->utilityStmt;
}
- else
+
if (IsA(target_query, ExecuteStmt))
{
/*
- * Use the prepared query for EXECUTE. The Query for jumble also
- * replaced with the corresponding one.
+ * Use the prepared query for EXECUTE. The Query for jumble
+ * also replaced with the corresponding one.
*/
ExecuteStmt *stmt = (ExecuteStmt *)target_query;
PreparedStatement *entry;
- Query *ent_query;
entry = FetchPreparedStatement(stmt->name, true);
p = entry->plansource->query_string;
- ent_query = (Query *) linitial (entry->plansource->query_list);
- Assert(IsA(ent_query, Query));
- if (jumblequery)
- *jumblequery = ent_query;
+ 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;
}
- /* 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;
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(modeparam,
("enforcement must be soft or hard: %s",
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
}
/*
- * 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;
if (debug_level > 1)
{
if (current_hint_str)
- ereport(pg_hint_plan_message_level,
+ ereport(pg_hint_plan_debug_message_level,
(errmsg("pg_hint_plan[qno=0x%x]: "
"post_parse_analyze_hook: "
"hints from table: \"%s\": "
errhidestmt(msgqno != qno),
errhidecontext(msgqno != qno)));
else
- ereport(pg_hint_plan_message_level,
+ ereport(pg_hint_plan_debug_message_level,
(errmsg("pg_hint_plan[qno=0x%x]: "
"no match found in table: "
"application name = \"%s\", "
}
}
- /* retrun if we have hint here*/
+ /* retrun if we have hint here */
if (current_hint_str)
return;
}
{
/*
* 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);
if (debug_level > 1)
{
- if (debug_level == 1 &&
- (stmt_name || strcmp(query_str, debug_query_string)))
- ereport(pg_hint_plan_message_level,
+ 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
- ereport(pg_hint_plan_message_level,
- (errmsg("hints in comment=\"%s\", stmt=\"%s\", query=\"%s\", debug_query_string=\"%s\"",
+ 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)",
- 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(Node *parsetree, const char *queryString,
+ ProcessUtilityContext context, ParamListInfo params,
+ DestReceiver *dest, char *completionTag)
+{
+ if (prev_ProcessUtility_hook)
+ prev_ProcessUtility_hook(parsetree, queryString, context, params,
+ dest, completionTag);
+ else
+ 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 *
if (!pg_hint_plan_enable_hint || hint_inhibit_level > 0)
{
if (debug_level > 1)
- ereport(pg_hint_plan_message_level,
+ 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,
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;
if (debug_level > 1)
{
- ereport(pg_hint_plan_message_level,
+ 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,
+ ereport(pg_hint_plan_debug_message_level,
(errhidestmt(msgqno != qno),
errmsg("pg_hint_plan%s: planner: no valid hint",
qnostr)));
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,
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,"
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;
}
}
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:"
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: setup_hint_enforcement"
" no hint applied:"
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;