* do instructions or hints to the planner using C-style block comments
* of the SQL.
*
- * Copyright (c) 2012-2014, NIPPON TELEGRAPH AND TELEPHONE CORPORATION
+ * Copyright (c) 2012-2019, 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
{
/* for scan method hints */
ScanMethodHint **scan_hints; /* parsed scan hints */
int init_scan_mask; /* initial value scan parameter */
+ PlannerInfo *current_root; /* PlannerInfo for the followings */
Index parent_relid; /* inherit parent table relid */
ScanMethodHint *parent_hint; /* inherit parent table scan hint */
List *parent_index_infos; /* information of inherit parent table's
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 void pg_hint_plan_get_relation_info(PlannerInfo *root,
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 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 ProcessUtility_hook_type prev_ProcessUtility_hook = NULL;
/* Hold reference to currently active hint */
static HintState *current_hint = 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},
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_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;
get_relation_info_hook = prev_get_relation_info;
join_search_hook = prev_join_search;
+ ProcessUtility_hook = prev_ProcessUtility_hook;
/* uninstall PL/pgSQL plugin hook */
var_ptr = (PLpgSQL_plugin **) find_rendezvous_variable("PLpgSQL_plugin");
memset(hstate->num_hints, 0, sizeof(hstate->num_hints));
hstate->scan_hints = NULL;
hstate->init_scan_mask = 0;
+ hstate->current_root = NULL;
hstate->parent_relid = 0;
hstate->parent_hint = NULL;
hstate->parent_index_infos = NIL;
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 */
}
/*
- * 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;
{
/*
* 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(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 *
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;
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;
}
/*
- * Use PG_TRY mechanism to recover GUC parameters and current_hint to the
- * state when this planner started when error occurred in planner.
+ * 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.
*/
PG_TRY();
{
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 (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);
return;
}
- /* Find the parent for this relation */
+ /* Forget about the parent of another subquery */
+ if (root != current_hint->current_root)
+ current_hint->parent_relid = 0;
+
+ /* Find the parent for this relation other than the registered parent */
foreach (l, root->append_rel_list)
{
AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l);
if (appinfo->child_relid == rel->relid)
{
if (current_hint->parent_relid != appinfo->parent_relid)
+ {
new_parent_relid = appinfo->parent_relid;
+ current_hint->current_root = root;
+ }
break;
}
}
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