static char qnostr[32];
static const char *current_hint_str = NULL;
+/*
+ * We can utilize in-core generated jumble state in post_parse_analyze_hook.
+ * On the other hand there's a case where we're forced to get hints in
+ * planner_hook, where we don't have a jumble state. If we a query had not a
+ * hint, we need to try to retrieve hints twice or more for one query, which is
+ * the quite common case. To avoid such case, this variables is set true when
+ * we *try* hint retrieval.
+ */
+static bool current_hint_retrieved = false;
+
/* common data for all hints. */
struct Hint
{
HintKeyword hint_keyword;
} HintParser;
+static bool enable_hint_table_check(bool *newval, void **extra, GucSource source);
+static void assign_enable_hint_table(bool newval, void *extra);
+
/* Module callbacks */
void _PG_init(void);
void _PG_fini(void);
static void push_hint(HintState *hstate);
static void pop_hint(void);
+static void pg_hint_plan_post_parse_analyze(ParseState *pstate, Query *query,
+ JumbleState *jstate);
static PlannedStmt *pg_hint_plan_planner(Query *parse, const char *query_string,
int cursorOptions,
ParamListInfo boundParams);
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 bool pg_hint_plan_hints_anywhere = false;
static int plpgsql_recurse_level = 0; /* PLpgSQL recursion level */
static int recurse_level = 0; /* recursion level incl. direct SPI calls */
/* (This could not be above 1) */
static int max_hint_nworkers = -1; /* Maximum nworkers of Workers hints */
+static bool hint_table_deactivated = false;
+
static const struct config_enum_entry parse_messages_level_options[] = {
{"debug", DEBUG2, true},
{"debug5", DEBUG5, false},
};
/* Saved hook values in case of unload */
+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;
false,
PGC_USERSET,
0,
+ enable_hint_table_check,
+ assign_enable_hint_table,
+ NULL);
+
+ DefineCustomBoolVariable("pg_hint_plan.hints_anywhere",
+ "Read hints from anywhere in a query.",
+ "This option lets pg_hint_plan ignore syntax so be cautious for false reads.",
+ &pg_hint_plan_hints_anywhere,
+ false,
+ PGC_USERSET,
+ 0,
NULL,
NULL,
NULL);
+ EmitWarningsOnPlaceholders("pg_hint_plan");
+
/* Install hooks. */
+ 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;
*var_ptr = NULL;
}
+static bool
+enable_hint_table_check(bool *newval, void **extra, GucSource source)
+{
+ if (*newval)
+ {
+ EnableQueryId();
+
+ if (!IsQueryIdEnabled())
+ {
+ GUC_check_errmsg("table hint is not activated because queryid is not available");
+ GUC_check_errhint("Set compute_query_id to on or auto to use hint table.");
+ return false;
+ }
+ }
+
+ return true;
+}
+
+static void
+assign_enable_hint_table(bool newval, void *extra)
+{
+ if (!newval)
+ hint_table_deactivated = false;
+}
+
/*
* create and delete functions the hint object
*/
hint_head = strstr(p, HINT_START);
if (hint_head == NULL)
return NULL;
- for (;p < hint_head; p++)
+ if (!pg_hint_plan_hints_anywhere)
{
- /*
- * Allow these characters precedes hint comment:
- * - digits
- * - alphabets which are in ASCII range
- * - space, tabs and new-lines
- * - underscores, for identifier
- * - commas, for SELECT clause, EXPLAIN and PREPARE
- * - parentheses, for EXPLAIN and PREPARE
- *
- * Note that we don't use isalpha() nor isalnum() in ctype.h here to
- * avoid behavior which depends on locale setting.
- */
- if (!(*p >= '0' && *p <= '9') &&
- !(*p >= 'A' && *p <= 'Z') &&
- !(*p >= 'a' && *p <= 'z') &&
- !isspace(*p) &&
- *p != '_' &&
- *p != ',' &&
- *p != '(' && *p != ')')
- return NULL;
+ for (;p < hint_head; p++)
+ {
+ /*
+ * Allow these characters precedes hint comment:
+ * - digits
+ * - alphabets which are in ASCII range
+ * - space, tabs and new-lines
+ * - underscores, for identifier
+ * - commas, for SELECT clause, EXPLAIN and PREPARE
+ * - parentheses, for EXPLAIN and PREPARE
+ *
+ * Note that we don't use isalpha() nor isalnum() in ctype.h here to
+ * avoid behavior which depends on locale setting.
+ */
+ if (!(*p >= '0' && *p <= '9') &&
+ !(*p >= 'A' && *p <= 'Z') &&
+ !(*p >= 'a' && *p <= 'z') &&
+ !isspace(*p) &&
+ *p != '_' &&
+ *p != ',' &&
+ *p != '(' && *p != ')')
+ return NULL;
+ }
}
- len = strlen(HINT_START);
- head = (char *) p;
- p += len;
+ head = (char *)hint_head;
+ p = head + strlen(HINT_START);
skip_space(p);
/* find hint end keyword. */
hint->base.keyword));
else if (nworkers < 0)
hint_ereport(hint->nworkers_str,
- ("number of workers must be positive: %s",
+ ("number of workers must be greater than zero: %s",
hint->base.keyword));
else if (nworkers > max_worker_processes)
hint_ereport(hint->nworkers_str,
* Retrieve and store hint string from given query or from the hint table.
*/
static void
-get_current_hint_string(Query *query, const char *query_str)
+get_current_hint_string(Query *query, const char *query_str,
+ JumbleState *jstate)
{
MemoryContext oldcontext;
- /* do nothing while scanning hint table */
- if (hint_inhibit_level > 0)
+ /* We shouldn't get here for internal queries. */
+ Assert (hint_inhibit_level == 0);
+
+ /* We shouldn't get here if hint is disabled. */
+ Assert (pg_hint_plan_enable_hint);
+
+ /* Do not anything if we have already tried to get hints for this query. */
+ if (current_hint_retrieved)
+ return;
+
+ /* No way to retrieve hints from empty string. */
+ if (!query_str)
return;
+ /* Don't parse the current query hereafter */
+ current_hint_retrieved = true;
+
/* Make sure trashing old hint string */
if (current_hint_str)
{
current_hint_str = NULL;
}
- /* Return if nothing to do. */
- if (!pg_hint_plan_enable_hint || !query_str)
- return;
-
/* increment the query number */
qnostr[0] = 0;
if (debug_level > 1)
/* search the hint table for a hint if requested */
if (pg_hint_plan_enable_hint_table)
{
- JumbleState *jstate;
- int query_len;
- char *normalized_query;
+ int query_len;
+ char *normalized_query;
+
+ if (!IsQueryIdEnabled())
+ {
+ /*
+ * compute_query_id was turned off while enable_hint_table is
+ * on. Do not go ahead and complain once until it is turned on
+ * again.
+ */
+ if (!hint_table_deactivated)
+ ereport(WARNING,
+ (errmsg ("hint table feature is deactivated because queryid is not available"),
+ errhint("Set compute_query_id to \"auto\" or \"on\" to use hint table.")));
+
+ hint_table_deactivated = true;
+ return;
+ }
+
+ if (hint_table_deactivated)
+ {
+ ereport(LOG, (errmsg ("hint table feature is reactivated")));
+ hint_table_deactivated = false;
+ }
- jstate = JumbleQuery(query, query_str);
+ if (!jstate)
+ jstate = JumbleQuery(query, query_str);
+
+ if (!jstate)
+ return;
/*
* Normalize the query string by replacing constants with '?'
if (debug_level > 1)
{
- if (debug_level == 1 && query_str && debug_query_string &&
+ if (debug_level == 2 && query_str && debug_query_string &&
strcmp(query_str, debug_query_string))
ereport(pg_hint_plan_debug_message_level,
(errmsg("hints in comment=\"%s\"",
}
/*
+ * Retrieve hint string from the current query.
+ */
+static void
+pg_hint_plan_post_parse_analyze(ParseState *pstate, Query *query,
+ JumbleState *jstate)
+{
+ if (prev_post_parse_analyze_hook)
+ prev_post_parse_analyze_hook(pstate, query, jstate);
+
+ if (!pg_hint_plan_enable_hint || hint_inhibit_level > 0)
+ return;
+
+ /* always retrieve hint from the top-level query string */
+ if (plpgsql_recurse_level == 0)
+ current_hint_retrieved = false;
+
+ /*
+ * Jumble state is required when hint table is used. This is the only
+ * chance to have one already generated in-core. If it's not the case, no
+ * use to do the work now and pg_hint_plan_planner() will do the all work.
+ */
+ if (jstate)
+ get_current_hint_string(query, pstate->p_sourcetext, jstate);
+}
+
+/*
* Read and set up hint information
*/
static PlannedStmt *
goto standard_planner_proc;
}
- /* always retrieve hint from the top-level query string */
- if (plpgsql_recurse_level == 0 && current_hint_str)
+ /*
+ * SQL commands invoked in plpgsql functions may also have hints. In that
+ * case override the upper level hint by the new hint.
+ */
+ if (plpgsql_recurse_level > 0)
{
- pfree((void *)current_hint_str);
+ const char *tmp_hint_str = current_hint_str;
+
+ /* don't let get_current_hint_string free this string */
current_hint_str = NULL;
- }
- get_current_hint_string(parse, query_string);
+ current_hint_retrieved = false;
- /* No hint, go the normal way */
+ get_current_hint_string(parse, query_string, NULL);
+
+ if (current_hint_str == NULL)
+ current_hint_str = tmp_hint_str;
+ else if (tmp_hint_str != NULL)
+ pfree((void *)tmp_hint_str);
+ }
+ else
+ get_current_hint_string(parse, query_string, NULL);
+
+ /* No hints, go the normal way */
if (!current_hint_str)
goto standard_planner_proc;
{
/*
* Rollback changes of GUC parameters, and pop current hint context
- * from hint stack to rewind the state.
+ * from hint stack to rewind the state. current_hint_str will be freed
+ * by context deletion.
*/
current_hint_str = prev_hint_str;
recurse_level--;
/*
* current_hint_str is useless after planning of the top-level query.
+ * There's a case where the caller has multiple queries. This causes hint
+ * parsing multiple times for the same string but we don't have a simple
+ * and reliable way to distinguish that case from the case where of
+ * separate queries.
*/
- if (recurse_level < 1 && current_hint_str)
- {
- pfree((void *)current_hint_str);
- current_hint_str = NULL;
- }
+ if (recurse_level < 1)
+ current_hint_retrieved = false;
/* Print hint in debug mode. */
if (debug_level == 1)
pfree(indexname);
}
- if (debug_level == 1)
+ if (debug_level > 0)
{
StringInfoData rel_buf;
char *disprelname = "";
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