introduce function add_to_pathman_config(), remove useless column 'id' from pathman_config, replace pg_pathman_enable & initialization_needed with struct PathmanInitState, small fixes & refactoring

Author: funbringer

expected/pg_pathman.out

@@ -1141,8 +1141,8 @@ SELECT * FROM test.range_rel WHERE dt = '2015-03-15';
 DROP TABLE test.range_rel CASCADE;
 NOTICE:  drop cascades to 16 other objects
 SELECT * FROM pathman.pathman_config;
- id | partrel | attname | parttype | range_interval 
-----+---------+---------+----------+----------------
+ partrel | attname | parttype | range_interval 
+---------+---------+----------+----------------
 (0 rows)
 
 /* Check overlaps */
@@ -1325,9 +1325,9 @@ SELECT pathman.create_partitions_from_range('test."RangeRel"', 'dt', '2015-01-01
 DROP TABLE test."RangeRel" CASCADE;
 NOTICE:  drop cascades to 5 other objects
 SELECT * FROM pathman.pathman_config;
- id |      partrel       | attname | parttype | range_interval 
-----+--------------------+---------+----------+----------------
-  9 | test.num_range_rel | id      |        2 | 1000
+      partrel       | attname | parttype | range_interval 
+--------------------+---------+----------+----------------
+ test.num_range_rel | id      |        2 | 1000
 (1 row)
 
 CREATE TABLE test."RangeRel" (

init.sql

@@ -18,8 +18,7 @@
  *		range_interval - base interval for RANGE partitioning as string
  */
 CREATE TABLE IF NOT EXISTS @extschema@.pathman_config (
-	id				SERIAL PRIMARY KEY,
-	partrel			REGCLASS NOT NULL,
+	partrel			REGCLASS NOT NULL PRIMARY KEY,
 	attname			TEXT NOT NULL,
 	parttype		INTEGER NOT NULL,
 	range_interval	TEXT,
@@ -100,7 +99,7 @@ BEGIN
 		RAISE EXCEPTION 'Partitioning key ''%'' must be NOT NULL', p_attribute;
 	END IF;
 
-	/* Check if there are foreign keys reference to the relation */
+	/* Check if there are foreign keys that reference the relation */
 	FOR v_rec IN (SELECT *
 				  FROM pg_constraint WHERE confrelid = p_relation::regclass::oid)
 	LOOP
@@ -243,12 +242,9 @@ CREATE OR REPLACE FUNCTION @extschema@.drop_triggers(
 	parent_relid	REGCLASS)
 RETURNS VOID AS
 $$
-DECLARE
-	funcname	TEXT;
-
 BEGIN
-	funcname := @extschema@.build_update_trigger_func_name(parent_relid);
-	EXECUTE format('DROP FUNCTION IF EXISTS %s() CASCADE', funcname);
+	EXECUTE format('DROP FUNCTION IF EXISTS %s() CASCADE',
+				   @extschema@.build_update_trigger_func_name(parent_relid));
 END
 $$ LANGUAGE plpgsql;
 
@@ -317,12 +313,14 @@ EXECUTE PROCEDURE @extschema@.pathman_ddl_trigger_func();
 
 
 /*
- * Check if regclass is date or timestamp
+ * Attach partitioned table
  */
-CREATE OR REPLACE FUNCTION @extschema@.is_date_type(
-	typid	REGTYPE)
-RETURNS BOOLEAN AS 'pg_pathman', 'is_date_type'
-LANGUAGE C STRICT;
+CREATE OR REPLACE FUNCTION @extschema@.add_to_pathman_config(
+	parent_relid	REGCLASS,
+	attname			TEXT,
+	range_interval	TEXT DEFAULT NULL)
+RETURNS BOOLEAN AS 'pg_pathman', 'add_to_pathman_config'
+LANGUAGE C;
 
 
 CREATE OR REPLACE FUNCTION @extschema@.on_create_partitions(
@@ -341,6 +339,21 @@ RETURNS VOID AS 'pg_pathman', 'on_partitions_removed'
 LANGUAGE C STRICT;
 
 
+/*
+ * Get parent of pg_pathman's partition.
+ */
+CREATE OR REPLACE FUNCTION @extschema@.get_parent_of_partition(REGCLASS)
+RETURNS REGCLASS AS 'pg_pathman', 'get_parent_of_partition_pl'
+LANGUAGE C STRICT;
+
+/*
+ * Check if regclass is date or timestamp
+ */
+CREATE OR REPLACE FUNCTION @extschema@.is_date_type(
+	typid	REGTYPE)
+RETURNS BOOLEAN AS 'pg_pathman', 'is_date_type'
+LANGUAGE C STRICT;
+
 /*
  * Checks if attribute is nullable
  */
@@ -389,10 +402,3 @@ LANGUAGE C STRICT;
 CREATE OR REPLACE FUNCTION @extschema@.debug_capture()
 RETURNS VOID AS 'pg_pathman', 'debug_capture'
 LANGUAGE C STRICT;
-
-/*
- * Get parent of pg_pathman's partition.
- */
-CREATE OR REPLACE FUNCTION @extschema@.get_parent_of_partition(REGCLASS)
-RETURNS REGCLASS AS 'pg_pathman', 'get_parent_of_partition_pl'
-LANGUAGE C STRICT;

src/hooks.c

@@ -356,15 +356,8 @@ pg_pathman_enable_assign_hook(bool newval, void *extra)
 	elog(DEBUG2, "pg_pathman_enable_assign_hook() [newval = %s] triggered",
 		  newval ? "true" : "false");
 
-	if (initialization_needed)
-	{
-		elog(DEBUG2, "pg_pathman is not yet initialized, "
-					 "pg_pathman.enable is set to false");
-		return;
-	}
-
 	/* Return quickly if nothing has changed */
-	if (newval == (pg_pathman_enable &&
+	if (newval == (pg_pathman_init_state.pg_pathman_enable &&
 				   pg_pathman_enable_runtimeappend &&
 				   pg_pathman_enable_runtime_merge_append &&
 				   pg_pathman_enable_partition_filter))
@@ -459,7 +452,7 @@ pathman_post_parse_analysis_hook(ParseState *pstate, Query *query)
 
 	/* Load config if pg_pathman exists & it's still necessary */
 	if (IsPathmanEnabled() &&
-		initialization_needed &&
+		!IsPathmanInitialized() &&
 		/* Now evaluate the most expensive clause */
 		get_pathman_schema() != InvalidOid)
 	{

src/init.c

@@ -38,23 +38,27 @@
 #include "utils/snapmgr.h"
 
 
+/* Help user in case of emergency */
+#define INIT_ERROR_HINT "pg_pathman will be disabled to allow you to resolve this issue"
+
 /* Initial size of 'partitioned_rels' table */
 #define PART_RELS_SIZE	10
 #define CHILD_FACTOR	500
 
+
 /* Storage for PartRelationInfos */
-HTAB		   *partitioned_rels = NULL;
+HTAB			   *partitioned_rels = NULL;
 
 /* Storage for PartParentInfos */
-HTAB		   *parent_cache = NULL;
+HTAB			   *parent_cache = NULL;
 
-bool			initialization_needed = true;
-static bool		relcache_callback_needed = true;
-
-/* Help user in case of emergency */
-#define INIT_ERROR_HINT "pg_pathman will be disabled to allow you fix this"
+/* pg_pathman's init status */
+PathmanInitState 	pg_pathman_init_state;
 
+/* Shall we install new relcache callback? */
+static bool			relcache_callback_needed = true;
 
+/* Functions for various local caches */
 static bool init_pathman_relation_oids(void);
 static void fini_pathman_relation_oids(void);
 static void init_local_cache(void);
@@ -81,6 +85,41 @@ static bool read_opexpr_const(const OpExpr *opexpr,
 static int oid_cmp(const void *p1, const void *p2);
 
 
+/*
+ * Save and restore main init state.
+ */
+
+void
+save_pathman_init_state(PathmanInitState *temp_init_state)
+{
+	*temp_init_state = pg_pathman_init_state;
+}
+
+void
+restore_pathman_init_state(const PathmanInitState *temp_init_state)
+{
+	pg_pathman_init_state = *temp_init_state;
+}
+
+/*
+ * Create main GUC.
+ */
+void
+init_main_pathman_toggle(void)
+{
+	/* Main toggle, load_config() will enable it */
+	DefineCustomBoolVariable("pg_pathman.enable",
+							 "Enables pg_pathman's optimizations during the planner stage",
+							 NULL,
+							 &pg_pathman_init_state.pg_pathman_enable,
+							 true,
+							 PGC_USERSET,
+							 0,
+							 NULL,
+							 pg_pathman_enable_assign_hook,
+							 NULL);
+}
+
 /*
  * Create local PartRelationInfo cache & load pg_pathman's config.
  * Return true on success. May occasionally emit ERROR.
@@ -111,7 +150,7 @@ load_config(void)
 	}
 
 	/* Mark pg_pathman as initialized */
-	initialization_needed = false;
+	pg_pathman_init_state.initialization_needed = false;
 
 	elog(DEBUG2, "pg_pathman's config has been loaded successfully [%u]", MyProcPid);
 
@@ -131,7 +170,7 @@ unload_config(void)
 	fini_local_cache();
 
 	/* Mark pg_pathman as uninitialized */
-	initialization_needed = true;
+	pg_pathman_init_state.initialization_needed = true;
 
 	elog(DEBUG2, "pg_pathman's config has been unloaded successfully [%u]", MyProcPid);
 }
@@ -539,7 +578,6 @@ pathman_config_contains_relation(Oid relid, Datum *values, bool *isnull,
 			heap_deform_tuple(htup, RelationGetDescr(rel), values, isnull);
 
 			/* Perform checks for non-NULL columns */
-			Assert(!isnull[Anum_pathman_config_id - 1]);
 			Assert(!isnull[Anum_pathman_config_partrel - 1]);
 			Assert(!isnull[Anum_pathman_config_attname - 1]);
 			Assert(!isnull[Anum_pathman_config_parttype - 1]);

src/init.h

@@ -15,14 +15,63 @@
 
 #include "postgres.h"
 #include "storage/lmgr.h"
-#include "utils/snapshot.h"
+#include "utils/guc.h"
 #include "utils/hsearch.h"
+#include "utils/snapshot.h"
+
+
+/*
+ * pg_pathman's initialization state structure.
+ */
+typedef struct
+{
+	bool 	pg_pathman_enable;		/* GUC variable implementation */
+	bool	initialization_needed;	/* do we need to perform init? */
+} PathmanInitState;
 
 
-extern HTAB	   *partitioned_rels;
-extern HTAB	   *parent_cache;
-extern bool		initialization_needed;
+extern HTAB				   *partitioned_rels;
+extern HTAB				   *parent_cache;
 
+/* pg_pathman's initialization state */
+extern PathmanInitState 	pg_pathman_init_state;
+
+
+/*
+ * Check if pg_pathman is initialized.
+ */
+#define IsPathmanInitialized()	( !pg_pathman_init_state.initialization_needed )
+
+/*
+ * Check if pg_pathman is enabled.
+ */
+#define IsPathmanEnabled()		( pg_pathman_init_state.pg_pathman_enable )
+
+/*
+ * Check if pg_pathman is initialized & enabled.
+ */
+#define IsPathmanReady()		( IsPathmanInitialized() && IsPathmanEnabled() )
+
+/*
+ * Emergency disable mechanism.
+ */
+#define DisablePathman() \
+	do { \
+		pg_pathman_init_state.pg_pathman_enable = false; \
+		pg_pathman_init_state.initialization_needed = true; \
+	} while (0)
+
+
+/*
+ * Save and restore PathmanInitState.
+ */
+void save_pathman_init_state(PathmanInitState *temp_init_state);
+void restore_pathman_init_state(const PathmanInitState *temp_init_state);
+
+/*
+ * Create main GUC variable.
+ */
+void init_main_pathman_toggle(void);
 
 Size estimate_pathman_shmem_size(void);
 void init_shmem_config(void);

src/pathman.h

@@ -11,7 +11,6 @@
 #ifndef PATHMAN_H
 #define PATHMAN_H
 
-#include "init.h"
 #include "relation_info.h"
 #include "rangeset.h"
 
@@ -43,16 +42,17 @@
  * Definitions for the "pathman_config" table.
  */
 #define PATHMAN_CONFIG						"pathman_config"
-#define Natts_pathman_config				5
-#define Anum_pathman_config_id				1	/* primary key */
-#define Anum_pathman_config_partrel			2	/* partitioned relation (regclass) */
-#define Anum_pathman_config_attname			3	/* partitioned column (text) */
-#define Anum_pathman_config_parttype		4	/* partitioning type (1|2) */
-#define Anum_pathman_config_range_interval	5	/* interval for RANGE pt. (text) */
+#define Natts_pathman_config				4
+#define Anum_pathman_config_partrel			1	/* partitioned relation (regclass) */
+#define Anum_pathman_config_attname			2	/* partitioned column (text) */
+#define Anum_pathman_config_parttype		3	/* partitioning type (1|2) */
+#define Anum_pathman_config_range_interval	4	/* interval for RANGE pt. (text) */
 
 /* type modifier (typmod) for 'range_interval' */
 #define PATHMAN_CONFIG_interval_typmod		-1
 
+#define PATHMAN_CONFIG_ID_SEQ				"pathman_config_id_seq"
+
 /*
  * Cache current PATHMAN_CONFIG relid (set during load_config()).
  */
@@ -96,27 +96,9 @@ extern List			   *inheritance_enabled_relids;
  */
 extern List			   *inheritance_disabled_relids;
 
-extern bool 			pg_pathman_enable;
 extern PathmanState    *pmstate;
 
 
-#define PATHMAN_GET_DATUM(value, by_val) \
-	( (by_val) ? (Datum) (value) : PointerGetDatum(&value) )
-
-/*
- * Check if pg_pathman is initialized & enabled.
- */
-#define IsPathmanReady() ( !initialization_needed && pg_pathman_enable )
-
-#define IsPathmanEnabled() ( pg_pathman_enable )
-
-#define DisablePathman() \
-	do { \
-		pg_pathman_enable = false; \
-		initialization_needed = true; \
-	} while (0)
-
-
 int append_child_relation(PlannerInfo *root, RelOptInfo *rel, Index rti,
 						  RangeTblEntry *rte, int index, Oid childOID, List *wrappers);