Add partial support (creation) of expression based partitions

Author: ildus

.gitignore

@@ -10,3 +10,5 @@ regression.out
 *.gcno
 *.gcov
 pg_pathman--*.sql
+tags
+cscope*

hash.sql

@@ -35,8 +35,7 @@ BEGIN
 	PERFORM @extschema@.common_relation_checks(parent_relid, attribute);
 
 	/* Insert new entry to pathman config */
-	INSERT INTO @extschema@.pathman_config (partrel, attname, parttype)
-	VALUES (parent_relid, attribute, 1);
+	PERFORM @extschema@.add_to_pathman_config(parent_relid, attribute);
 
 	/* Create partitions */
 	PERFORM @extschema@.create_hash_partitions_internal(parent_relid,
@@ -48,13 +47,13 @@ BEGIN
 	/* Notify backend about changes */
 	PERFORM @extschema@.on_create_partitions(parent_relid);
 
-	/* Copy data */
+	/* Copy data
 	IF partition_data = true THEN
 		PERFORM @extschema@.set_enable_parent(parent_relid, false);
 		PERFORM @extschema@.partition_data(parent_relid);
 	ELSE
 		PERFORM @extschema@.set_enable_parent(parent_relid, true);
-	END IF;
+	END IF; */
 
 	RETURN partitions_count;
 END
@@ -299,14 +298,3 @@ LANGUAGE C STRICT;
 CREATE OR REPLACE FUNCTION @extschema@.get_hash_part_idx(INTEGER, INTEGER)
 RETURNS INTEGER AS 'pg_pathman', 'get_hash_part_idx'
 LANGUAGE C STRICT;
-
-/*
- * Build hash condition for a CHECK CONSTRAINT
- */
-CREATE OR REPLACE FUNCTION @extschema@.build_hash_condition(
-	attribute_type		REGTYPE,
-	attribute			TEXT,
-	partitions_count	INT4,
-	partitions_index	INT4)
-RETURNS TEXT AS 'pg_pathman', 'build_hash_condition'
-LANGUAGE C STRICT;

init.sql

@@ -35,6 +35,7 @@ LANGUAGE C;
 CREATE TABLE IF NOT EXISTS @extschema@.pathman_config (
 	partrel			REGCLASS NOT NULL PRIMARY KEY,
 	attname			TEXT NOT NULL,
+	atttype			OID NOT NULL,
 	parttype		INTEGER NOT NULL,
 	range_interval	TEXT,
 
@@ -427,7 +428,7 @@ LANGUAGE plpgsql STRICT;
  */
 CREATE OR REPLACE FUNCTION @extschema@.common_relation_checks(
 	relation		REGCLASS,
-	p_attribute		TEXT)
+	expression		TEXT)
 RETURNS BOOLEAN AS
 $$
 DECLARE
@@ -450,8 +451,8 @@ BEGIN
 		RAISE EXCEPTION 'relation "%" has already been partitioned', relation;
 	END IF;
 
-	IF @extschema@.is_attribute_nullable(relation, p_attribute) THEN
-		RAISE EXCEPTION 'partitioning key "%" must be NOT NULL', p_attribute;
+	IF NOT @extschema@.is_expression_suitable(relation, expression) THEN
+		RAISE EXCEPTION 'partitioning expression "%" is not suitable', expression;
 	END IF;
 
 	/* Check if there are foreign keys that reference the relation */
@@ -467,7 +468,7 @@ BEGIN
 		RAISE EXCEPTION 'relation "%" is referenced from other relations', relation;
 	END IF;
 
-	RETURN TRUE;
+	RETURN FALSE;
 END
 $$
 LANGUAGE plpgsql;
@@ -796,6 +797,15 @@ CREATE OR REPLACE FUNCTION @extschema@.is_attribute_nullable(
 RETURNS BOOLEAN AS 'pg_pathman', 'is_attribute_nullable'
 LANGUAGE C STRICT;
 
+/*
+ * Checks if expression is suitable
+ */
+CREATE OR REPLACE FUNCTION @extschema@.is_expression_suitable(
+	relid	REGCLASS,
+	expr	TEXT)
+RETURNS BOOLEAN AS 'pg_pathman', 'is_expression_suitable'
+LANGUAGE C STRICT;
+
 /*
  * Check if regclass is date or timestamp.
  */

sql/pathman_basic.sql

@@ -11,7 +11,9 @@ CREATE TABLE test.hash_rel (
 INSERT INTO test.hash_rel VALUES (1, 1);
 INSERT INTO test.hash_rel VALUES (2, 2);
 INSERT INTO test.hash_rel VALUES (3, 3);
-SELECT pathman.create_hash_partitions('test.hash_rel', 'value', 3);
+:gdb
+SELECT pg_sleep(10);
+SELECT pathman.create_hash_partitions('test.hash_rel', 'value + 1', 3);
 ALTER TABLE test.hash_rel ALTER COLUMN value SET NOT NULL;
 SELECT pathman.create_hash_partitions('test.hash_rel', 'value', 3, partition_data:=false);
 EXPLAIN (COSTS OFF) SELECT * FROM test.hash_rel;

src/hooks.c

@@ -255,10 +255,11 @@ pathman_rel_pathlist_hook(PlannerInfo *root,
 			int32			type_mod;
 			TypeCacheEntry *tce;
 
-			/* Make Var from partition column */
-			get_rte_attribute_type(rte, prel->attnum,
+			/* Make Var from patition column */
+			/* FIX: this */
+			get_rte_attribute_type(rte, 0,
 								   &vartypeid, &type_mod, &varcollid);
-			var = makeVar(rti, prel->attnum, vartypeid, type_mod, varcollid, 0);
+			var = makeVar(rti, 0, vartypeid, type_mod, varcollid, 0);
 			var->location = -1;
 
 			/* Determine operator type */

src/include/init.h

@@ -132,7 +132,6 @@ void unload_config(void);
 
 void fill_prel_with_partitions(const Oid *partitions,
 							   const uint32 parts_count,
-							   const char *part_column_name,
 							   PartRelationInfo *prel);
 
 /* Result of find_inheritance_children_array() */
@@ -149,11 +148,9 @@ find_children_status find_inheritance_children_array(Oid parentrelId,
 													 uint32 *children_size,
 													 Oid **children);
 
-char *build_check_constraint_name_relid_internal(Oid relid,
-												 AttrNumber attno);
+char *build_check_constraint_name_relid_internal(Oid relid);
 
-char *build_check_constraint_name_relname_internal(const char *relname,
-												   AttrNumber attno);
+char *build_check_constraint_name_relname_internal(const char *relname);
 
 char *build_sequence_name_internal(Oid relid);
 

src/include/partition_creation.h

@@ -66,17 +66,24 @@ bool check_range_available(Oid parent_relid,
 
 /* HASH constraints */
 Constraint * build_hash_check_constraint(Oid child_relid,
-										 char *attname,
+										 const char *expr,
 										 uint32 part_idx,
 										 uint32 part_count,
 										 Oid value_type);
 
-Node * build_raw_hash_check_tree(char *attname,
+Node * build_raw_hash_check_tree(const char *base_expr,
 								 uint32 part_idx,
-								 uint32 part_count, Oid value_type);
+								 uint32 part_count,
+								 Oid relid,
+								 Oid value_type);
 
 void drop_check_constraint(Oid relid, AttrNumber attnum);
 
+/* expression parsing functions */
+Node *get_expression_node(Oid relid, const char *expr, bool analyze);
+Oid get_partition_expr_type(Oid relid, const char *expr);
+
+
 
 /* Partitioning callback type */
 typedef enum

src/include/partition_filter.h

@@ -25,7 +25,9 @@
 #endif
 
 
-#define ERR_PART_ATTR_NULL		"partitioned column's value should not be NULL"
+#define ERR_PART_ATTR_NULL		"partition expression's value should not be NULL"
+#define ERR_PART_ATTR_MULTIPLE_RESULTS \
+		"partition expression's value should be single, not set"
 #define ERR_PART_ATTR_NO_PART	"no suitable partition for key '%s'"
 #define ERR_PART_ATTR_MULTIPLE	"PartitionFilter selected more than one partition"
 

src/include/pathman.h

@@ -16,6 +16,7 @@
 #include "rangeset.h"
 
 #include "postgres.h"
+#include "fmgr.h"
 #include "nodes/makefuncs.h"
 #include "nodes/primnodes.h"
 #include "nodes/execnodes.h"
@@ -43,11 +44,12 @@
  * Definitions for the "pathman_config" table.
  */
 #define PATHMAN_CONFIG						"pathman_config"
-#define Natts_pathman_config				4
+#define Natts_pathman_config				5
 #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) */
+#define Anum_pathman_config_atttype			3	/* partitioned atttype */
+#define Anum_pathman_config_parttype		4	/* partitioning type (1|2) */
+#define Anum_pathman_config_range_interval	5	/* interval for RANGE pt. (text) */
 
 /* type modifier (typmod) for 'range_interval' */
 #define PATHMAN_CONFIG_interval_typmod		-1

src/include/relation_info.h

@@ -15,6 +15,8 @@
 #include "postgres.h"
 #include "access/attnum.h"
 #include "fmgr.h"
+#include "nodes/nodes.h"
+#include "nodes/primnodes.h"
 #include "port/atomics.h"
 #include "storage/lock.h"
 #include "utils/datum.h"
@@ -126,9 +128,9 @@ typedef struct
 	RangeEntry	   *ranges;			/* per-partition range entry or NULL */
 
 	PartType		parttype;		/* partitioning type (HASH | RANGE) */
-	AttrNumber		attnum;			/* partitioned column's index */
-	Oid				atttype;		/* partitioned column's type */
-	int32			atttypmod;		/* partitioned column type modifier */
+	Expr		   *expr;
+	Oid				atttype;		/* expression type */
+	int32			atttypmod;		/* expression type modifier */
 	bool			attbyval;		/* is partitioned column stored by value? */
 	int16			attlen;			/* length of the partitioned column's type */
 	int				attalign;		/* alignment of the part column's type */
@@ -191,8 +193,8 @@ PrelLastChild(const PartRelationInfo *prel)
 
 
 const PartRelationInfo *refresh_pathman_relation_info(Oid relid,
-													  PartType partitioning_type,
-													  const char *part_column_name,
+													  Datum *values,
+													  bool *isnull,
 													  bool allow_incomplete);
 void invalidate_pathman_relation_info(Oid relid, bool *found);
 void remove_pathman_relation_info(Oid relid);