Add regression tests for processing of concurrent data changes.

Author: Antonin Houska

Makefile

@@ -9,6 +9,7 @@ pg_rewrite--1.2--1.3.sql
 DOCS = pg_rewrite.md
 
 REGRESS = pg_rewrite
+ISOLATION = pg_rewrite_concurrent
 
 PGXS := $(shell $(PG_CONFIG) --pgxs)
 include $(PGXS)

expected/pg_rewrite_concurrent.out

@@ -0,0 +1,95 @@
+Parsed test spec with 2 sessions
+
+starting permutation: wait_before_lock wait_for_s1_sleep do_changes wakeup_before_lock wait_for_backend_exit check
+injection_points_attach
+-----------------------
+                       
+(1 row)
+
+step wait_before_lock: 
+    SELECT rewrite_table_nowait('tbl_src', 'tbl_dst', 'tbl_src_old');
+
+rewrite_table_nowait
+--------------------
+                    
+(1 row)
+
+step wait_for_s1_sleep: 
+DO $$
+BEGIN
+        LOOP
+		PERFORM pg_stat_clear_snapshot();
+
+	        PERFORM
+		FROM pg_stat_activity
+		WHERE (wait_event_type, wait_event)=('InjectionPoint', 'pg_rewrite-before-lock');
+
+		IF FOUND THEN
+			EXIT;
+		END IF;
+
+		PERFORM pg_sleep(.1);
+	END LOOP;
+END;
+$$
+
+step do_changes: 
+	-- Insert one row into each partition.
+	INSERT INTO tbl_src VALUES (2, 2), (3, 3), (5, 5);
+
+	-- Update with no identity change.
+	UPDATE tbl_src SET j=0 WHERE i=1;
+
+	-- Update with identity change but within the same partition.
+	UPDATE tbl_src SET i=6 WHERE i=5;
+
+	-- Cross-partition update.
+	UPDATE tbl_src SET i=7 WHERE i=3;
+
+	-- Update a row we inserted and updated, to check that it's visible.
+	UPDATE tbl_src SET j=4 WHERE i=7;
+
+	-- Delete.
+	DELETE FROM tbl_src WHERE i=4;
+
+step wakeup_before_lock: 
+    SELECT injection_points_wakeup('pg_rewrite-before-lock');
+    SELECT injection_points_detach('pg_rewrite-before-lock');
+
+injection_points_wakeup
+-----------------------
+                       
+(1 row)
+
+injection_points_detach
+-----------------------
+                       
+(1 row)
+
+step wait_for_backend_exit: 
+DO $$
+BEGIN
+        LOOP
+		PERFORM FROM pg_rewrite_progress;
+
+		IF NOT FOUND THEN
+			EXIT;
+		END IF;
+
+		PERFORM pg_sleep(.1);
+	END LOOP;
+END;
+$$;
+
+
+step check: 
+    SELECT i, j FROM tbl_src ORDER BY i, j;
+
+i|j
+-+-
+1|0
+2|2
+6|5
+7|4
+(4 rows)
+

pg_rewrite--1.2--1.3.sql

@@ -4,6 +4,7 @@
 \echo Use "ALTER EXTENSION pg_rewrite UPDATE TO '1.3'" to load this file. \quit
 
 DROP FUNCTION partition_table(text, text, text);
+
 CREATE FUNCTION rewrite_table(
        src_table	text,
        dst_table	text,
@@ -13,3 +14,12 @@ AS 'MODULE_PATHNAME', 'rewrite_table'
 LANGUAGE C
 STRICT;
 
+CREATE FUNCTION rewrite_table_nowait(
+       src_table	text,
+       dst_table	text,
+       src_table_new	text)
+RETURNS void
+AS 'MODULE_PATHNAME', 'rewrite_table_nowait'
+LANGUAGE C
+STRICT;
+