Add more tests for FSM.

In commit b0eaa4c51b, we left out a test that used a vacuum to remove dead
rows as the behavior of test was not predictable.  This test has been
rewritten to use fillfactor instead to control free space.  Since we no
longer need to remove dead rows as part of the test, put the fsm regression
test in a parallel group.

Author: John Naylor
Reviewed-by: Amit Kapila
Discussion: https://postgr.es/m/CAA4eK1L=qWp_bJ5aTc9+fy4Ewx2LPaLWY-RbR4a60g_rupCKnQ@mail.gmail.com

src/test/regress/expected/fsm.out

@@ -1,15 +1,40 @@
 --
 -- Free Space Map test
 --
+SELECT current_setting('block_size')::integer AS blocksize,
+current_setting('block_size')::integer / 8 AS strsize
+\gset
 CREATE TABLE fsm_check_size (num int, str text);
--- With one block, there should be no FSM
-INSERT INTO fsm_check_size VALUES(1, 'a');
+-- Fill 3 blocks with one record each
+ALTER TABLE fsm_check_size SET (fillfactor=15);
+INSERT INTO fsm_check_size SELECT i, rpad('', :strsize, 'a')
+FROM generate_series(1,3) i;
+-- There should be no FSM
 VACUUM fsm_check_size;
-SELECT pg_relation_size('fsm_check_size', 'main') AS heap_size,
-pg_relation_size('fsm_check_size', 'fsm') AS fsm_size;
- heap_size | fsm_size 
------------+----------
-      8192 |        0
+SELECT pg_relation_size('fsm_check_size', 'main') / :blocksize AS heap_nblocks,
+pg_relation_size('fsm_check_size', 'fsm') / :blocksize AS fsm_nblocks;
+ heap_nblocks | fsm_nblocks 
+--------------+-------------
+            3 |           0
+(1 row)
+
+-- The following operations are for testing the functionality of the local
+-- in-memory map. In particular, we want to be able to insert into some
+-- other block than the one at the end of the heap, without using a FSM.
+-- Fill most of the last block
+ALTER TABLE fsm_check_size SET (fillfactor=100);
+INSERT INTO fsm_check_size SELECT i, rpad('', :strsize, 'a')
+FROM generate_series(101,105) i;
+-- Make sure records can go into any block but the last one
+ALTER TABLE fsm_check_size SET (fillfactor=30);
+-- Insert large record and make sure it does not cause the relation to extend
+INSERT INTO fsm_check_size VALUES (111, rpad('', :strsize, 'a'));
+VACUUM fsm_check_size;
+SELECT pg_relation_size('fsm_check_size', 'main') / :blocksize AS heap_nblocks,
+pg_relation_size('fsm_check_size', 'fsm') / :blocksize AS fsm_nblocks;
+ heap_nblocks | fsm_nblocks 
+--------------+-------------
+            3 |           0
 (1 row)
 
 -- Extend table with enough blocks to exceed the FSM threshold
@@ -26,23 +51,23 @@ num = 11;
 END;
 $$;
 VACUUM fsm_check_size;
-SELECT pg_relation_size('fsm_check_size', 'fsm') AS fsm_size;
- fsm_size 
-----------
-    24576
+SELECT pg_relation_size('fsm_check_size', 'fsm') / :blocksize AS fsm_nblocks;
+ fsm_nblocks 
+-------------
+           3
 (1 row)
 
 -- Add long random string to extend TOAST table to 1 block
 INSERT INTO fsm_check_size
 VALUES(0, (SELECT string_agg(md5(chr(i)), '')
-		   FROM generate_series(1,100) i));
+		   FROM generate_series(1, :blocksize / 100) i));
 VACUUM fsm_check_size;
-SELECT pg_relation_size(reltoastrelid, 'main') AS toast_size,
-pg_relation_size(reltoastrelid, 'fsm') AS toast_fsm_size
+SELECT pg_relation_size(reltoastrelid, 'main') / :blocksize AS toast_nblocks,
+pg_relation_size(reltoastrelid, 'fsm') / :blocksize AS toast_fsm_nblocks
 FROM pg_class WHERE relname = 'fsm_check_size';
- toast_size | toast_fsm_size 
-------------+----------------
-       8192 |              0
+ toast_nblocks | toast_fsm_nblocks 
+---------------+-------------------
+             1 |                 0
 (1 row)
 
 DROP TABLE fsm_check_size;

src/test/regress/parallel_schedule

@@ -23,7 +23,7 @@ test: numerology
 # ----------
 # The second group of parallel tests
 # ----------
-test: point lseg line box path polygon circle date time timetz timestamp timestamptz interval inet macaddr macaddr8 tstypes
+test: point lseg line box path polygon circle date time timetz timestamp timestamptz interval inet macaddr macaddr8 tstypes fsm
 
 # ----------
 # Another group of parallel tests
@@ -68,12 +68,6 @@ test: create_aggregate create_function_3 create_cast constraints triggers inheri
 # ----------
 test: sanity_check
 
-# ----------
-# fsm does a delete followed by vacuum, and running it in parallel can prevent
-# removal of rows.
-# ----------
-test: fsm
-
 # ----------
 # Believe it or not, select creates a table, subsequent
 # tests need.

src/test/regress/serial_schedule

@@ -40,6 +40,7 @@ test: inet
 test: macaddr
 test: macaddr8
 test: tstypes
+test: fsm
 test: geometry
 test: horology
 test: regex
@@ -81,7 +82,6 @@ test: roleattributes
 test: create_am
 test: hash_func
 test: sanity_check
-test: fsm
 test: errors
 test: select
 test: select_into

src/test/regress/sql/fsm.sql

@@ -1,15 +1,40 @@
 --
 -- Free Space Map test
 --
+SELECT current_setting('block_size')::integer AS blocksize,
+current_setting('block_size')::integer / 8 AS strsize
+\gset
 
 CREATE TABLE fsm_check_size (num int, str text);
 
--- With one block, there should be no FSM
-INSERT INTO fsm_check_size VALUES(1, 'a');
+-- Fill 3 blocks with one record each
+ALTER TABLE fsm_check_size SET (fillfactor=15);
+INSERT INTO fsm_check_size SELECT i, rpad('', :strsize, 'a')
+FROM generate_series(1,3) i;
 
+-- There should be no FSM
 VACUUM fsm_check_size;
-SELECT pg_relation_size('fsm_check_size', 'main') AS heap_size,
-pg_relation_size('fsm_check_size', 'fsm') AS fsm_size;
+SELECT pg_relation_size('fsm_check_size', 'main') / :blocksize AS heap_nblocks,
+pg_relation_size('fsm_check_size', 'fsm') / :blocksize AS fsm_nblocks;
+
+-- The following operations are for testing the functionality of the local
+-- in-memory map. In particular, we want to be able to insert into some
+-- other block than the one at the end of the heap, without using a FSM.
+
+-- Fill most of the last block
+ALTER TABLE fsm_check_size SET (fillfactor=100);
+INSERT INTO fsm_check_size SELECT i, rpad('', :strsize, 'a')
+FROM generate_series(101,105) i;
+
+-- Make sure records can go into any block but the last one
+ALTER TABLE fsm_check_size SET (fillfactor=30);
+
+-- Insert large record and make sure it does not cause the relation to extend
+INSERT INTO fsm_check_size VALUES (111, rpad('', :strsize, 'a'));
+
+VACUUM fsm_check_size;
+SELECT pg_relation_size('fsm_check_size', 'main') / :blocksize AS heap_nblocks,
+pg_relation_size('fsm_check_size', 'fsm') / :blocksize AS fsm_nblocks;
 
 -- Extend table with enough blocks to exceed the FSM threshold
 DO $$
@@ -26,16 +51,16 @@ END;
 $$;
 
 VACUUM fsm_check_size;
-SELECT pg_relation_size('fsm_check_size', 'fsm') AS fsm_size;
+SELECT pg_relation_size('fsm_check_size', 'fsm') / :blocksize AS fsm_nblocks;
 
 -- Add long random string to extend TOAST table to 1 block
 INSERT INTO fsm_check_size
 VALUES(0, (SELECT string_agg(md5(chr(i)), '')
-		   FROM generate_series(1,100) i));
+		   FROM generate_series(1, :blocksize / 100) i));
 
 VACUUM fsm_check_size;
-SELECT pg_relation_size(reltoastrelid, 'main') AS toast_size,
-pg_relation_size(reltoastrelid, 'fsm') AS toast_fsm_size
+SELECT pg_relation_size(reltoastrelid, 'main') / :blocksize AS toast_nblocks,
+pg_relation_size(reltoastrelid, 'fsm') / :blocksize AS toast_fsm_nblocks
 FROM pg_class WHERE relname = 'fsm_check_size';
 
 DROP TABLE fsm_check_size;