Revert "Avoid creation of the free space map for small heap relations."

This reverts commit ac88d2962a.

src/test/regress/expected/fsm.out

@@ -1,75 +0,0 @@
---
--- Free Space Map test
---
-CREATE TABLE fsm_check_size (num int, str text);
--- Fill 3 blocks with as many large records as will fit
--- No FSM
-INSERT INTO fsm_check_size SELECT i, rpad('', 1024, 'a')
-FROM generate_series(1,7*3) i;
-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 
------------+----------
-     24576 |        0
-(1 row)
-
--- Clear some space on block 0
-DELETE FROM fsm_check_size WHERE num <= 5;
-VACUUM fsm_check_size;
--- Insert small record in block 2 to set the cached smgr targetBlock
-INSERT INTO fsm_check_size VALUES(99, 'b');
--- Insert large record and make sure it goes in block 0 rather than
--- causing the relation to extend
-INSERT INTO fsm_check_size VALUES (101, rpad('', 1024, 'a'));
-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 
------------+----------
-     24576 |        0
-(1 row)
-
--- Extend table with enough blocks to exceed the FSM threshold
--- FSM is created and extended to 3 blocks
-INSERT INTO fsm_check_size SELECT i, 'c' FROM generate_series(200,1200) i;
-VACUUM fsm_check_size;
-SELECT pg_relation_size('fsm_check_size', 'fsm') AS fsm_size;
- fsm_size 
-----------
-    24576
-(1 row)
-
--- Truncate heap to 1 block
--- No change in FSM
-DELETE FROM fsm_check_size WHERE num > 7;
-VACUUM fsm_check_size;
-SELECT pg_relation_size('fsm_check_size', 'fsm') AS fsm_size;
- fsm_size 
-----------
-    24576
-(1 row)
-
--- Truncate heap to 0 blocks
--- FSM now truncated to 2 blocks
-DELETE FROM fsm_check_size;
-VACUUM fsm_check_size;
-SELECT pg_relation_size('fsm_check_size', 'fsm') AS fsm_size;
- fsm_size 
-----------
-    16384
-(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));
-VACUUM fsm_check_size;
-SELECT pg_relation_size(reltoastrelid, 'main') AS toast_size,
-pg_relation_size(reltoastrelid, 'fsm') AS toast_fsm_size
-FROM pg_class WHERE relname = 'fsm_check_size';
- toast_size | toast_fsm_size 
-------------+----------------
-       8192 |              0
-(1 row)
-
-DROP TABLE fsm_check_size;

src/test/regress/parallel_schedule

@@ -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

@@ -80,7 +80,6 @@ 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

@@ -1,55 +0,0 @@
---
--- Free Space Map test
---
-
-CREATE TABLE fsm_check_size (num int, str text);
-
--- Fill 3 blocks with as many large records as will fit
--- No FSM
-INSERT INTO fsm_check_size SELECT i, rpad('', 1024, 'a')
-FROM generate_series(1,7*3) i;
-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;
-
--- Clear some space on block 0
-DELETE FROM fsm_check_size WHERE num <= 5;
-VACUUM fsm_check_size;
-
--- Insert small record in block 2 to set the cached smgr targetBlock
-INSERT INTO fsm_check_size VALUES(99, 'b');
-
--- Insert large record and make sure it goes in block 0 rather than
--- causing the relation to extend
-INSERT INTO fsm_check_size VALUES (101, rpad('', 1024, 'a'));
-SELECT pg_relation_size('fsm_check_size', 'main') AS heap_size,
-pg_relation_size('fsm_check_size', 'fsm') AS fsm_size;
-
--- Extend table with enough blocks to exceed the FSM threshold
--- FSM is created and extended to 3 blocks
-INSERT INTO fsm_check_size SELECT i, 'c' FROM generate_series(200,1200) i;
-VACUUM fsm_check_size;
-SELECT pg_relation_size('fsm_check_size', 'fsm') AS fsm_size;
-
--- Truncate heap to 1 block
--- No change in FSM
-DELETE FROM fsm_check_size WHERE num > 7;
-VACUUM fsm_check_size;
-SELECT pg_relation_size('fsm_check_size', 'fsm') AS fsm_size;
-
--- Truncate heap to 0 blocks
--- FSM now truncated to 2 blocks
-DELETE FROM fsm_check_size;
-VACUUM fsm_check_size;
-SELECT pg_relation_size('fsm_check_size', 'fsm') AS fsm_size;
-
--- 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));
-VACUUM fsm_check_size;
-SELECT pg_relation_size(reltoastrelid, 'main') AS toast_size,
-pg_relation_size(reltoastrelid, 'fsm') AS toast_fsm_size
-FROM pg_class WHERE relname = 'fsm_check_size';
-
-DROP TABLE fsm_check_size;