Parsed test spec with 2 sessions

starting permutation: s1_plans
step s1_plans: 
	EXPLAIN (COSTS OFF) SELECT count(*) FROM sk WHERE c = 1;
	SET enable_bitmapscan = off;
	EXPLAIN (COSTS OFF) SELECT sum(id) FROM sk WHERE c = 1;
	EXPLAIN (COSTS OFF) SELECT sum(id) FROM sk WHERE k = 1;
	SET pg_lion.enable_plain_scan = off;
	SET pg_lion.pushdown_margin = 1000;
	SET enable_indexonlyscan = off;
	EXPLAIN (COSTS OFF) SELECT id FROM sk WHERE c = 1 ORDER BY id LIMIT 3;
	RESET pg_lion.enable_plain_scan;
	RESET pg_lion.pushdown_margin;
	RESET enable_bitmapscan;
	RESET enable_indexonlyscan;
	SET enable_indexscan = off;
	EXPLAIN (COSTS OFF) SELECT sum(id) FROM sk WHERE c = 1;
	EXPLAIN (COSTS OFF) SELECT sum(id) FROM sk WHERE k = 1;
	RESET enable_indexscan;
	SET enable_hashjoin = off;
	SET enable_mergejoin = off;
	SET enable_nestloop = off;
	EXPLAIN (COSTS OFF) SELECT count(*) FROM skd WHERE pk BETWEEN 1 AND 2
	  AND EXISTS (SELECT 1 FROM sk WHERE sk.c = skd.pk);
	RESET enable_hashjoin;
	RESET enable_mergejoin;
	RESET enable_nestloop;
	EXPLAIN (COSTS OFF) SELECT count(*) FROM sk WHERE c BETWEEN 1 AND 3;
	EXPLAIN (COSTS OFF) SELECT count(*) FROM sk WHERE c IN (1, 3);
	EXPLAIN (COSTS OFF) SELECT count(*) FROM sk WHERE k = 1;
	EXPLAIN (COSTS OFF) SELECT count(*) FROM sk WHERE k BETWEEN 1 AND 3;

QUERY PLAN                  
----------------------------
Custom Scan (LionCount)     
  Lion Indexes: sk_c (c = 1)
(2 rows)

QUERY PLAN                       
---------------------------------
Aggregate                        
  ->  Index Scan using sk_c on sk
        Index Cond: (c = 1)      
(3 rows)

QUERY PLAN                       
---------------------------------
Aggregate                        
  ->  Index Scan using sk_k on sk
        Index Cond: (k = 1)      
(3 rows)

QUERY PLAN                           
-------------------------------------
Limit                                
  ->  Custom Scan (LionOrdered) on sk
        Ordered By: sk_id            
        Lion Cond: (c = 1)           
        Lion Indexes: sk_c           
(5 rows)

QUERY PLAN                           
-------------------------------------
Aggregate                            
  ->  Bitmap Heap Scan on sk         
        Recheck Cond: (c = 1)        
        ->  Bitmap Index Scan on sk_c
              Index Cond: (c = 1)    
(5 rows)

QUERY PLAN                           
-------------------------------------
Aggregate                            
  ->  Bitmap Heap Scan on sk         
        Recheck Cond: (k = 1)        
        ->  Bitmap Index Scan on sk_k
              Index Cond: (k = 1)    
(5 rows)

QUERY PLAN                                               
---------------------------------------------------------
Aggregate                                                
  ->  Custom Scan (LionSemiJoin)                         
        Lion Indexes: sk_c (c = skd.pk)                  
        Join Rows: the outer rows with a match           
        ->  Bitmap Heap Scan on skd                      
              Recheck Cond: ((pk >= 1) AND (pk <= 2))    
              ->  Bitmap Index Scan on skd_pkey          
                    Index Cond: ((pk >= 1) AND (pk <= 2))
(8 rows)

QUERY PLAN                              
----------------------------------------
Custom Scan (LionCount)                 
  Lion Indexes: sk_c (c >= 1 AND c <= 3)
(2 rows)

QUERY PLAN                                         
---------------------------------------------------
Custom Scan (LionCount)                            
  Lion Indexes: sk_c (c = ANY ('{1,3}'::integer[]))
(2 rows)

QUERY PLAN                  
----------------------------
Custom Scan (LionCount)     
  Lion Indexes: sk_k (k = 1)
(2 rows)

QUERY PLAN                              
----------------------------------------
Custom Scan (LionCount)                 
  Lion Indexes: sk_k (k >= 1 AND k <= 3)
(2 rows)


starting permutation: s1_begin s2_begin s1_count s2_count s1_other s2_other s1_commit s2_commit
step s1_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s2_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s1_count: SELECT count(*) FROM sk WHERE c = 1;
count
-----
  400
(1 row)

step s2_count: SELECT count(*) FROM sk WHERE c = 125;
count
-----
  400
(1 row)

step s1_other: INSERT INTO sk VALUES (200001, 200, 4000);
step s2_other: INSERT INTO sk VALUES (200002, 60, 1000);
step s1_commit: COMMIT;
step s2_commit: COMMIT;

starting permutation: s1_begin s2_begin s1_count s2_count s1_skew s2_skew s1_commit s2_commit
step s1_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s2_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s1_count: SELECT count(*) FROM sk WHERE c = 1;
count
-----
  400
(1 row)

step s2_count: SELECT count(*) FROM sk WHERE c = 125;
count
-----
  400
(1 row)

step s1_skew: INSERT INTO sk VALUES (200001, 125, 2500);
step s2_skew: INSERT INTO sk VALUES (200002, 1, 1);
step s1_commit: COMMIT;
step s2_commit: COMMIT;
ERROR:  could not serialize access due to read/write dependencies among transactions

starting permutation: s1_begin s2_begin s1_func s2_func s1_other s2_other s1_commit s2_commit
step s1_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s2_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s1_func: SELECT lion_index_count('sk_c', 1);
lion_index_count
----------------
             400
(1 row)

step s2_func: SELECT lion_index_count('sk_c', 125);
lion_index_count
----------------
             400
(1 row)

step s1_other: INSERT INTO sk VALUES (200001, 200, 4000);
step s2_other: INSERT INTO sk VALUES (200002, 60, 1000);
step s1_commit: COMMIT;
step s2_commit: COMMIT;

starting permutation: s1_begin s2_begin s1_func s2_func s1_skew s2_skew s1_commit s2_commit
step s1_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s2_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s1_func: SELECT lion_index_count('sk_c', 1);
lion_index_count
----------------
             400
(1 row)

step s2_func: SELECT lion_index_count('sk_c', 125);
lion_index_count
----------------
             400
(1 row)

step s1_skew: INSERT INTO sk VALUES (200001, 125, 2500);
step s2_skew: INSERT INTO sk VALUES (200002, 1, 1);
step s1_commit: COMMIT;
step s2_commit: COMMIT;
ERROR:  could not serialize access due to read/write dependencies among transactions

starting permutation: s1_begin s2_begin s1_idx s2_idx s1_other s2_other s1_commit s2_commit
step s1_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s2_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s1_idx: SET LOCAL enable_bitmapscan = off; SELECT sum(id) FROM sk WHERE c = 1;
   sum
------
798400
(1 row)

step s2_idx: SET LOCAL enable_bitmapscan = off; SELECT sum(id) FROM sk WHERE c = 125;
     sum
--------
20000000
(1 row)

step s1_other: INSERT INTO sk VALUES (200001, 200, 4000);
step s2_other: INSERT INTO sk VALUES (200002, 60, 1000);
step s1_commit: COMMIT;
step s2_commit: COMMIT;

starting permutation: s1_begin s2_begin s1_idx s2_idx s1_skew s2_skew s1_commit s2_commit
step s1_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s2_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s1_idx: SET LOCAL enable_bitmapscan = off; SELECT sum(id) FROM sk WHERE c = 1;
   sum
------
798400
(1 row)

step s2_idx: SET LOCAL enable_bitmapscan = off; SELECT sum(id) FROM sk WHERE c = 125;
     sum
--------
20000000
(1 row)

step s1_skew: INSERT INTO sk VALUES (200001, 125, 2500);
step s2_skew: INSERT INTO sk VALUES (200002, 1, 1);
step s1_commit: COMMIT;
step s2_commit: COMMIT;
ERROR:  could not serialize access due to read/write dependencies among transactions

starting permutation: s1_begin s2_begin s1_bmp s2_bmp s1_other s2_other s1_commit s2_commit
step s1_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s2_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s1_bmp: SET LOCAL enable_indexscan = off; SELECT sum(id) FROM sk WHERE c = 1;
   sum
------
798400
(1 row)

step s2_bmp: SET LOCAL enable_indexscan = off; SELECT sum(id) FROM sk WHERE c = 125;
     sum
--------
20000000
(1 row)

step s1_other: INSERT INTO sk VALUES (200001, 200, 4000);
step s2_other: INSERT INTO sk VALUES (200002, 60, 1000);
step s1_commit: COMMIT;
step s2_commit: COMMIT;

starting permutation: s1_begin s2_begin s1_bmp s2_bmp s1_skew s2_skew s1_commit s2_commit
step s1_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s2_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s1_bmp: SET LOCAL enable_indexscan = off; SELECT sum(id) FROM sk WHERE c = 1;
   sum
------
798400
(1 row)

step s2_bmp: SET LOCAL enable_indexscan = off; SELECT sum(id) FROM sk WHERE c = 125;
     sum
--------
20000000
(1 row)

step s1_skew: INSERT INTO sk VALUES (200001, 125, 2500);
step s2_skew: INSERT INTO sk VALUES (200002, 1, 1);
step s1_commit: COMMIT;
step s2_commit: COMMIT;
ERROR:  could not serialize access due to read/write dependencies among transactions

starting permutation: s1_begin s2_begin s1_ord s2_ord s1_other s2_other s1_commit s2_commit
step s1_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s2_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s1_ord: SET LOCAL enable_bitmapscan = off; SET LOCAL pg_lion.enable_plain_scan = off;
				  SET LOCAL pg_lion.pushdown_margin = 1000; SET LOCAL enable_indexonlyscan = off;
				  SELECT id FROM sk WHERE c = 1 ORDER BY id LIMIT 3;
id
--
 1
11
21
(3 rows)

step s2_ord: SET LOCAL enable_bitmapscan = off; SET LOCAL pg_lion.enable_plain_scan = off;
				  SET LOCAL pg_lion.pushdown_margin = 1000; SET LOCAL enable_indexonlyscan = off;
				  SELECT id FROM sk WHERE c = 125 ORDER BY id LIMIT 3;
   id
-----
48005
48015
48025
(3 rows)

step s1_other: INSERT INTO sk VALUES (200001, 200, 4000);
step s2_other: INSERT INTO sk VALUES (200002, 60, 1000);
step s1_commit: COMMIT;
step s2_commit: COMMIT;

starting permutation: s1_begin s2_begin s1_ord s2_ord s1_skew s2_skew s1_commit s2_commit
step s1_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s2_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s1_ord: SET LOCAL enable_bitmapscan = off; SET LOCAL pg_lion.enable_plain_scan = off;
				  SET LOCAL pg_lion.pushdown_margin = 1000; SET LOCAL enable_indexonlyscan = off;
				  SELECT id FROM sk WHERE c = 1 ORDER BY id LIMIT 3;
id
--
 1
11
21
(3 rows)

step s2_ord: SET LOCAL enable_bitmapscan = off; SET LOCAL pg_lion.enable_plain_scan = off;
				  SET LOCAL pg_lion.pushdown_margin = 1000; SET LOCAL enable_indexonlyscan = off;
				  SELECT id FROM sk WHERE c = 125 ORDER BY id LIMIT 3;
   id
-----
48005
48015
48025
(3 rows)

step s1_skew: INSERT INTO sk VALUES (200001, 125, 2500);
step s2_skew: INSERT INTO sk VALUES (200002, 1, 1);
step s1_commit: COMMIT;
step s2_commit: COMMIT;
ERROR:  could not serialize access due to read/write dependencies among transactions

starting permutation: s1_begin s2_begin s1_semi s2_semi s1_other s2_other s1_commit s2_commit
step s1_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s2_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s1_semi: SET LOCAL enable_hashjoin = off; SET LOCAL enable_mergejoin = off;
				  SET LOCAL enable_nestloop = off;
				  SELECT count(*) FROM skd WHERE pk BETWEEN 1 AND 2
				    AND EXISTS (SELECT 1 FROM sk WHERE sk.c = skd.pk);
count
-----
    2
(1 row)

step s2_semi: SET LOCAL enable_hashjoin = off; SET LOCAL enable_mergejoin = off;
				  SET LOCAL enable_nestloop = off;
				  SELECT count(*) FROM skd WHERE pk BETWEEN 125 AND 126
				    AND EXISTS (SELECT 1 FROM sk WHERE sk.c = skd.pk);
count
-----
    2
(1 row)

step s1_other: INSERT INTO sk VALUES (200001, 200, 4000);
step s2_other: INSERT INTO sk VALUES (200002, 60, 1000);
step s1_commit: COMMIT;
step s2_commit: COMMIT;

starting permutation: s1_begin s2_begin s1_semi s2_semi s1_skew s2_skew s1_commit s2_commit
step s1_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s2_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s1_semi: SET LOCAL enable_hashjoin = off; SET LOCAL enable_mergejoin = off;
				  SET LOCAL enable_nestloop = off;
				  SELECT count(*) FROM skd WHERE pk BETWEEN 1 AND 2
				    AND EXISTS (SELECT 1 FROM sk WHERE sk.c = skd.pk);
count
-----
    2
(1 row)

step s2_semi: SET LOCAL enable_hashjoin = off; SET LOCAL enable_mergejoin = off;
				  SET LOCAL enable_nestloop = off;
				  SELECT count(*) FROM skd WHERE pk BETWEEN 125 AND 126
				    AND EXISTS (SELECT 1 FROM sk WHERE sk.c = skd.pk);
count
-----
    2
(1 row)

step s1_skew: INSERT INTO sk VALUES (200001, 125, 2500);
step s2_skew: INSERT INTO sk VALUES (200002, 1, 1);
step s1_commit: COMMIT;
step s2_commit: COMMIT;
ERROR:  could not serialize access due to read/write dependencies among transactions

starting permutation: s1_begin s2_begin s1_range s2_range s1_other s2_other s1_commit s2_commit
step s1_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s2_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s1_range: SELECT count(*) FROM sk WHERE c BETWEEN 1 AND 3;
count
-----
 1200
(1 row)

step s2_range: SELECT count(*) FROM sk WHERE c BETWEEN 125 AND 127;
count
-----
 1200
(1 row)

step s1_other: INSERT INTO sk VALUES (200001, 200, 4000);
step s2_other: INSERT INTO sk VALUES (200002, 60, 1000);
step s1_commit: COMMIT;
step s2_commit: COMMIT;

starting permutation: s1_begin s2_begin s1_range s2_range s1_skew s2_skew s1_commit s2_commit
step s1_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s2_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s1_range: SELECT count(*) FROM sk WHERE c BETWEEN 1 AND 3;
count
-----
 1200
(1 row)

step s2_range: SELECT count(*) FROM sk WHERE c BETWEEN 125 AND 127;
count
-----
 1200
(1 row)

step s1_skew: INSERT INTO sk VALUES (200001, 125, 2500);
step s2_skew: INSERT INTO sk VALUES (200002, 1, 1);
step s1_commit: COMMIT;
step s2_commit: COMMIT;
ERROR:  could not serialize access due to read/write dependencies among transactions

starting permutation: s1_begin s2_begin s1_in s2_in s1_other s2_other s1_commit s2_commit
step s1_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s2_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s1_in: SELECT count(*) FROM sk WHERE c IN (1, 3);
count
-----
  800
(1 row)

step s2_in: SELECT count(*) FROM sk WHERE c IN (125, 127);
count
-----
  800
(1 row)

step s1_other: INSERT INTO sk VALUES (200001, 200, 4000);
step s2_other: INSERT INTO sk VALUES (200002, 60, 1000);
step s1_commit: COMMIT;
step s2_commit: COMMIT;

starting permutation: s1_begin s2_begin s1_in s2_in s1_skew s2_skew s1_commit s2_commit
step s1_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s2_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s1_in: SELECT count(*) FROM sk WHERE c IN (1, 3);
count
-----
  800
(1 row)

step s2_in: SELECT count(*) FROM sk WHERE c IN (125, 127);
count
-----
  800
(1 row)

step s1_skew: INSERT INTO sk VALUES (200001, 125, 2500);
step s2_skew: INSERT INTO sk VALUES (200002, 1, 1);
step s1_commit: COMMIT;
step s2_commit: COMMIT;
ERROR:  could not serialize access due to read/write dependencies among transactions

starting permutation: s1_begin s2_begin s1_kcount s2_kcount s1_other s2_other s1_commit s2_commit
step s1_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s2_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s1_kcount: SELECT count(*) FROM sk WHERE k = 1;
count
-----
   20
(1 row)

step s2_kcount: SELECT count(*) FROM sk WHERE k = 2500;
count
-----
   20
(1 row)

step s1_other: INSERT INTO sk VALUES (200001, 200, 4000);
step s2_other: INSERT INTO sk VALUES (200002, 60, 1000);
step s1_commit: COMMIT;
step s2_commit: COMMIT;

starting permutation: s1_begin s2_begin s1_kcount s2_kcount s1_skew s2_skew s1_commit s2_commit
step s1_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s2_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s1_kcount: SELECT count(*) FROM sk WHERE k = 1;
count
-----
   20
(1 row)

step s2_kcount: SELECT count(*) FROM sk WHERE k = 2500;
count
-----
   20
(1 row)

step s1_skew: INSERT INTO sk VALUES (200001, 125, 2500);
step s2_skew: INSERT INTO sk VALUES (200002, 1, 1);
step s1_commit: COMMIT;
step s2_commit: COMMIT;
ERROR:  could not serialize access due to read/write dependencies among transactions

starting permutation: s1_begin s2_begin s1_kidx s2_kidx s1_other s2_other s1_commit s2_commit
step s1_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s2_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s1_kidx: SET LOCAL enable_bitmapscan = off; SELECT sum(id) FROM sk WHERE k = 1;
   sum
------
950020
(1 row)

step s2_kidx: SET LOCAL enable_bitmapscan = off; SELECT sum(id) FROM sk WHERE k = 2500;
    sum
-------
1000000
(1 row)

step s1_other: INSERT INTO sk VALUES (200001, 200, 4000);
step s2_other: INSERT INTO sk VALUES (200002, 60, 1000);
step s1_commit: COMMIT;
step s2_commit: COMMIT;

starting permutation: s1_begin s2_begin s1_kidx s2_kidx s1_skew s2_skew s1_commit s2_commit
step s1_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s2_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s1_kidx: SET LOCAL enable_bitmapscan = off; SELECT sum(id) FROM sk WHERE k = 1;
   sum
------
950020
(1 row)

step s2_kidx: SET LOCAL enable_bitmapscan = off; SELECT sum(id) FROM sk WHERE k = 2500;
    sum
-------
1000000
(1 row)

step s1_skew: INSERT INTO sk VALUES (200001, 125, 2500);
step s2_skew: INSERT INTO sk VALUES (200002, 1, 1);
step s1_commit: COMMIT;
step s2_commit: COMMIT;
ERROR:  could not serialize access due to read/write dependencies among transactions

starting permutation: s1_begin s2_begin s1_kbmp s2_kbmp s1_other s2_other s1_commit s2_commit
step s1_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s2_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s1_kbmp: SET LOCAL enable_indexscan = off; SELECT sum(id) FROM sk WHERE k = 1;
   sum
------
950020
(1 row)

step s2_kbmp: SET LOCAL enable_indexscan = off; SELECT sum(id) FROM sk WHERE k = 2500;
    sum
-------
1000000
(1 row)

step s1_other: INSERT INTO sk VALUES (200001, 200, 4000);
step s2_other: INSERT INTO sk VALUES (200002, 60, 1000);
step s1_commit: COMMIT;
step s2_commit: COMMIT;

starting permutation: s1_begin s2_begin s1_kbmp s2_kbmp s1_skew s2_skew s1_commit s2_commit
step s1_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s2_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s1_kbmp: SET LOCAL enable_indexscan = off; SELECT sum(id) FROM sk WHERE k = 1;
   sum
------
950020
(1 row)

step s2_kbmp: SET LOCAL enable_indexscan = off; SELECT sum(id) FROM sk WHERE k = 2500;
    sum
-------
1000000
(1 row)

step s1_skew: INSERT INTO sk VALUES (200001, 125, 2500);
step s2_skew: INSERT INTO sk VALUES (200002, 1, 1);
step s1_commit: COMMIT;
step s2_commit: COMMIT;
ERROR:  could not serialize access due to read/write dependencies among transactions

starting permutation: s1_begin s2_begin s1_krange s2_krange s1_other s2_other s1_commit s2_commit
step s1_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s2_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s1_krange: SELECT count(*) FROM sk WHERE k BETWEEN 1 AND 3;
count
-----
   60
(1 row)

step s2_krange: SELECT count(*) FROM sk WHERE k BETWEEN 2500 AND 2502;
count
-----
   60
(1 row)

step s1_other: INSERT INTO sk VALUES (200001, 200, 4000);
step s2_other: INSERT INTO sk VALUES (200002, 60, 1000);
step s1_commit: COMMIT;
step s2_commit: COMMIT;

starting permutation: s1_begin s2_begin s1_krange s2_krange s1_skew s2_skew s1_commit s2_commit
step s1_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s2_begin: BEGIN ISOLATION LEVEL SERIALIZABLE;
step s1_krange: SELECT count(*) FROM sk WHERE k BETWEEN 1 AND 3;
count
-----
   60
(1 row)

step s2_krange: SELECT count(*) FROM sk WHERE k BETWEEN 2500 AND 2502;
count
-----
   60
(1 row)

step s1_skew: INSERT INTO sk VALUES (200001, 125, 2500);
step s2_skew: INSERT INTO sk VALUES (200002, 1, 1);
step s1_commit: COMMIT;
step s2_commit: COMMIT;
ERROR:  could not serialize access due to read/write dependencies among transactions