select * from information_schema.engines where engine = 'xengine';
ENGINE	SUPPORT	COMMENT	TRANSACTIONS	XA	SAVEPOINTS
XENGINE	DEFAULT	X-Engine storage engine	YES	YES	YES
drop table if exists t0,t1,t2,t3;
create table t0 (a int) engine=myisam;
insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
create table t1(a int) engine=myisam;
insert into t1 select A.a + B.a* 10 + C.a * 100 from t0 A, t0 B, t0 C;
create table t2 (
pk int primary key,
kp1 int,
kp2 int,
col1 int,
key (kp1,kp2) comment 'cf1'
) engine=xengine;
insert into t2 select a,a,a,a from t1;
# Try a basic case:
explain
select * from t2 where kp1 between 1 and 10 and mod(kp2,2)=0;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t2	NULL	range	kp1	kp1	5	NULL	#	100.00	Using index condition
Warnings:
Note	1003	/* select#1 */ select `test`.`t2`.`pk` AS `pk`,`test`.`t2`.`kp1` AS `kp1`,`test`.`t2`.`kp2` AS `kp2`,`test`.`t2`.`col1` AS `col1` from `test`.`t2` where ((`test`.`t2`.`kp1` between 1 and 10) and ((`test`.`t2`.`kp2` % 2) = 0))
select * from t2 where kp1 between 1 and 10 and mod(kp2,2)=0;
pk	kp1	kp2	col1
2	2	2	2
4	4	4	4
6	6	6	6
8	8	8	8
10	10	10	10
# Check that ICP doesnt work for columns where column value
# cant be restored from mem-comparable form:
create table t3 (
pk int primary key,
kp1 int,
kp2 varchar(10) collate utf8_general_ci,
col1 int,
key (kp1,kp2) comment 'cf1'
) engine=xengine;
Warnings:
Warning	3778	'utf8_general_ci' is a collation of the deprecated character set UTF8MB3. Please consider using UTF8MB4 with an appropriate collation instead.
# This must not use ICP:
explain
select * from t3 where kp1=3 and kp2 like '%foo%';
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t3	NULL	ref	kp1	kp1	5	const	#	100.00	Using index condition
Warnings:
Note	1003	/* select#1 */ select `test`.`t3`.`pk` AS `pk`,`test`.`t3`.`kp1` AS `kp1`,`test`.`t3`.`kp2` AS `kp2`,`test`.`t3`.`col1` AS `col1` from `test`.`t3` where ((`test`.`t3`.`kp1` = 3) and (`test`.`t3`.`kp2` like '%foo%'))
select * from t3 where kp1=3 and kp2 like '%foo%';
pk	kp1	kp2	col1
explain format=json
select * from t3 where kp1 between 2 and 4 and mod(kp1,3)=0 and kp2 like '%foo%';
EXPLAIN
{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "0.71"
    },
    "table": {
      "table_name": "t3",
      "access_type": "range",
      "possible_keys": [
        "kp1"
      ],
      "key": "kp1",
      "used_key_parts": [
        "kp1"
      ],
      "key_length": "5",
      "rows_examined_per_scan": 1,
      "rows_produced_per_join": 1,
      "filtered": "100.00",
      "index_condition": "((`test`.`t3`.`kp1` between 2 and 4) and ((`test`.`t3`.`kp1` % 3) = 0) and (`test`.`t3`.`kp2` like '%foo%'))",
      "cost_info": {
        "read_cost": "0.61",
        "eval_cost": "0.10",
        "prefix_cost": "0.71",
        "data_read_per_join": "48"
      },
      "used_columns": [
        "pk",
        "kp1",
        "kp2",
        "col1"
      ]
    }
  }
}
Warnings:
Note	1003	/* select#1 */ select `test`.`t3`.`pk` AS `pk`,`test`.`t3`.`kp1` AS `kp1`,`test`.`t3`.`kp2` AS `kp2`,`test`.`t3`.`col1` AS `col1` from `test`.`t3` where ((`test`.`t3`.`kp1` between 2 and 4) and ((`test`.`t3`.`kp1` % 3) = 0) and (`test`.`t3`.`kp2` like '%foo%'))
# Check that we handle the case where out-of-range is encountered sooner
# than matched index condition
explain
select * from t2 where kp1< 3 and kp2+1>50000;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t2	NULL	range	kp1	kp1	5	NULL	#	100.00	Using index condition
Warnings:
Note	1003	/* select#1 */ select `test`.`t2`.`pk` AS `pk`,`test`.`t2`.`kp1` AS `kp1`,`test`.`t2`.`kp2` AS `kp2`,`test`.`t2`.`col1` AS `col1` from `test`.`t2` where ((`test`.`t2`.`kp1` < 3) and ((`test`.`t2`.`kp2` + 1) > 50000))
select * from t2 where kp1< 3 and kp2+1>50000;
pk	kp1	kp2	col1
explain
select * from t2 where kp1< 3 and kp2+1>50000;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t2	NULL	range	kp1	kp1	5	NULL	#	100.00	Using index condition
Warnings:
Note	1003	/* select#1 */ select `test`.`t2`.`pk` AS `pk`,`test`.`t2`.`kp1` AS `kp1`,`test`.`t2`.`kp2` AS `kp2`,`test`.`t2`.`col1` AS `col1` from `test`.`t2` where ((`test`.`t2`.`kp1` < 3) and ((`test`.`t2`.`kp2` + 1) > 50000))
select * from t2 where kp1< 3 and kp2+1>50000;
pk	kp1	kp2	col1
# Try doing backwards scans
explain
select * from t2 where kp1 between 1 and 10 and mod(kp2,2)=0 order by kp1 desc;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t2	NULL	range	kp1	kp1	5	NULL	#	100.00	Using index condition; Backward index scan
Warnings:
Note	1003	/* select#1 */ select `test`.`t2`.`pk` AS `pk`,`test`.`t2`.`kp1` AS `kp1`,`test`.`t2`.`kp2` AS `kp2`,`test`.`t2`.`col1` AS `col1` from `test`.`t2` where ((`test`.`t2`.`kp1` between 1 and 10) and ((`test`.`t2`.`kp2` % 2) = 0)) order by `test`.`t2`.`kp1` desc
select * from t2 where kp1 between 1 and 10 and mod(kp2,2)=0 order by kp1 desc;
pk	kp1	kp2	col1
10	10	10	10
8	8	8	8
6	6	6	6
4	4	4	4
2	2	2	2
explain
select * from t2 where kp1 >990 and mod(kp2,2)=0 order by kp1 desc;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t2	NULL	range	kp1	kp1	5	NULL	#	100.00	Using index condition; Backward index scan
Warnings:
Note	1003	/* select#1 */ select `test`.`t2`.`pk` AS `pk`,`test`.`t2`.`kp1` AS `kp1`,`test`.`t2`.`kp2` AS `kp2`,`test`.`t2`.`col1` AS `col1` from `test`.`t2` where ((`test`.`t2`.`kp1` > 990) and ((`test`.`t2`.`kp2` % 2) = 0)) order by `test`.`t2`.`kp1` desc
select * from t2 where kp1 >990 and mod(kp2,2)=0 order by kp1 desc;
pk	kp1	kp2	col1
998	998	998	998
996	996	996	996
994	994	994	994
992	992	992	992
explain
select * from t2 where kp1< 3 and kp2+1>50000 order by kp1 desc;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t2	NULL	range	kp1	kp1	5	NULL	#	100.00	Using index condition; Backward index scan
Warnings:
Note	1003	/* select#1 */ select `test`.`t2`.`pk` AS `pk`,`test`.`t2`.`kp1` AS `kp1`,`test`.`t2`.`kp2` AS `kp2`,`test`.`t2`.`col1` AS `col1` from `test`.`t2` where ((`test`.`t2`.`kp1` < 3) and ((`test`.`t2`.`kp2` + 1) > 50000)) order by `test`.`t2`.`kp1` desc
select * from t2 where kp1< 3 and kp2+1>50000 order by kp1 desc;
pk	kp1	kp2	col1
drop table t0,t1,t2,t3;
#
# Check how ICP affects counters
#
# First, some preparations
#
create table t4 (
id int,
id1 int,
id2 int,
value int,
value2 varchar(100),
primary key (id),
key id1_id2 (id1, id2) comment 'cf1'
) engine=xengine charset=latin1 collate latin1_bin;
insert into t4 values
(1,1,1,1,1), (2,1,2,2,2), (3,1,3,3,3),(4,1,4,4,4),(5,1,5,5,5),
(6,1,6,6,6), (7,1,7,7,7), (8,1,8,8,8),(9,1,9,9,9),(10,1,10,10,10);
#
# Now, the test itself
#
# ============== index-only query ==============
explain
select id1,id2 from t4 force index (id1_id2) where id1=1 and id2 % 10 = 1;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t4	NULL	ref	id1_id2	id1_id2	5	const	#	100.00	Using where; Using index
Warnings:
Note	1003	/* select#1 */ select `test`.`t4`.`id1` AS `id1`,`test`.`t4`.`id2` AS `id2` from `test`.`t4` FORCE INDEX (`id1_id2`) where ((`test`.`t4`.`id1` = 1) and ((`test`.`t4`.`id2` % 10) = 1))
select id1,id2 from t4 force index (id1_id2) where id1=1 and id2 % 10 = 1;
id1	id2
1	1
# ============== Query without ICP ==============
set optimizer_switch='index_condition_pushdown=off';
explain
select * from t4 force index (id1_id2) where id1=1 and id2 % 10 = 1;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t4	NULL	ref	id1_id2	id1_id2	5	const	#	100.00	Using where
Warnings:
Note	1003	/* select#1 */ select `test`.`t4`.`id` AS `id`,`test`.`t4`.`id1` AS `id1`,`test`.`t4`.`id2` AS `id2`,`test`.`t4`.`value` AS `value`,`test`.`t4`.`value2` AS `value2` from `test`.`t4` FORCE INDEX (`id1_id2`) where ((`test`.`t4`.`id1` = 1) and ((`test`.`t4`.`id2` % 10) = 1))
select * from t4 force index (id1_id2) where id1=1 and id2 % 10 = 1;
id	id1	id2	value	value2
1	1	1	1	1
# ============== Query with ICP ==============
set optimizer_switch='index_condition_pushdown=on';
explain
select * from t4 force index (id1_id2) where id1=1 and id2 % 10 = 1;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t4	NULL	ref	id1_id2	id1_id2	5	const	#	100.00	Using index condition
Warnings:
Note	1003	/* select#1 */ select `test`.`t4`.`id` AS `id`,`test`.`t4`.`id1` AS `id1`,`test`.`t4`.`id2` AS `id2`,`test`.`t4`.`value` AS `value`,`test`.`t4`.`value2` AS `value2` from `test`.`t4` FORCE INDEX (`id1_id2`) where ((`test`.`t4`.`id1` = 1) and ((`test`.`t4`.`id2` % 10) = 1))
select * from t4 force index (id1_id2) where id1=1 and id2 % 10 = 1;
id	id1	id2	value	value2
1	1	1	1	1
drop table t4;
#
# Issue #67: Inefficient index condition pushdown
#
create table t0 (a int);
insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
create table t1 (
pk int not null primary key,
key1 bigint(20) unsigned,
col1 int,
key (key1)
) engine=xengine;
Warnings:
Warning	1681	Integer display width is deprecated and will be removed in a future release.
insert into t1
select
A.a+10*B.a+100*C.a,
A.a+10*B.a+100*C.a,
1234
from t0 A, t0 B, t0 C;
set @count=0;
explain
select * from t1 where key1=1;
id	select_type	table	partitions	type	possible_keys	key	key_len	ref	rows	filtered	Extra
1	SIMPLE	t1	NULL	ref	key1	key1	9	const	#	100.00	NULL
Warnings:
Note	1003	/* select#1 */ select `test`.`t1`.`pk` AS `pk`,`test`.`t1`.`key1` AS `key1`,`test`.`t1`.`col1` AS `col1` from `test`.`t1` where (`test`.`t1`.`key1` = 1)
set @count_diff =(select (value - @count) from information_schema.xengine_perf_context
where table_schema=database() and table_name='t1' and stat_type='INTERNAL_KEY_SKIPPED_COUNT');
select * from t1 where key1=1;
pk	key1	col1
1	1	1234
set @count_diff =(select (value - @count) from information_schema.xengine_perf_context
where table_schema=database() and table_name='t1' and stat_type='INTERNAL_KEY_SKIPPED_COUNT');
# The following must be =1, or in any case not 999:
select @count_diff as "INTERNAL_KEY_SKIPPED_COUNT increment";
INTERNAL_KEY_SKIPPED_COUNT increment
NULL
drop table t0,t1;