CREATE TABLE `access_path_selection` (
`a` int,
`b` int,
KEY `IDX_a` (`a`),
KEY `IDX_b` (`b`),
KEY `IDX_ab` (`a`, `b`)
);
explain format = 'brief' select a from access_path_selection where a < 3;
id	estRows	task	access object	operator info
IndexReader	3323.33	root		index:IndexRangeScan
└─IndexRangeScan	3323.33	cop[tikv]	table:access_path_selection, index:IDX_a(a)	range:[-inf,3), keep order:false, stats:pseudo
explain format = 'brief' select a, b from access_path_selection where a < 3;
id	estRows	task	access object	operator info
IndexReader	3323.33	root		index:IndexRangeScan
└─IndexRangeScan	3323.33	cop[tikv]	table:access_path_selection, index:IDX_ab(a, b)	range:[-inf,3), keep order:false, stats:pseudo
explain format = 'brief' select a, b from access_path_selection where b < 3;
id	estRows	task	access object	operator info
TableReader	3323.33	root		data:Selection
└─Selection	3323.33	cop[tikv]		lt(test.access_path_selection.b, 3)
  └─TableFullScan	10000.00	cop[tikv]	table:access_path_selection	keep order:false, stats:pseudo
explain format = 'brief' select a, b from access_path_selection where a < 3 and b < 3;
id	estRows	task	access object	operator info
IndexReader	1104.45	root		index:Selection
└─Selection	1104.45	cop[tikv]		lt(test.access_path_selection.b, 3)
  └─IndexRangeScan	3323.33	cop[tikv]	table:access_path_selection, index:IDX_ab(a, b)	range:[-inf,3), keep order:false, stats:pseudo
explain format = 'brief' select a, b from access_path_selection where a > 10 order by _tidb_rowid;
id	estRows	task	access object	operator info
Projection	3333.33	root		test.access_path_selection.a, test.access_path_selection.b
└─TableReader	3333.33	root		data:Selection
  └─Selection	3333.33	cop[tikv]		gt(test.access_path_selection.a, 10)
    └─TableFullScan	10000.00	cop[tikv]	table:access_path_selection	keep order:true, stats:pseudo
explain format = 'brief' select max(_tidb_rowid) from access_path_selection;
id	estRows	task	access object	operator info
StreamAgg	1.00	root		funcs:max(test.access_path_selection._tidb_rowid)->Column#4
└─Limit	1.00	root		offset:0, count:1
  └─TableReader	1.00	root		data:Limit
    └─Limit	1.00	cop[tikv]		offset:0, count:1
      └─TableFullScan	1.00	cop[tikv]	table:access_path_selection	keep order:true, desc, stats:pseudo
explain format = 'brief' select count(1) from access_path_selection;
id	estRows	task	access object	operator info
StreamAgg	1.00	root		funcs:count(Column#18)->Column#4
└─TableReader	1.00	root		data:StreamAgg
  └─StreamAgg	1.00	cop[tikv]		funcs:count(1)->Column#18
    └─TableFullScan	10000.00	cop[tikv]	table:access_path_selection	keep order:false, stats:pseudo