tables_test.go

// Copyright 2018 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// See the License for the specific language governing permissions and
// limitations under the License.

package infoschema_test

import (
	"fmt"
	"os"
	"strconv"
	"strings"

	. "github.com/pingcap/check"
	"github.com/pingcap/parser/auth"
	"github.com/pingcap/parser/mysql"
	"github.com/pingcap/tidb/domain"
	"github.com/pingcap/tidb/infoschema"
	"github.com/pingcap/tidb/kv"
	"github.com/pingcap/tidb/session"
	"github.com/pingcap/tidb/statistics"
	"github.com/pingcap/tidb/statistics/handle"
	"github.com/pingcap/tidb/store/mockstore"
	"github.com/pingcap/tidb/util"
	"github.com/pingcap/tidb/util/testkit"
	"github.com/pingcap/tidb/util/testleak"
	"github.com/pingcap/tidb/util/testutil"
)

var _ = Suite(&testTableSuite{})

type testTableSuite struct {
	store kv.Storage
	dom   *domain.Domain
}

func (s *testTableSuite) SetUpSuite(c *C) {
	testleak.BeforeTest()

	var err error
	s.store, err = mockstore.NewMockTikvStore()
	c.Assert(err, IsNil)
	session.DisableStats4Test()
	s.dom, err = session.BootstrapSession(s.store)
	c.Assert(err, IsNil)
}

func (s *testTableSuite) TearDownSuite(c *C) {
	defer testleak.AfterTest(c)()
	s.dom.Close()
	s.store.Close()
}

func (s *testTableSuite) TestInfoschemaFieldValue(c *C) {
	tk := testkit.NewTestKit(c, s.store)
	tk.MustExec("use test")
	tk.MustExec("drop table if exists numschema, timeschema")
	tk.MustExec("create table numschema(i int(2), f float(4,2), d decimal(4,3))")
	tk.MustExec("create table timeschema(d date, dt datetime(3), ts timestamp(3), t time(4), y year(4))")
	tk.MustExec("create table strschema(c char(3), c2 varchar(3), b blob(3), t text(3))")
	tk.MustExec("create table floatschema(a float, b double(7, 3))")

	tk.MustQuery("select CHARACTER_MAXIMUM_LENGTH,CHARACTER_OCTET_LENGTH,NUMERIC_PRECISION,NUMERIC_SCALE,DATETIME_PRECISION from information_schema.COLUMNS where table_name='numschema'").
		Check(testkit.Rows("<nil> <nil> 2 0 <nil>", "<nil> <nil> 4 2 <nil>", "<nil> <nil> 4 3 <nil>")) // FIXME: for mysql first one will be "<nil> <nil> 10 0 <nil>"
	tk.MustQuery("select CHARACTER_MAXIMUM_LENGTH,CHARACTER_OCTET_LENGTH,NUMERIC_PRECISION,NUMERIC_SCALE,DATETIME_PRECISION from information_schema.COLUMNS where table_name='timeschema'").
		Check(testkit.Rows("<nil> <nil> <nil> <nil> <nil>", "<nil> <nil> <nil> <nil> 3", "<nil> <nil> <nil> <nil> 3", "<nil> <nil> <nil> <nil> 4", "<nil> <nil> <nil> <nil> <nil>"))
	tk.MustQuery("select CHARACTER_MAXIMUM_LENGTH,CHARACTER_OCTET_LENGTH,NUMERIC_PRECISION,NUMERIC_SCALE,DATETIME_PRECISION from information_schema.COLUMNS where table_name='strschema'").
		Check(testkit.Rows("3 3 <nil> <nil> <nil>", "3 3 <nil> <nil> <nil>", "3 3 <nil> <nil> <nil>", "3 3 <nil> <nil> <nil>")) // FIXME: for mysql last two will be "255 255 <nil> <nil> <nil>", "255 255 <nil> <nil> <nil>"
	tk.MustQuery("select NUMERIC_SCALE from information_schema.COLUMNS where table_name='floatschema'").
		Check(testkit.Rows("<nil>", "3"))

	// Test for auto increment ID.
	tk.MustExec("drop table if exists t")
	tk.MustExec("create table t (c int auto_increment primary key, d int)")
	tk.MustQuery("select auto_increment from information_schema.tables where table_name='t'").Check(
		testkit.Rows("1"))
	tk.MustExec("insert into t(c, d) values(1, 1)")
	tk.MustQuery("select auto_increment from information_schema.tables where table_name='t'").Check(
		testkit.Rows("30002"))

	tk.MustExec("create user xxx")
	tk.MustExec("flush privileges")

	// Test for length of enum and set
	tk.MustExec("drop table if exists t")
	tk.MustExec("create table t ( s set('a','bc','def','ghij') default NULL, e1 enum('a', 'ab', 'cdef'), s2 SET('1','2','3','4','1585','ONE','TWO','Y','N','THREE'))")
	tk.MustQuery("select column_name, character_maximum_length from information_schema.columns where table_schema=Database() and table_name = 't' and column_name = 's'").Check(
		testkit.Rows("s 13"))
	tk.MustQuery("select column_name, character_maximum_length from information_schema.columns where table_schema=Database() and table_name = 't' and column_name = 's2'").Check(
		testkit.Rows("s2 30"))
	tk.MustQuery("select column_name, character_maximum_length from information_schema.columns where table_schema=Database() and table_name = 't' and column_name = 'e1'").Check(
		testkit.Rows("e1 4"))

	tk1 := testkit.NewTestKit(c, s.store)
	tk1.MustExec("use test")
	c.Assert(tk1.Se.Auth(&auth.UserIdentity{
		Username: "xxx",
		Hostname: "127.0.0.1",
	}, nil, nil), IsTrue)

	tk1.MustQuery("select distinct(table_schema) from information_schema.tables").Check(testkit.Rows("INFORMATION_SCHEMA"))

	// Fix issue 9836
	sm := &mockSessionManager{make(map[uint64]*util.ProcessInfo, 1)}
	sm.processInfoMap[1] = &util.ProcessInfo{
		ID:      1,
		User:    "root",
		Host:    "127.0.0.1",
		Command: mysql.ComQuery,
		StmtCtx: tk.Se.GetSessionVars().StmtCtx,
	}
	tk.Se.SetSessionManager(sm)
	tk.MustQuery("SELECT user,host,command FROM information_schema.processlist;").Check(testkit.Rows("root 127.0.0.1 Query"))
}

func (s *testTableSuite) TestDataForTableStatsField(c *C) {
	s.dom.SetStatsUpdating(true)
	oldExpiryTime := infoschema.TableStatsCacheExpiry
	infoschema.TableStatsCacheExpiry = 0
	defer func() { infoschema.TableStatsCacheExpiry = oldExpiryTime }()

	do := s.dom
	h := do.StatsHandle()
	h.Clear()
	is := do.InfoSchema()
	tk := testkit.NewTestKit(c, s.store)

	tk.MustExec("use test")
	tk.MustExec("drop table if exists t")
	tk.MustExec("create table t (c int, d int, e char(5), index idx(e))")
	h.HandleDDLEvent(<-h.DDLEventCh())
	tk.MustQuery("select table_rows, avg_row_length, data_length, index_length from information_schema.tables where table_name='t'").Check(
		testkit.Rows("0 0 0 0"))
	tk.MustExec(`insert into t(c, d, e) values(1, 2, "c"), (2, 3, "d"), (3, 4, "e")`)
	c.Assert(h.DumpStatsDeltaToKV(handle.DumpAll), IsNil)
	c.Assert(h.Update(is), IsNil)
	tk.MustQuery("select table_rows, avg_row_length, data_length, index_length from information_schema.tables where table_name='t'").Check(
		testkit.Rows("3 17 51 3"))
	tk.MustExec(`insert into t(c, d, e) values(4, 5, "f")`)
	c.Assert(h.DumpStatsDeltaToKV(handle.DumpAll), IsNil)
	c.Assert(h.Update(is), IsNil)
	tk.MustQuery("select table_rows, avg_row_length, data_length, index_length from information_schema.tables where table_name='t'").Check(
		testkit.Rows("4 17 68 4"))
	tk.MustExec("delete from t where c >= 3")
	c.Assert(h.DumpStatsDeltaToKV(handle.DumpAll), IsNil)
	c.Assert(h.Update(is), IsNil)
	tk.MustQuery("select table_rows, avg_row_length, data_length, index_length from information_schema.tables where table_name='t'").Check(
		testkit.Rows("2 17 34 2"))
	tk.MustExec("delete from t where c=3")
	c.Assert(h.DumpStatsDeltaToKV(handle.DumpAll), IsNil)
	c.Assert(h.Update(is), IsNil)
	tk.MustQuery("select table_rows, avg_row_length, data_length, index_length from information_schema.tables where table_name='t'").Check(
		testkit.Rows("2 17 34 2"))
}

func (s *testTableSuite) TestCharacterSetCollations(c *C) {
	tk := testkit.NewTestKit(c, s.store)

	// The description column is not important
	tk.MustQuery("SELECT default_collate_name, maxlen FROM information_schema.character_sets ORDER BY character_set_name").Check(
		testkit.Rows("ascii_bin 1", "binary 1", "latin1_bin 1", "utf8_bin 3", "utf8mb4_bin 4"))

	// The is_default column is not important
	// but the id's are used by client libraries and must be stable
	tk.MustQuery("SELECT character_set_name, id, sortlen FROM information_schema.collations ORDER BY collation_name").Check(
		testkit.Rows("ascii 65 1", "binary 63 1", "latin1 47 1", "utf8 83 1", "utf8mb4 46 1"))

	// Test charset/collation in information_schema.COLUMNS table.
	tk.MustExec("DROP DATABASE IF EXISTS charset_collate_test")
	tk.MustExec("CREATE DATABASE charset_collate_test; USE charset_collate_test")

	// TODO: Specifying the charset for national char/varchar should not be supported.
	tk.MustExec(`CREATE TABLE charset_collate_col_test(
		c_int int,
		c_float float,
		c_bit bit,
		c_bool bool,
		c_char char(1) charset ascii collate ascii_bin,
		c_nchar national char(1) charset ascii collate ascii_bin,
		c_binary binary,
		c_varchar varchar(1) charset ascii collate ascii_bin,
		c_nvarchar national varchar(1) charset ascii collate ascii_bin,
		c_varbinary varbinary(1),
		c_year year,
		c_date date,
		c_time time,
		c_datetime datetime,
		c_timestamp timestamp,
		c_blob blob,
		c_tinyblob tinyblob,
		c_mediumblob mediumblob,
		c_longblob longblob,
		c_text text charset ascii collate ascii_bin,
		c_tinytext tinytext charset ascii collate ascii_bin,
		c_mediumtext mediumtext charset ascii collate ascii_bin,
		c_longtext longtext charset ascii collate ascii_bin,
		c_json json,
		c_enum enum('1') charset ascii collate ascii_bin,
		c_set set('1') charset ascii collate ascii_bin
	)`)

	tk.MustQuery(`SELECT column_name, character_set_name, collation_name
					FROM information_schema.COLUMNS
					WHERE table_schema = "charset_collate_test" AND table_name = "charset_collate_col_test"
					ORDER BY column_name`,
	).Check(testkit.Rows(
		"c_binary <nil> <nil>",
		"c_bit <nil> <nil>",
		"c_blob <nil> <nil>",
		"c_bool <nil> <nil>",
		"c_char ascii ascii_bin",
		"c_date <nil> <nil>",
		"c_datetime <nil> <nil>",
		"c_enum ascii ascii_bin",
		"c_float <nil> <nil>",
		"c_int <nil> <nil>",
		"c_json <nil> <nil>",
		"c_longblob <nil> <nil>",
		"c_longtext ascii ascii_bin",
		"c_mediumblob <nil> <nil>",
		"c_mediumtext ascii ascii_bin",
		"c_nchar ascii ascii_bin",
		"c_nvarchar ascii ascii_bin",
		"c_set ascii ascii_bin",
		"c_text ascii ascii_bin",
		"c_time <nil> <nil>",
		"c_timestamp <nil> <nil>",
		"c_tinyblob <nil> <nil>",
		"c_tinytext ascii ascii_bin",
		"c_varbinary <nil> <nil>",
		"c_varchar ascii ascii_bin",
		"c_year <nil> <nil>",
	))
	tk.MustExec("DROP DATABASE charset_collate_test")
}

type mockSessionManager struct {
	processInfoMap map[uint64]*util.ProcessInfo
}

func (sm *mockSessionManager) ShowProcessList() map[uint64]*util.ProcessInfo { return sm.processInfoMap }

func (sm *mockSessionManager) GetProcessInfo(id uint64) (*util.ProcessInfo, bool) {
	rs, ok := sm.processInfoMap[id]
	return rs, ok
}

func (sm *mockSessionManager) Kill(connectionID uint64, query bool) {}

func (s *testTableSuite) TestSomeTables(c *C) {
	tk := testkit.NewTestKit(c, s.store)

	tk.MustQuery("select * from information_schema.COLLATION_CHARACTER_SET_APPLICABILITY where COLLATION_NAME='utf8mb4_bin';").Check(
		testkit.Rows("utf8mb4_bin utf8mb4"))
	tk.MustQuery("select * from information_schema.SESSION_VARIABLES where VARIABLE_NAME='tidb_retry_limit';").Check(testkit.Rows("tidb_retry_limit 10"))
	tk.MustQuery("select * from information_schema.ENGINES;").Check(testkit.Rows("InnoDB DEFAULT Supports transactions, row-level locking, and foreign keys YES YES YES"))
	tk.MustQuery("select * from information_schema.TABLE_CONSTRAINTS where TABLE_NAME='gc_delete_range';").Check(testkit.Rows("def mysql delete_range_index mysql gc_delete_range UNIQUE"))
	tk.MustQuery("select * from information_schema.KEY_COLUMN_USAGE where TABLE_NAME='stats_meta' and COLUMN_NAME='table_id';").Check(
		testkit.Rows("def mysql tbl def mysql stats_meta table_id 1 <nil> <nil> <nil> <nil>"))
	tk.MustQuery("select * from information_schema.STATISTICS where TABLE_NAME='columns_priv' and COLUMN_NAME='Host';").Check(
		testkit.Rows("def mysql columns_priv 0 mysql PRIMARY 1 Host A <nil> <nil> <nil>  BTREE  "))
	tk.MustQuery("select * from information_schema.USER_PRIVILEGES where PRIVILEGE_TYPE='Select';").Check(testkit.Rows("'root'@'%' def Select YES"))

	sm := &mockSessionManager{make(map[uint64]*util.ProcessInfo, 2)}
	sm.processInfoMap[1] = &util.ProcessInfo{
		ID:      1,
		User:    "user-1",
		Host:    "localhost",
		DB:      "information_schema",
		Command: byte(1),
		State:   1,
		Info:    "do something",
		StmtCtx: tk.Se.GetSessionVars().StmtCtx,
	}
	sm.processInfoMap[2] = &util.ProcessInfo{
		ID:      2,
		User:    "user-2",
		Host:    "localhost",
		DB:      "test",
		Command: byte(2),
		State:   2,
		Info:    strings.Repeat("x", 101),
		StmtCtx: tk.Se.GetSessionVars().StmtCtx,
	}
	tk.Se.SetSessionManager(sm)
	tk.MustQuery("select * from information_schema.PROCESSLIST order by ID;").Sort().Check(
		testkit.Rows(
			fmt.Sprintf("1 user-1 localhost information_schema Quit 9223372036 1 %s 0", "do something"),
			fmt.Sprintf("2 user-2 localhost test Init DB 9223372036 2 %s 0", strings.Repeat("x", 101)),
		))
	tk.MustQuery("SHOW PROCESSLIST;").Sort().Check(
		testkit.Rows(
			fmt.Sprintf("1 user-1 localhost information_schema Quit 9223372036 1 %s", "do something"),
			fmt.Sprintf("2 user-2 localhost test Init DB 9223372036 2 %s", strings.Repeat("x", 100)),
		))
	tk.MustQuery("SHOW FULL PROCESSLIST;").Sort().Check(
		testkit.Rows(
			fmt.Sprintf("1 user-1 localhost information_schema Quit 9223372036 1 %s", "do something"),
			fmt.Sprintf("2 user-2 localhost test Init DB 9223372036 2 %s", strings.Repeat("x", 101)),
		))

	sm = &mockSessionManager{make(map[uint64]*util.ProcessInfo, 2)}
	sm.processInfoMap[1] = &util.ProcessInfo{
		ID:      1,
		User:    "user-1",
		Host:    "localhost",
		DB:      "information_schema",
		Command: byte(1),
		State:   1,
		Info:    nil,
		StmtCtx: tk.Se.GetSessionVars().StmtCtx,
	}
	sm.processInfoMap[2] = &util.ProcessInfo{
		ID:      2,
		User:    "user-2",
		Host:    "localhost",
		DB:      nil,
		Command: byte(2),
		State:   2,
		Info:    strings.Repeat("x", 101),
		StmtCtx: tk.Se.GetSessionVars().StmtCtx,
	}
	tk.Se.SetSessionManager(sm)
	tk.MustQuery("select * from information_schema.PROCESSLIST order by ID;").Check(
		testkit.Rows(
			fmt.Sprintf("1 user-1 localhost information_schema Quit 9223372036 1 %s 0", "<nil>"),
			fmt.Sprintf("2 user-2 localhost <nil> Init DB 9223372036 2 %s 0", strings.Repeat("x", 101)),
		))
	tk.MustQuery("SHOW PROCESSLIST;").Sort().Check(
		testkit.Rows(
			fmt.Sprintf("1 user-1 localhost information_schema Quit 9223372036 1 %s", "<nil>"),
			fmt.Sprintf("2 user-2 localhost <nil> Init DB 9223372036 2 %s", strings.Repeat("x", 100)),
		))
	tk.MustQuery("SHOW FULL PROCESSLIST;").Sort().Check(
		testkit.Rows(
			fmt.Sprintf("1 user-1 localhost information_schema Quit 9223372036 1 %s", "<nil>"),
			fmt.Sprintf("2 user-2 localhost <nil> Init DB 9223372036 2 %s", strings.Repeat("x", 101)),
		))
	tk.MustQuery("select * from information_schema.PROCESSLIST where db is null;").Check(
		testkit.Rows(
			fmt.Sprintf("2 user-2 localhost <nil> Init DB 9223372036 2 %s 0", strings.Repeat("x", 101)),
		))
	tk.MustQuery("select * from information_schema.PROCESSLIST where Info is null;").Check(
		testkit.Rows(
			fmt.Sprintf("1 user-1 localhost information_schema Quit 9223372036 1 %s 0", "<nil>"),
		))
}

func (s *testTableSuite) TestSchemataCharacterSet(c *C) {
	tk := testkit.NewTestKit(c, s.store)
	tk.MustExec("CREATE DATABASE `foo` DEFAULT CHARACTER SET = 'utf8mb4'")
	tk.MustQuery("select default_character_set_name, default_collation_name FROM information_schema.SCHEMATA  WHERE schema_name = 'foo'").Check(
		testkit.Rows("utf8mb4 utf8mb4_bin"))
	tk.MustExec("drop database `foo`")
}

func (s *testTableSuite) TestProfiling(c *C) {
	tk := testkit.NewTestKit(c, s.store)
	tk.MustQuery("select * from information_schema.profiling").Check(testkit.Rows())
	tk.MustExec("set @@profiling=1")
	tk.MustQuery("select * from information_schema.profiling").Check(testkit.Rows("0 0  0 0 0 0 0 0 0 0 0 0 0 0   0"))
}

func (s *testTableSuite) TestViews(c *C) {
	tk := testkit.NewTestKit(c, s.store)
	tk.MustExec("CREATE DEFINER='root'@'localhost' VIEW test.v1 AS SELECT 1")
	tk.MustQuery("SELECT * FROM information_schema.views WHERE table_schema='test' AND table_name='v1'").Check(testkit.Rows("def test v1 SELECT 1 CASCADED NO root@localhost DEFINER utf8mb4 utf8mb4_bin"))
	tk.MustQuery("SELECT table_catalog, table_schema, table_name, table_type, engine, version, row_format, table_rows, avg_row_length, data_length, max_data_length, index_length, data_free, auto_increment, update_time, check_time, table_collation, checksum, create_options, table_comment FROM information_schema.tables WHERE table_schema='test' AND table_name='v1'").Check(testkit.Rows("def test v1 VIEW <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> <nil> VIEW"))
}

func (s *testTableSuite) TestTableIDAndIndexID(c *C) {
	tk := testkit.NewTestKit(c, s.store)
	tk.MustExec("drop table if exists test.t")
	tk.MustExec("create table test.t (a int, b int, primary key(a), key k1(b))")
	tblID, err := strconv.Atoi(tk.MustQuery("select tidb_table_id from information_schema.tables where table_schema = 'test' and table_name = 't'").Rows()[0][0].(string))
	c.Assert(err, IsNil)
	c.Assert(tblID, Greater, 0)
	tk.MustQuery("select * from information_schema.tidb_indexes where table_schema = 'test' and table_name = 't'").Check(testkit.Rows("test t 0 PRIMARY 1 a <nil>  0", "test t 1 k1 1 b <nil>  1"))
}

func (s *testTableSuite) TestSlowQuery(c *C) {
	tk := testkit.NewTestKit(c, s.store)
	// Prepare slow log file.
	slowLogFileName := "tidb_slow.log"
	f, err := os.OpenFile(slowLogFileName, os.O_CREATE|os.O_WRONLY, 0644)
	c.Assert(err, IsNil)
	defer os.Remove(slowLogFileName)
	_, err = f.Write([]byte(`# Time: 2019-02-12T19:33:56.571953+08:00
# Txn_start_ts: 406315658548871171
# User: root@127.0.0.1
# Conn_ID: 6
# Query_time: 4.895492
# Process_time: 0.161 Request_count: 1 Total_keys: 100001 Process_keys: 100000
# Wait_time: 0.101
# Backoff_time: 0.092
# DB: test
# Is_internal: false
# Digest: 42a1c8aae6f133e934d4bf0147491709a8812ea05ff8819ec522780fe657b772
# Stats: t1:1,t2:2
# Cop_proc_avg: 0.1 Cop_proc_p90: 0.2 Cop_proc_max: 0.03 Cop_proc_addr: 127.0.0.1:20160
# Cop_wait_avg: 0.05 Cop_wait_p90: 0.6 Cop_wait_max: 0.8 Cop_wait_addr: 0.0.0.0:20160
# Mem_max: 70724
select * from t_slim;`))
	c.Assert(f.Close(), IsNil)
	c.Assert(err, IsNil)

	tk.MustExec(fmt.Sprintf("set @@tidb_slow_query_file='%v'", slowLogFileName))
	tk.MustExec("set time_zone = '+08:00';")
	re := tk.MustQuery("select * from information_schema.slow_query")
	re.Check(testutil.RowsWithSep("|",
		"2019-02-12 19:33:56.571953|406315658548871171|root|127.0.0.1|6|4.895492|0.161|0.101|0.092|1|100001|100000|test||0|42a1c8aae6f133e934d4bf0147491709a8812ea05ff8819ec522780fe657b772|t1:1,t2:2|0.1|0.2|0.03|127.0.0.1:20160|0.05|0.6|0.8|0.0.0.0:20160|70724|select * from t_slim;"))
	tk.MustExec("set time_zone = '+00:00';")
	re = tk.MustQuery("select * from information_schema.slow_query")
	re.Check(testutil.RowsWithSep("|", "2019-02-12 11:33:56.571953|406315658548871171|root|127.0.0.1|6|4.895492|0.161|0.101|0.092|1|100001|100000|test||0|42a1c8aae6f133e934d4bf0147491709a8812ea05ff8819ec522780fe657b772|t1:1,t2:2|0.1|0.2|0.03|127.0.0.1:20160|0.05|0.6|0.8|0.0.0.0:20160|70724|select * from t_slim;"))
}

func (s *testTableSuite) TestForAnalyzeStatus(c *C) {
	tk := testkit.NewTestKit(c, s.store)
	statistics.ClearHistoryJobs()
	tk.MustExec("use test")
	tk.MustExec("drop table if exists t")
	tk.MustExec("create table t (a int, b int, index idx(a))")
	tk.MustExec("insert into t values (1,2),(3,4)")
	tk.MustExec("analyze table t")

	result := tk.MustQuery("select * from information_schema.analyze_status").Sort()

	c.Assert(len(result.Rows()), Equals, 2)
	c.Assert(result.Rows()[0][0], Equals, "test")
	c.Assert(result.Rows()[0][1], Equals, "t")
	c.Assert(result.Rows()[0][2], Equals, "")
	c.Assert(result.Rows()[0][3], Equals, "analyze columns")
	c.Assert(result.Rows()[0][4], Equals, "2")
	c.Assert(result.Rows()[0][5], NotNil)
	c.Assert(result.Rows()[0][6], Equals, "finished")

	c.Assert(len(result.Rows()), Equals, 2)
	c.Assert(result.Rows()[1][0], Equals, "test")
	c.Assert(result.Rows()[1][1], Equals, "t")
	c.Assert(result.Rows()[1][2], Equals, "")
	c.Assert(result.Rows()[1][3], Equals, "analyze index idx")
	c.Assert(result.Rows()[1][4], Equals, "2")
	c.Assert(result.Rows()[1][5], NotNil)
	c.Assert(result.Rows()[1][6], Equals, "finished")
}

func (s *testTableSuite) TestColumnStatistics(c *C) {
	tk := testkit.NewTestKit(c, s.store)
	tk.MustQuery("select * from information_schema.column_statistics").Check(testkit.Rows())
}