all_test.go

// Copyright 2014 The ql Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package ql

import (
	"bytes"
	"crypto/md5"
	"database/sql"
	"fmt"
	"io"
	"io/ioutil"
	"log"
	"math/big"
	"math/rand"
	"os"
	"path"
	"path/filepath"
	"runtime"
	"runtime/debug"
	"strconv"
	"strings"
	"sync"
	"testing"
	"time"

	"github.com/cznic/strutil"
)

// Note: All benchmarks report MB/s equal to record/s.
const benchScale = 1e6

func init() {
	log.SetFlags(log.Flags() | log.Lshortfile)
	isTesting = true
	use(dieHard, caller, dumpTables2, dumpTables3, dumpFields, dumpFlds, dumpCols, typeof, stypeof)
}

func dieHard(exitValue int) {
	debug.PrintStack()
	os.Exit(exitValue)
}

func dbg(s string, va ...interface{}) {
	if s == "" {
		s = strings.Repeat("%v ", len(va))
	}
	_, fn, fl, _ := runtime.Caller(1)
	fmt.Printf("dbg %s:%d: ", path.Base(fn), fl)
	fmt.Printf(s, va...)
	fmt.Println()
}

func caller(s string, va ...interface{}) {
	if s == "" {
		s = strings.Repeat("%v ", len(va))
	}
	_, fn, fl, _ := runtime.Caller(2)
	fmt.Printf("caller: %s:%d: ", path.Base(fn), fl)
	fmt.Printf(s, va...)
	fmt.Println()
	_, fn, fl, _ = runtime.Caller(1)
	fmt.Printf("\tcallee: %s:%d: ", path.Base(fn), fl)
	fmt.Println()
}

func use(...interface{}) {}

func dumpTables3(r *root) {
	fmt.Printf("---- r.head %d, r.thead %p\n", r.head, r.thead)
	for k, v := range r.tables {
		fmt.Printf("%p: %s->%+v\n", v, k, v)
	}
	fmt.Println("<exit>")
}

func dumpTables2(s storage) {
	fmt.Println("****")
	h := int64(1)
	for h != 0 {
		d, err := s.Read(nil, h)
		if err != nil {
			log.Fatal(err)
		}

		fmt.Printf("%d: %v\n", h, d)
		h = d[0].(int64)
	}
	fmt.Println("<exit>")
}

func (db *DB) dumpTables() string {
	var buf bytes.Buffer
	for k, v := range db.root.tables {
		buf.WriteString(fmt.Sprintf("%s->%v, %v\n", k, v.h, v.next))
	}
	return buf.String()
}

func fldsString(f []*fld) string {
	a := []string{}
	for _, v := range f {
		a = append(a, v.name)
	}
	return strings.Join(a, " ")
}

type testDB interface {
	setup() (db *DB, err error)
	mark() (err error)
	teardown(ctx *TCtx) (err error)
}

var (
	_ testDB = (*fileTestDB)(nil)
	_ testDB = (*memTestDB)(nil)
)

type memTestDB struct {
	db *DB
	m0 int64
}

func (m *memTestDB) setup() (db *DB, err error) {
	if m.db, err = OpenMem(); err != nil {
		return
	}

	return m.db, nil
}

func (m *memTestDB) mark() (err error) {
	m.m0, err = m.db.store.Verify()
	if err != nil {
		m.m0 = -1
	}
	return
}

func (m *memTestDB) teardown(ctx *TCtx) (err error) {
	if m.m0 < 0 {
		return
	}

	n, err := m.db.store.Verify()
	if err != nil {
		return
	}

	if g, e := n, m.m0; g != e {
		return fmt.Errorf("STORAGE LEAK: allocs: got %d, exp %d", g, e)
	}

	if ctx == nil {
		return nil
	}

	_, _, err = m.db.Execute(ctx, txCommit)
	return err
}

type fileTestDB struct {
	db   *DB
	gmp0 int
	m0   int64
}

func (m *fileTestDB) setup() (db *DB, err error) {
	m.gmp0 = runtime.GOMAXPROCS(0)
	f, err := ioutil.TempFile("", "ql-test-")
	if err != nil {
		return
	}

	if m.db, err = OpenFile(f.Name(), &Options{}); err != nil {
		return
	}

	return m.db, nil
}

func (m *fileTestDB) mark() (err error) {
	m.m0, err = m.db.store.Verify()
	if err != nil {
		m.m0 = -1
	}
	return
}

func (m *fileTestDB) teardown(ctx *TCtx) (err error) {
	runtime.GOMAXPROCS(m.gmp0)
	defer func() {
		f := m.db.store.(*file)
		errSet(&err, m.db.Close())
		os.Remove(f.f0.Name())
		if f.wal != nil {
			os.Remove(f.wal.Name())
		}
	}()

	if m.m0 < 0 {
		return
	}

	n, err := m.db.store.Verify()
	if err != nil {
		return
	}

	if g, e := n, m.m0; g != e {
		return fmt.Errorf("STORAGE LEAK: allocs: got %d, exp %d", g, e)
	}

	if ctx == nil {
		return nil
	}

	_, _, err = m.db.Execute(ctx, txCommit)
	return err
}

type osFileTestDB struct {
	db   *DB
	gmp0 int
	m0   int64
}

func (m *osFileTestDB) setup() (db *DB, err error) {
	m.gmp0 = runtime.GOMAXPROCS(0)
	f, err := ioutil.TempFile("", "ql-test-osfile")
	if err != nil {
		return
	}

	if m.db, err = OpenFile("", &Options{OSFile: f}); err != nil {
		return
	}

	return m.db, nil
}

func (m *osFileTestDB) mark() (err error) {
	m.m0, err = m.db.store.Verify()
	if err != nil {
		m.m0 = -1
	}
	return
}

func (m *osFileTestDB) teardown(ctx *TCtx) (err error) {
	runtime.GOMAXPROCS(m.gmp0)
	defer func() {
		f := m.db.store.(*file)
		errSet(&err, m.db.Close())
		os.Remove(f.f0.Name())
		if f.wal != nil {
			os.Remove(f.wal.Name())
		}
	}()

	if m.m0 < 0 {
		return
	}

	n, err := m.db.store.Verify()
	if err != nil {
		return
	}

	if g, e := n, m.m0; g != e {
		return fmt.Errorf("STORAGE LEAK: allocs: got %d, exp %d", g, e)
	}

	if ctx == nil {
		return nil
	}

	_, _, err = m.db.Execute(ctx, txCommit)
	return err
}

func TestMemStorage(t *testing.T) {
	test(t, &memTestDB{})
}

func TestFileStorage(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping test in short mode.")
	}

	test(t, &fileTestDB{})
}

func TestOSFileStorage(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping test in short mode.")
	}

	test(t, &osFileTestDB{})
}

var (
	compiledCommit        = MustCompile("COMMIT;")
	compiledCreate        = MustCompile("BEGIN TRANSACTION; CREATE TABLE t (i16 int16, s16 string, s string);")
	compiledCreate2       = MustCompile("BEGIN TRANSACTION; CREATE TABLE t (i16 int16, s16 string, s string); COMMIT;")
	compiledIns           = MustCompile("INSERT INTO t VALUES($1, $2, $3);")
	compiledSelect        = MustCompile("SELECT * FROM t;")
	compiledSelectOrderBy = MustCompile("SELECT * FROM t ORDER BY i16, s16;")
	compiledTrunc         = MustCompile("BEGIN TRANSACTION; TRUNCATE TABLE t; COMMIT;")
)

func rnds16(rng *rand.Rand, n int) string {
	a := make([]string, n)
	for i := range a {
		a[i] = fmt.Sprintf("%016x", rng.Int63())
	}
	return strings.Join(a, "")
}

var (
	benchmarkScaleOnce  sync.Once
	benchmarkSelectOnce = map[string]bool{}
)

func benchProlog(b *testing.B) {
	benchmarkScaleOnce.Do(func() {
		b.Logf(`
=============================================================
NOTE: All benchmarks report records/s as %d bytes/s.
=============================================================`, int64(benchScale))
	})
}

func benchmarkSelect(b *testing.B, n int, sel List, ts testDB) {
	if testing.Verbose() {
		benchProlog(b)
		id := fmt.Sprintf("%T|%d", ts, n)
		if !benchmarkSelectOnce[id] {
			b.Logf(`Having a table of %d records, each of size 1kB, measure the performance of
%s
`, n, sel)
		}
		benchmarkSelectOnce[id] = true
	}

	db, err := ts.setup()
	if err != nil {
		b.Error(err)
		return
	}

	defer ts.teardown(nil)

	ctx := NewRWCtx()
	if _, i, err := db.Execute(ctx, compiledCreate); err != nil {
		b.Error(i, err)
		return
	}

	rng := rand.New(rand.NewSource(42))
	for i := 0; i < n; i++ {
		if _, _, err := db.Execute(ctx, compiledIns, int16(rng.Int()), rnds16(rng, 1), rnds16(rng, 63)); err != nil {
			b.Error(err)
			return
		}
	}

	if _, i, err := db.Execute(ctx, compiledCommit); err != nil {
		b.Error(i, err)
		return
	}

	b.SetBytes(int64(n) * benchScale)
	runtime.GC()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		rs, index, err := db.Execute(nil, sel)
		if err != nil {
			b.Error(index, err)
			return
		}

		if err = rs[0].Do(false, func(record []interface{}) (bool, error) { return true, nil }); err != nil {
			b.Errorf("%v %T(%#v)", err, err, err)
			return
		}
	}
	b.StopTimer()

}

func BenchmarkSelectMem1kBx1e2(b *testing.B) {
	benchmarkSelect(b, 1e2, compiledSelect, &memTestDB{})
}

func BenchmarkSelectMem1kBx1e3(b *testing.B) {
	benchmarkSelect(b, 1e3, compiledSelect, &memTestDB{})
}

func BenchmarkSelectMem1kBx1e4(b *testing.B) {
	benchmarkSelect(b, 1e4, compiledSelect, &memTestDB{})
}

func BenchmarkSelectMem1kBx1e5(b *testing.B) {
	benchmarkSelect(b, 1e5, compiledSelect, &memTestDB{})
}

func BenchmarkSelectFile1kBx1e2(b *testing.B) {
	benchmarkSelect(b, 1e2, compiledSelect, &fileTestDB{})
}

func BenchmarkSelectFile1kBx1e3(b *testing.B) {
	benchmarkSelect(b, 1e3, compiledSelect, &fileTestDB{})
}

func BenchmarkSelectFile1kBx1e4(b *testing.B) {
	benchmarkSelect(b, 1e4, compiledSelect, &fileTestDB{})
}

func BenchmarkSelectFile1kBx1e5(b *testing.B) {
	benchmarkSelect(b, 1e5, compiledSelect, &fileTestDB{})
}

func BenchmarkSelectOrderedMem1kBx1e2(b *testing.B) {
	benchmarkSelect(b, 1e2, compiledSelectOrderBy, &memTestDB{})
}

func BenchmarkSelectOrderedMem1kBx1e3(b *testing.B) {
	benchmarkSelect(b, 1e3, compiledSelectOrderBy, &memTestDB{})
}

func BenchmarkSelectOrderedMem1kBx1e4(b *testing.B) {
	benchmarkSelect(b, 1e4, compiledSelectOrderBy, &memTestDB{})
}

func BenchmarkSelectOrderedFile1kBx1e2(b *testing.B) {
	benchmarkSelect(b, 1e2, compiledSelectOrderBy, &fileTestDB{})
}

func BenchmarkSelectOrderedFile1kBx1e3(b *testing.B) {
	benchmarkSelect(b, 1e3, compiledSelectOrderBy, &fileTestDB{})
}

func BenchmarkSelectOrderedFile1kBx1e4(b *testing.B) {
	benchmarkSelect(b, 1e4, compiledSelectOrderBy, &fileTestDB{})
}

func TestString(t *testing.T) {
	for _, v := range testdata {
		a := strings.Split(v, "\n|")
		v = a[0]
		v = strings.Replace(v, "&or;", "|", -1)
		v = strings.Replace(v, "&oror;", "||", -1)
		l, err := Compile(v)
		if err != nil {
			continue
		}

		if s := l.String(); len(s) == 0 {
			t.Fatal("List.String() returned empty string")
		}
	}
}

var benchmarkInsertOnce = map[string]bool{}

func benchmarkInsert(b *testing.B, batch, total int, ts testDB) {
	if testing.Verbose() {
		benchProlog(b)
		id := fmt.Sprintf("%T|%d|%d", ts, batch, total)
		if !benchmarkInsertOnce[id] {
			b.Logf(`In batches of %d record(s), insert a total of %d records, each of size 1kB, into a table.

`, batch, total)
		}
		benchmarkInsertOnce[id] = true
	}

	if total%batch != 0 {
		b.Fatal("internal error 001")
	}

	db, err := ts.setup()
	if err != nil {
		b.Error(err)
		return
	}

	defer ts.teardown(nil)

	ctx := NewRWCtx()
	if _, i, err := db.Execute(ctx, compiledCreate2); err != nil {
		b.Error(i, err)
		return
	}

	s := fmt.Sprintf(`(0, "0123456789abcdef", "%s"),`, rnds16(rand.New(rand.NewSource(42)), 63))
	var buf bytes.Buffer
	buf.WriteString("BEGIN TRANSACTION; INSERT INTO t VALUES\n")
	for i := 0; i < batch; i++ {
		buf.WriteString(s)
	}
	buf.WriteString("; COMMIT;")
	ins, err := Compile(buf.String())
	if err != nil {
		b.Error(err)
		return
	}

	b.SetBytes(int64(total) * benchScale)
	runtime.GC()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		for n := 0; n != total; n += batch {
			if _, _, err = db.Execute(ctx, ins); err != nil {
				b.Error(err)
				return
			}
		}
		b.StopTimer()
		if _, _, err = db.Execute(ctx, compiledTrunc); err != nil {
			b.Error(err)
		}
		b.StartTimer()
	}
	b.StopTimer()
}

func BenchmarkInsertMem1kBn1e0t1e2(b *testing.B) {
	benchmarkInsert(b, 1e0, 1e2, &memTestDB{})
}

func BenchmarkInsertFile1kBn1e0t1e2(b *testing.B) {
	benchmarkInsert(b, 1e0, 1e2, &fileTestDB{})
}

//=============================================================================

func BenchmarkInsertMem1kBn1e1t1e2(b *testing.B) {
	benchmarkInsert(b, 1e1, 1e2, &memTestDB{})
}

func BenchmarkInsertFile1kBn1e1t1e2(b *testing.B) {
	benchmarkInsert(b, 1e1, 1e2, &fileTestDB{})
}

func BenchmarkInsertMem1kBn1e1t1e3(b *testing.B) {
	benchmarkInsert(b, 1e1, 1e3, &memTestDB{})
}

func BenchmarkInsertFile1kBn1e1t1e3(b *testing.B) {
	benchmarkInsert(b, 1e1, 1e3, &fileTestDB{})
}

//=============================================================================

func BenchmarkInsertMem1kBn1e2t1e2(b *testing.B) {
	benchmarkInsert(b, 1e2, 1e2, &memTestDB{})
}

func BenchmarkInsertFile1kBn1e2t1e2(b *testing.B) {
	benchmarkInsert(b, 1e2, 1e2, &fileTestDB{})
}

func BenchmarkInsertMem1kBn1e2t1e3(b *testing.B) {
	benchmarkInsert(b, 1e2, 1e3, &memTestDB{})
}

func BenchmarkInsertFile1kBn1e2t1e3(b *testing.B) {
	benchmarkInsert(b, 1e2, 1e3, &fileTestDB{})
}

func BenchmarkInsertMem1kBn1e2t1e4(b *testing.B) {
	benchmarkInsert(b, 1e2, 1e4, &memTestDB{})
}

func BenchmarkInsertFile1kBn1e2t1e4(b *testing.B) {
	benchmarkInsert(b, 1e2, 1e4, &fileTestDB{})
}

//=============================================================================

func BenchmarkInsertMem1kBn1e3t1e3(b *testing.B) {
	benchmarkInsert(b, 1e3, 1e3, &memTestDB{})
}

func BenchmarkInsertFile1kBn1e3t1e3(b *testing.B) {
	benchmarkInsert(b, 1e3, 1e3, &fileTestDB{})
}

func BenchmarkInsertMem1kBn1e3t1e4(b *testing.B) {
	benchmarkInsert(b, 1e3, 1e4, &memTestDB{})
}

func BenchmarkInsertFile1kBn1e3t1e4(b *testing.B) {
	benchmarkInsert(b, 1e3, 1e4, &fileTestDB{})
}

func BenchmarkInsertMem1kBn1e3t1e5(b *testing.B) {
	benchmarkInsert(b, 1e3, 1e5, &memTestDB{})
}

func BenchmarkInsertFile1kBn1e3t1e5(b *testing.B) {
	benchmarkInsert(b, 1e3, 1e5, &fileTestDB{})
}

func TestReopen(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping test in short mode.")
	}

	f, err := ioutil.TempFile("", "ql-test-")
	if err != nil {
		t.Fatal(err)
	}

	nm := f.Name()
	if err = f.Close(); err != nil {
		t.Fatal(err)
	}

	defer func() {
		if nm != "" {
			os.Remove(nm)
		}
	}()

	db, err := OpenFile(nm, &Options{})
	if err != nil {
		t.Error(err)
		return
	}

	for _, tn := range "abc" {
		ql := fmt.Sprintf(`
BEGIN TRANSACTION;
	CREATE TABLE %c (i int, s string);
	INSERT INTO %c VALUES (%d, "<%c>");
COMMIT;
		`, tn, tn, tn-'a'+42, tn)
		_, i, err := db.Run(NewRWCtx(), ql)
		if err != nil {
			db.Close()
			t.Error(i, err)
			return
		}
	}

	if err = db.Close(); err != nil {
		t.Error(err)
		return
	}

	db, err = OpenFile(nm, &Options{})
	if err != nil {
		t.Error(err)
		return
	}

	defer func() {
		if err = db.Close(); err != nil {
			t.Error(err)
		}
	}()

	if _, _, err = db.Run(NewRWCtx(), "BEGIN TRANSACTION; DROP TABLE b; COMMIT;"); err != nil {
		t.Error(err)
		return
	}

	for _, tn := range "ac" {
		ql := fmt.Sprintf("SELECT * FROM %c;", tn)
		rs, i, err := db.Run(NewRWCtx(), ql)
		if err != nil {
			t.Error(i, err)
			return
		}

		if rs == nil {
			t.Error(rs)
			return
		}

		rid := 0
		if err = rs[0].Do(false, func(r []interface{}) (bool, error) {
			rid++
			if rid != 1 {
				return false, fmt.Errorf("rid %d", rid)
			}

			if g, e := recStr(r), fmt.Sprintf(`%d, "<%c>"`, tn-'a'+42, tn); g != e {
				return false, fmt.Errorf("g `%s`, e `%s`", g, e)
			}

			return true, nil
		}); err != nil {
			t.Error(err)
			return
		}
	}
}

func recStr(data []interface{}) string {
	a := make([]string, len(data))
	for i, v := range data {
		switch x := v.(type) {
		case string:
			a[i] = fmt.Sprintf("%q", x)
		default:
			a[i] = fmt.Sprint(x)
		}
	}
	return strings.Join(a, ", ")
}

//TODO +test long blob types with multiple inner chunks.

func TestLastInsertID(t *testing.T) {
	table := []struct {
		ql string
		id int
	}{
		// 0
		{`BEGIN TRANSACTION; CREATE TABLE t (c int); COMMIT`, 0},
		{`BEGIN TRANSACTION; INSERT INTO t VALUES (41); COMMIT`, 1},
		{`BEGIN TRANSACTION; INSERT INTO t VALUES (42);`, 2},
		{`INSERT INTO t VALUES (43)`, 3},
		{`ROLLBACK; BEGIN TRANSACTION; INSERT INTO t VALUES (44); COMMIT`, 4},

		//5
		{`BEGIN TRANSACTION; INSERT INTO t VALUES (45); COMMIT`, 5},
		{`
		BEGIN TRANSACTION;
			INSERT INTO t VALUES (46); // 6
			BEGIN TRANSACTION;
				INSERT INTO t VALUES (47); // 7
				INSERT INTO t VALUES (48); // 8
			ROLLBACK;
			INSERT INTO t VALUES (49); // 9
		COMMIT`, 9},
		{`
		BEGIN TRANSACTION;
			INSERT INTO t VALUES (50); // 10
			BEGIN TRANSACTION;
				INSERT INTO t VALUES (51); // 11
				INSERT INTO t VALUES (52); // 12
			ROLLBACK;
		COMMIT;`, 10},
		{`BEGIN TRANSACTION; INSERT INTO t VALUES (53); ROLLBACK`, 10},
		{`BEGIN TRANSACTION; INSERT INTO t VALUES (54); COMMIT`, 14},
		// 10
		{`BEGIN TRANSACTION; CREATE TABLE u (c int); COMMIT`, 14},
		{`
		BEGIN TRANSACTION;
			INSERT INTO t SELECT * FROM u;
		COMMIT;`, 14},
		{`BEGIN TRANSACTION; INSERT INTO u VALUES (150); COMMIT`, 15},
		{`
		BEGIN TRANSACTION;
			INSERT INTO t SELECT * FROM u;
		COMMIT;`, 16},
	}

	db, err := OpenMem()
	if err != nil {
		t.Fatal(err)
	}

	ctx := NewRWCtx()
	for i, test := range table {
		l, err := Compile(test.ql)
		if err != nil {
			t.Fatal(i, err)
		}

		if _, _, err = db.Execute(ctx, l); err != nil {
			t.Fatal(i, err)
		}

		if g, e := ctx.LastInsertID, int64(test.id); g != e {
			t.Fatal(i, g, e)
		}
	}
}

func ExampleTCtx_lastInsertID() {
	ins := MustCompile("BEGIN TRANSACTION; INSERT INTO t VALUES ($1); COMMIT;")

	db, err := OpenMem()
	if err != nil {
		panic(err)
	}

	ctx := NewRWCtx()
	if _, _, err = db.Run(ctx, `
		BEGIN TRANSACTION;
			CREATE TABLE t (c int);
			INSERT INTO t VALUES (1), (2), (3);
		COMMIT;
	`); err != nil {
		panic(err)
	}

	if _, _, err = db.Execute(ctx, ins, int64(42)); err != nil {
		panic(err)
	}

	id := ctx.LastInsertID
	rs, _, err := db.Run(ctx, `SELECT * FROM t WHERE id() == $1`, id)
	if err != nil {
		panic(err)
	}

	if err = rs[0].Do(false, func(data []interface{}) (more bool, err error) {
		fmt.Println(data)
		return true, nil
	}); err != nil {
		panic(err)
	}
	// Output:
	// [42]
}

func Example_recordsetFields() {
	// See RecordSet.Fields documentation

	db, err := OpenMem()
	if err != nil {
		panic(err)
	}

	rs, _, err := db.Run(NewRWCtx(), `
		BEGIN TRANSACTION;
			CREATE TABLE t (s string, i int);
			CREATE TABLE u (s string, i int);
			INSERT INTO t VALUES
				("a", 1),
				("a", 2),
				("b", 3),
				("b", 4),
			;
			INSERT INTO u VALUES
				("A", 10),
				("A", 20),
				("B", 30),
				("B", 40),
			;
		COMMIT;
		
		SELECT t.s+u.s as a, t.i+u.i as b, "noName", "name" as Named FROM t, u;
		
		SELECT DISTINCT s as S, sum(i) as I FROM (
			SELECT t.s+u.s as s, t.i+u.i, 3 as i FROM t, u;
		)
		GROUP BY s
		ORDER BY I;
		
		SELECT DISTINCT * FROM (
			SELECT t.s+u.s as S, t.i+u.i, 3 as I FROM t, u;
		)
		WHERE I < $1
		ORDER BY S;
		`, 42)
	if err != nil {
		panic(err)
	}

	for i, v := range rs {
		fields, err := v.Fields()
		switch {
		case err != nil:
			fmt.Printf("Fields[%d]: error: %s\n", i, err)
		default:
			fmt.Printf("Fields[%d]: %#v\n", i, fields)
		}
	}
	// Output:
	// Fields[0]: []string{"a", "b", "", "Named"}
	// Fields[1]: []string{"S", "I"}
	// Fields[2]: []string{"S", "", "I"}
}

func TestRowsAffected(t *testing.T) {
	db, err := OpenMem()
	if err != nil {
		t.Fatal(err)
	}

	ctx := NewRWCtx()
	ctx.LastInsertID, ctx.RowsAffected = -1, -1
	if _, _, err = db.Run(ctx, `
	BEGIN TRANSACTION;
		CREATE TABLE t (i int);
	COMMIT;
	`); err != nil {
		t.Fatal(err)
	}

	if g, e := ctx.LastInsertID, int64(0); g != e {
		t.Fatal(g, e)
	}

	if g, e := ctx.RowsAffected, int64(0); g != e {
		t.Fatal(g, e)
	}

	if _, _, err = db.Run(ctx, `
	BEGIN TRANSACTION;
		INSERT INTO t VALUES (1), (2), (3);
	COMMIT;
	`); err != nil {
		t.Fatal(err)
	}

	if g, e := ctx.LastInsertID, int64(3); g != e {
		t.Fatal(g, e)
	}

	if g, e := ctx.RowsAffected, int64(3); g != e {
		t.Fatal(g, e)
	}

	if _, _, err = db.Run(ctx, `
	BEGIN TRANSACTION;
		INSERT INTO t
		SELECT * FROM t WHERE i == 2;
	COMMIT;
	`); err != nil {
		t.Fatal(err)
	}

	if g, e := ctx.LastInsertID, int64(4); g != e {
		t.Fatal(g, e)
	}

	if g, e := ctx.RowsAffected, int64(1); g != e {
		t.Fatal(g, e)
	}

	if _, _, err = db.Run(ctx, `
	BEGIN TRANSACTION;
		DELETE FROM t WHERE i == 2;
	COMMIT;
	`); err != nil {
		t.Fatal(err)
	}

	if g, e := ctx.LastInsertID, int64(4); g != e {
		t.Fatal(g, e)
	}

	if g, e := ctx.RowsAffected, int64(2); g != e {
		t.Fatal(g, e)
	}

	if _, _, err = db.Run(ctx, `
	BEGIN TRANSACTION;
		UPDATE t i = 42 WHERE i == 3;
	COMMIT;
	`); err != nil {
		t.Fatal(err)
	}

	if g, e := ctx.LastInsertID, int64(4); g != e {
		t.Fatal(g, e)
	}

	if g, e := ctx.RowsAffected, int64(1); g != e {
		t.Fatal(g, e)
	}
}

func dumpDB(db *DB, tag string) (string, error) {
	var buf bytes.Buffer
	f := strutil.IndentFormatter(&buf, "\t")
	f.Format("---- %s%i\n", tag)
	for nm, tab := range db.root.tables {
		hh := tab.hhead
		h := tab.head
		f.Format("%u%q: hhead %d, head %d, scols0 %q, scols %q%i\n", nm, hh, h, cols2meta(tab.cols0), cols2meta(tab.cols))
		for h != 0 {
			rec, err := db.store.Read(nil, h, tab.cols...)
			if err != nil {
				return "", err
			}

			f.Format("record @%d: %v\n", h, rec)
			h = rec[0].(int64)
		}
		f.Format("%u")
		for i, v := range tab.indices {
			if v == nil {
				continue
			}

			xname := v.name
			cname := "id()"
			if i != 0 {
				cname = tab.cols0[i-1].name
			}
			f.Format("index %s on %s%i\n", xname, cname)
			it, _, err := v.x.Seek([]interface{}{nil})
			if err != nil {
				return "", err
			}

			for {
				k, v, err := it.Next()
				if err != nil {
					if err == io.EOF {
						break
					}

					return "", err
				}

				f.Format("%v: %v\n", k, v)
			}
			f.Format("%u")
		}
	}

	return buf.String(), nil
}

func testIndices(db *DB, t *testing.T) {
	ctx := NewRWCtx()
	var err error
	e := func(q string) {
		s0, err := dumpDB(db, "pre\n\t"+q)
		if err != nil {
			t.Log(s0)
			t.Fatal(err)
		}

		if _, _, err = db.Run(ctx, q); err != nil {
			t.Log(q)
			t.Fatal(err)
		}

		s, err := dumpDB(db, "post\n\t"+q)
		if err != nil {
			t.Log(s0)
			t.Log(s)
			t.Fatal(err)
		}

		if db.isMem {
			return
		}

		nm := db.Name()

		if err = db.Close(); err != nil {
			t.Log(s0)
			t.Log(s)
			t.Fatal(err)
		}

		if db, err = OpenFile(nm, &Options{}); err != nil {
			t.Log(s0)
			t.Log(s)
			t.Fatal(err)
		}

		if s, err = dumpDB(db, "reopened"); err != nil {
			t.Log(s0)
			t.Log(s)
			t.Fatal(err)
		}

	}

	e(`	BEGIN TRANSACTION;
			CREATE TABLE t (i int);
		COMMIT;`)
	e(`	BEGIN TRANSACTION;
			CREATE TABLE IF NOT EXISTS Index2 (TableName string);
			CREATE INDEX x ON t (id());
		COMMIT;`)
	e(`	BEGIN TRANSACTION;
			INSERT INTO t VALUES(42);
		COMMIT;`)
	e(`	BEGIN TRANSACTION;
			INSERT INTO t VALUES(24);
		COMMIT;`)
	e(`	BEGIN TRANSACTION;
			CREATE INDEX xi ON t (i);
		COMMIT;`)
	e(`	BEGIN TRANSACTION;
			INSERT INTO t VALUES(1);
		COMMIT;`)
	e(`	BEGIN TRANSACTION;
			INSERT INTO t VALUES(999);
		COMMIT;`)
	e(`	BEGIN TRANSACTION;
			UPDATE t i = 240 WHERE i == 24;
		COMMIT;`)
	e(`	BEGIN TRANSACTION;
			DELETE FROM t WHERE i == 240;
		COMMIT;`)
	e(`	BEGIN TRANSACTION;
			TRUNCATE TABLE t;
		COMMIT;`)
	e(`	BEGIN TRANSACTION;
			DROP TABLE IF EXISTS t;
			CREATE TABLE t (i int, s string);
			CREATE INDEX xi ON t (i);
			INSERT INTO t VALUES (42, "foo");
		COMMIT;`)
	e(`	BEGIN TRANSACTION;
			ALTER TABLE t DROP COLUMN i;
		COMMIT;`)

	e(`	BEGIN TRANSACTION;
			DROP TABLE IF EXISTS t;
			CREATE TABLE t (i int);
			CREATE INDEX x ON t (i);
			INSERT INTO t VALUES (42);
			INSERT INTO t SELECT 10*i FROM t;
		COMMIT;`)
	e(`	BEGIN TRANSACTION;
			DROP TABLE IF EXISTS t;
			CREATE TABLE t (i int);
			CREATE INDEX x ON t (i);
			INSERT INTO t VALUES (42);
		COMMIT;
		BEGIN TRANSACTION;
			INSERT INTO t SELECT 10*i FROM t;
		COMMIT;`)
	e(`	BEGIN TRANSACTION;
			DROP TABLE IF EXISTS t;
			CREATE TABLE t (i int);
			CREATE INDEX x ON t (i);
			INSERT INTO t VALUES (42);
			DROP INDEX x;
		COMMIT;`)
	e(`	BEGIN TRANSACTION;
			DROP TABLE IF EXISTS t;
			CREATE TABLE t (i int);
			CREATE INDEX x ON t (i);
			INSERT INTO t VALUES (42);
		COMMIT;
		BEGIN TRANSACTION;
			DROP INDEX x;
		COMMIT;`)
	e(`	BEGIN TRANSACTION;
			DROP TABLE IF EXISTS t;
			CREATE TABLE t (i int);
			CREATE INDEX x ON t (i);
			INSERT INTO t VALUES (42);
		COMMIT;`)
	e(`
		BEGIN TRANSACTION;
			DROP INDEX x;
		COMMIT;`)
	e(`	BEGIN TRANSACTION;
			DROP TABLE IF EXISTS t;
			CREATE TABLE t (i int);
			CREATE INDEX x ON t (i);
			ALTER TABLE t ADD s string;
		COMMIT;`)
	e(`	BEGIN TRANSACTION;
			DROP TABLE IF EXISTS t;
			CREATE TABLE t (i int);
			CREATE INDEX x ON t (i);
		COMMIT;`)
	e(`	BEGIN TRANSACTION;
			ALTER TABLE t ADD s string;
		COMMIT;`)
	e(`	BEGIN TRANSACTION;
			DROP TABLE IF EXISTS t;
			CREATE TABLE t (i bigint);
			CREATE INDEX x ON t (i);
			INSERT INTO t VALUES(42);
		COMMIT;`)
	e(`	BEGIN TRANSACTION;
			DROP TABLE IF EXISTS t;
			CREATE TABLE t (i int);
			CREATE INDEX x ON t (i+1, 2*i); // Non simple index.
		COMMIT;`)
	e(`	BEGIN TRANSACTION;
			DROP INDEX x;
		COMMIT;`)

	if err = db.Close(); err != nil {
		t.Fatal(err)
	}
}

func TestIndices(t *testing.T) {
	db, err := OpenMem()
	if err != nil {
		t.Fatal(err)
	}

	testIndices(db, t)
	if testing.Short() {
		t.Skip("skipping test in short mode.")
	}

	dir, err := ioutil.TempDir("", "ql-test")

	if err != nil {
		t.Fatal(err)
	}

	defer func() {
		os.RemoveAll(dir)

	}()

	nm := filepath.Join(dir, "ql.db")
	db, err = OpenFile(nm, &Options{CanCreate: true})
	if err != nil {
		t.Fatal(err)
	}

	testIndices(db, t)
}

var benchmarkInsertBoolOnce = map[string]bool{}

func benchmarkInsertBool(b *testing.B, db *DB, size int, selectivity float64, index bool, teardown func()) {
	if testing.Verbose() {
		benchProlog(b)
		id := fmt.Sprintf("%t|%d|%g|%t", db.isMem, size, selectivity, index)
		if !benchmarkInsertBoolOnce[id] {
			s := "INDEXED"
			if !index {
				s = "NON " + s
			}
			b.Logf(`Insert %d records into a table having a single bool %s column. Batch size: 1 record.

`, size, s)
		}
		benchmarkInsertBoolOnce[id] = true
	}

	if teardown != nil {
		defer teardown()
	}

	ctx := NewRWCtx()
	if _, _, err := db.Run(ctx, `
		BEGIN TRANSACTION;
			CREATE TABLE t (b bool);
	`); err != nil {
		b.Fatal(err)
	}

	if index {
		if _, _, err := db.Run(ctx, `
			CREATE INDEX x ON t (b);
		`); err != nil {
			b.Fatal(err)
		}
	}

	ins, err := Compile("INSERT INTO t VALUES($1);")
	if err != nil {
		b.Fatal(err)
	}

	trunc, err := Compile("TRUNCATE TABLE t;")
	if err != nil {
		b.Fatal(err)
	}

	begin, err := Compile("BEGIN TRANSACTION;")
	if err != nil {
		b.Fatal(err)
	}

	commit, err := Compile("COMMIT;")
	if err != nil {
		b.Fatal(err)
	}

	rng := rand.New(rand.NewSource(42))
	debug.FreeOSMemory()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		b.StopTimer()
		if i != 0 {
			if _, _, err = db.Execute(ctx, begin); err != nil {
				b.Fatal(err)
			}
		}

		if _, _, err = db.Execute(ctx, trunc); err != nil {
			b.Fatal(err)
		}

		b.StartTimer()
		for j := 0; j < size; j++ {
			if _, _, err = db.Execute(ctx, ins, rng.Float64() < selectivity); err != nil {
				b.Fatal(err)
			}
		}
		if _, _, err = db.Execute(ctx, commit); err != nil {
			b.Fatal(err)
		}
	}
	b.StopTimer()
	b.SetBytes(int64(size) * benchScale)
}

func benchmarkInsertBoolMem(b *testing.B, size int, sel float64, index bool) {
	db, err := OpenMem()
	if err != nil {
		b.Fatal(err)
	}

	benchmarkInsertBool(b, db, size, sel, index, nil)
}

func BenchmarkInsertBoolMemNoX1e1(b *testing.B) {
	benchmarkInsertBoolMem(b, 1e1, 0.5, false)
}

func BenchmarkInsertBoolMemX1e1(b *testing.B) {
	benchmarkInsertBoolMem(b, 1e1, 0.5, true)
}

func BenchmarkInsertBoolMemNoX1e2(b *testing.B) {
	benchmarkInsertBoolMem(b, 1e2, 0.5, false)
}

func BenchmarkInsertBoolMemX1e2(b *testing.B) {
	benchmarkInsertBoolMem(b, 1e2, 0.5, true)
}

func BenchmarkInsertBoolMemNoX1e3(b *testing.B) {
	benchmarkInsertBoolMem(b, 1e3, 0.5, false)
}

func BenchmarkInsertBoolMemX1e3(b *testing.B) {
	benchmarkInsertBoolMem(b, 1e3, 0.5, true)
}

func BenchmarkInsertBoolMemNoX1e4(b *testing.B) {
	benchmarkInsertBoolMem(b, 1e4, 0.5, false)
}

func BenchmarkInsertBoolMemX1e4(b *testing.B) {
	benchmarkInsertBoolMem(b, 1e4, 0.5, true)
}

func BenchmarkInsertBoolMemNoX1e5(b *testing.B) {
	benchmarkInsertBoolMem(b, 1e5, 0.5, false)
}

func BenchmarkInsertBoolMemX1e5(b *testing.B) {
	benchmarkInsertBoolMem(b, 1e5, 0.5, true)
}

func benchmarkInsertBoolFile(b *testing.B, size int, sel float64, index bool) {
	dir, err := ioutil.TempDir("", "ql-bench-")
	if err != nil {
		b.Fatal(err)
	}

	n := runtime.GOMAXPROCS(0)
	db, err := OpenFile(filepath.Join(dir, "ql.db"), &Options{CanCreate: true})
	if err != nil {
		b.Fatal(err)
	}

	benchmarkInsertBool(b, db, size, sel, index, func() {
		runtime.GOMAXPROCS(n)
		db.Close()
		os.RemoveAll(dir)
	})
}

func BenchmarkInsertBoolFileNoX1e1(b *testing.B) {
	benchmarkInsertBoolFile(b, 1e1, 0.5, false)
}

func BenchmarkInsertBoolFileX1e1(b *testing.B) {
	benchmarkInsertBoolFile(b, 1e1, 0.5, true)
}

func BenchmarkInsertBoolFileNoX1e2(b *testing.B) {
	benchmarkInsertBoolFile(b, 1e2, 0.5, false)
}

func BenchmarkInsertBoolFileX1e2(b *testing.B) {
	benchmarkInsertBoolFile(b, 1e2, 0.5, true)
}

func BenchmarkInsertBoolFileNoX1e3(b *testing.B) {
	benchmarkInsertBoolFile(b, 1e3, 0.5, false)
}

func BenchmarkInsertBoolFileX1e3(b *testing.B) {
	benchmarkInsertBoolFile(b, 1e3, 0.5, true)
}

var benchmarkSelectBoolOnce = map[string]bool{}

func benchmarkSelectBool(b *testing.B, db *DB, size int, selectivity float64, index bool, teardown func()) {
	sel, err := Compile("SELECT * FROM t WHERE b;")
	if err != nil {
		b.Fatal(err)
	}

	if testing.Verbose() {
		benchProlog(b)
		id := fmt.Sprintf("%t|%d|%g|%t", db.isMem, size, selectivity, index)
		if !benchmarkSelectBoolOnce[id] {
			s := "INDEXED"
			if !index {
				s = "NON " + s
			}
			b.Logf(`A table has a single %s bool column b. Insert %d records with a random bool value,
%.0f%% of them are true. Measure the performance of
%s
`, s, size, 100*selectivity, sel)
		}
		benchmarkSelectBoolOnce[id] = true
	}

	if teardown != nil {
		defer teardown()
	}

	ctx := NewRWCtx()
	if _, _, err := db.Run(ctx, `
		BEGIN TRANSACTION;
			CREATE TABLE t (b bool);
	`); err != nil {
		b.Fatal(err)
	}

	if index {
		if _, _, err := db.Run(ctx, `
			CREATE INDEX x ON t (b);
		`); err != nil {
			b.Fatal(err)
		}
	}

	ins, err := Compile("INSERT INTO t VALUES($1);")
	if err != nil {
		b.Fatal(err)
	}

	var n int64
	rng := rand.New(rand.NewSource(42))
	for j := 0; j < size; j++ {
		v := rng.Float64() < selectivity
		if v {
			n++
		}
		if _, _, err = db.Execute(ctx, ins, v); err != nil {
			b.Fatal(err)
		}
	}

	if _, _, err := db.Run(ctx, "COMMIT;"); err != nil {
		b.Fatal(err)
	}

	debug.FreeOSMemory()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		var m int64
		rss, _, err := db.Execute(nil, sel)
		if err != nil {
			b.Fatal(err)
		}

		if err = rss[0].Do(false, func([]interface{}) (bool, error) {
			m++
			return true, nil
		}); err != nil {
			b.Fatal(err)
		}
		if g, e := n, m; g != e {
			b.Fatal(g, e)
		}
	}
	b.StopTimer()
	b.SetBytes(n * benchScale)
}

func benchmarkSelectBoolMem(b *testing.B, size int, sel float64, index bool) {
	db, err := OpenMem()
	if err != nil {
		b.Fatal(err)
	}

	benchmarkSelectBool(b, db, size, sel, index, nil)
}

// ----

func BenchmarkSelectBoolMemNoX1e1Perc50(b *testing.B) {
	benchmarkSelectBoolMem(b, 1e1, 0.5, false)
}

func BenchmarkSelectBoolMemX1e1Perc50(b *testing.B) {
	benchmarkSelectBoolMem(b, 1e1, 0.5, true)
}

func BenchmarkSelectBoolMemNoX1e2Perc50(b *testing.B) {
	benchmarkSelectBoolMem(b, 1e2, 0.5, false)
}

func BenchmarkSelectBoolMemX1e2Perc50(b *testing.B) {
	benchmarkSelectBoolMem(b, 1e2, 0.5, true)
}

func BenchmarkSelectBoolMemNoX1e3Perc50(b *testing.B) {
	benchmarkSelectBoolMem(b, 1e3, 0.5, false)
}

func BenchmarkSelectBoolMemX1e3Perc50(b *testing.B) {
	benchmarkSelectBoolMem(b, 1e3, 0.5, true)
}

func BenchmarkSelectBoolMemNoX1e4Perc50(b *testing.B) {
	benchmarkSelectBoolMem(b, 1e4, 0.5, false)
}

func BenchmarkSelectBoolMemX1e4Perc50(b *testing.B) {
	benchmarkSelectBoolMem(b, 1e4, 0.5, true)
}

func BenchmarkSelectBoolMemNoX1e5Perc50(b *testing.B) {
	benchmarkSelectBoolMem(b, 1e5, 0.5, false)
}

func BenchmarkSelectBoolMemX1e5Perc50(b *testing.B) {
	benchmarkSelectBoolMem(b, 1e5, 0.5, true)
}

// ----

func BenchmarkSelectBoolMemNoX1e1Perc5(b *testing.B) {
	benchmarkSelectBoolMem(b, 1e1, 0.05, false)
}

func BenchmarkSelectBoolMemX1e1Perc5(b *testing.B) {
	benchmarkSelectBoolMem(b, 1e1, 0.05, true)
}

func BenchmarkSelectBoolMemNoX1e2Perc5(b *testing.B) {
	benchmarkSelectBoolMem(b, 1e2, 0.05, false)
}

func BenchmarkSelectBoolMemX1e2Perc5(b *testing.B) {
	benchmarkSelectBoolMem(b, 1e2, 0.05, true)
}

func BenchmarkSelectBoolMemNoX1e3Perc5(b *testing.B) {
	benchmarkSelectBoolMem(b, 1e3, 0.05, false)
}

func BenchmarkSelectBoolMemX1e3Perc5(b *testing.B) {
	benchmarkSelectBoolMem(b, 1e3, 0.05, true)
}

func BenchmarkSelectBoolMemNoX1e4Perc5(b *testing.B) {
	benchmarkSelectBoolMem(b, 1e4, 0.05, false)
}

func BenchmarkSelectBoolMemX1e4Perc5(b *testing.B) {
	benchmarkSelectBoolMem(b, 1e4, 0.05, true)
}

func BenchmarkSelectBoolMemNoX1e5Perc5(b *testing.B) {
	benchmarkSelectBoolMem(b, 1e5, 0.05, false)
}

func BenchmarkSelectBoolMemX1e5Perc5(b *testing.B) {
	benchmarkSelectBoolMem(b, 1e5, 0.05, true)
}

func benchmarkSelectBoolFile(b *testing.B, size int, sel float64, index bool) {
	dir, err := ioutil.TempDir("", "ql-bench-")
	if err != nil {
		b.Fatal(err)
	}

	n := runtime.GOMAXPROCS(0)
	db, err := OpenFile(filepath.Join(dir, "ql.db"), &Options{CanCreate: true})
	if err != nil {
		b.Fatal(err)
	}

	benchmarkSelectBool(b, db, size, sel, index, func() {
		runtime.GOMAXPROCS(n)
		db.Close()
		os.RemoveAll(dir)
	})
}

// ----

func BenchmarkSelectBoolFileNoX1e1Perc50(b *testing.B) {
	benchmarkSelectBoolFile(b, 1e1, 0.5, false)
}

func BenchmarkSelectBoolFileX1e1Perc50(b *testing.B) {
	benchmarkSelectBoolFile(b, 1e1, 0.5, true)
}

func BenchmarkSelectBoolFileNoX1e2Perc50(b *testing.B) {
	benchmarkSelectBoolFile(b, 1e2, 0.5, false)
}

func BenchmarkSelectBoolFileX1e2Perc50(b *testing.B) {
	benchmarkSelectBoolFile(b, 1e2, 0.5, true)
}

func BenchmarkSelectBoolFileNoX1e3Perc50(b *testing.B) {
	benchmarkSelectBoolFile(b, 1e3, 0.5, false)
}

func BenchmarkSelectBoolFileX1e3Perc50(b *testing.B) {
	benchmarkSelectBoolFile(b, 1e3, 0.5, true)
}

func BenchmarkSelectBoolFileNoX1e4Perc50(b *testing.B) {
	benchmarkSelectBoolFile(b, 1e4, 0.5, false)
}

func BenchmarkSelectBoolFileX1e4Perc50(b *testing.B) {
	benchmarkSelectBoolFile(b, 1e4, 0.5, true)
}

// ----

func BenchmarkSelectBoolFileNoX1e1Perc5(b *testing.B) {
	benchmarkSelectBoolFile(b, 1e1, 0.05, false)
}

func BenchmarkSelectBoolFileX1e1Perc5(b *testing.B) {
	benchmarkSelectBoolFile(b, 1e1, 0.05, true)
}

func BenchmarkSelectBoolFileNoX1e2Perc5(b *testing.B) {
	benchmarkSelectBoolFile(b, 1e2, 0.05, false)
}

func BenchmarkSelectBoolFileX1e2Perc5(b *testing.B) {
	benchmarkSelectBoolFile(b, 1e2, 0.05, true)
}

func BenchmarkSelectBoolFileNoX1e3Perc5(b *testing.B) {
	benchmarkSelectBoolFile(b, 1e3, 0.05, false)
}

func BenchmarkSelectBoolFileX1e3Perc5(b *testing.B) {
	benchmarkSelectBoolFile(b, 1e3, 0.05, true)
}

func BenchmarkSelectBoolFileNoX1e4Perc5(b *testing.B) {
	benchmarkSelectBoolFile(b, 1e4, 0.05, false)
}

func BenchmarkSelectBoolFileX1e4Perc5(b *testing.B) {
	benchmarkSelectBoolFile(b, 1e4, 0.05, true)
}

func TestIndex(t *testing.T) {
	db, err := OpenMem()
	if err != nil {
		t.Fatal(err)
	}

	ctx := NewRWCtx()
	if _, _, err := db.Run(ctx, `
		BEGIN TRANSACTION;
			CREATE TABLE t (b bool);
	`); err != nil {
		t.Fatal(err)
	}

	if _, _, err := db.Run(ctx, `
			CREATE INDEX x ON t (b);
		`); err != nil {
		t.Fatal(err)
	}

	ins, err := Compile("INSERT INTO t VALUES($1);")
	if err != nil {
		t.Fatal(err)
	}

	size, selectivity := int(1e1), 0.5
	rng := rand.New(rand.NewSource(42))
	var n int64
	for j := 0; j < size; j++ {
		v := rng.Float64() < selectivity
		if v {
			n++
			t.Logf("id %d <- true", j+1)
		}
		if _, _, err = db.Execute(ctx, ins, v); err != nil {
			t.Fatal(err)
		}
	}

	if _, _, err := db.Run(ctx, "COMMIT;"); err != nil {
		t.Fatal(err)
	}

	s, err := dumpDB(db, "")
	if err != nil {
		t.Fatal(err)
	}

	t.Logf("n: %d\n%s", n, s)
	sel, err := Compile("SELECT id(), b FROM t WHERE b;")
	if err != nil {
		t.Fatal(err)
	}

	var m int64
	rss, _, err := db.Execute(nil, sel)
	if err != nil {
		t.Fatal(err)
	}

	if err = rss[0].Do(false, func(rec []interface{}) (bool, error) {
		t.Logf("%v", rec)
		m++
		return true, nil
	}); err != nil {
		t.Fatal(err)
	}

	if g, e := n, m; g != e {
		t.Fatal(g, e)
	}
}

var benchmarkCrossJoinOnce = map[string]bool{}

func benchmarkCrossJoin(b *testing.B, db *DB, create, sel List, size1, size2 int, index bool, teardown func()) {
	if testing.Verbose() {
		benchProlog(b)
		id := fmt.Sprintf("%t|%d|%d|%t", db.isMem, size1, size2, index)
		if !benchmarkCrossJoinOnce[id] {
			s := "INDEXED "
			if !index {
				s = "NON " + s
			}
			b.Logf(`Fill two %stables with %d and %d records of random numbers [0, 1). Measure the performance of
%s
`, s, size1, size2, sel)
		}
		benchmarkCrossJoinOnce[id] = true
	}

	if teardown != nil {
		defer teardown()
	}

	ctx := NewRWCtx()
	if _, _, err := db.Execute(ctx, create); err != nil {
		b.Fatal(err)
	}

	if index {
		if _, _, err := db.Execute(ctx, xjoinX); err != nil {
			b.Fatal(err)
		}
	}

	rng := rand.New(rand.NewSource(42))
	for i := 0; i < size1; i++ {
		if _, _, err := db.Execute(ctx, xjoinT, rng.Float64()); err != nil {
			b.Fatal(err)
		}
	}
	for i := 0; i < size2; i++ {
		if _, _, err := db.Execute(ctx, xjoinU, rng.Float64()); err != nil {
			b.Fatal(err)
		}
	}

	if _, _, err := db.Run(ctx, "COMMIT"); err != nil {
		b.Fatal(err)
	}

	rs, _, err := db.Execute(nil, sel)
	if err != nil {
		b.Fatal(err)
	}

	var n int
	debug.FreeOSMemory()
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		n = 0
		if err := rs[0].Do(false, func(rec []interface{}) (bool, error) {
			n++
			return true, nil
		}); err != nil {
			b.Fatal(err)
		}
	}
	b.StopTimer()
	b.SetBytes(int64(n) * benchScale)
}

var (
	xjoinCreate = MustCompile(`BEGIN TRANSACTION;
	CREATE TABLE t (f float);
	CREATE TABLE u (f float);`)
	xjoinSel = MustCompile(`SELECT *  FROM (SELECT f FROM t WHERE f < 0.1), (SELECT f FROM u where f < 0.1);`)
	xjoinT   = MustCompile("INSERT INTO t VALUES($1);")
	xjoinU   = MustCompile("INSERT INTO u VALUES($1);")
	xjoinX   = MustCompile(`CREATE INDEX x ON t (f); CREATE INDEX y ON u (f);`)
)

func benchmarkCrossJoinMem(b *testing.B, size1, size2 int, index bool) {
	db, err := OpenMem()
	if err != nil {
		b.Fatal(err)
	}

	benchmarkCrossJoin(b, db, xjoinCreate, xjoinSel, size1, size2, index, nil)
}

func benchmarkCrossJoinFile(b *testing.B, size1, size2 int, index bool) {
	dir, err := ioutil.TempDir("", "ql-bench-")
	if err != nil {
		b.Fatal(err)
	}

	n := runtime.GOMAXPROCS(0)
	db, err := OpenFile(filepath.Join(dir, "ql.db"), &Options{CanCreate: true})
	if err != nil {
		b.Fatal(err)
	}

	benchmarkCrossJoin(b, db, xjoinCreate, xjoinSel, size1, size2, index, func() {
		runtime.GOMAXPROCS(n)
		db.Close()
		os.RemoveAll(dir)
	})
}

func BenchmarkCrossJoinMem1e1NoX1e2(b *testing.B) {
	benchmarkCrossJoinMem(b, 1e1, 1e2, false)
}

func BenchmarkCrossJoinMem1e1X1e2(b *testing.B) {
	benchmarkCrossJoinMem(b, 1e1, 1e2, true)
}

func BenchmarkCrossJoinMem1e2NoX1e3(b *testing.B) {
	benchmarkCrossJoinMem(b, 1e2, 1e3, false)
}

func BenchmarkCrossJoinMem1e2X1e3(b *testing.B) {
	benchmarkCrossJoinMem(b, 1e2, 1e3, true)
}

func BenchmarkCrossJoinMem1e3NoX1e4(b *testing.B) {
	benchmarkCrossJoinMem(b, 1e3, 1e4, false)
}

func BenchmarkCrossJoinMem1e3X1e4(b *testing.B) {
	benchmarkCrossJoinMem(b, 1e3, 1e4, true)
}

func BenchmarkCrossJoinMem1e2NoX1e1(b *testing.B) {
	benchmarkCrossJoinMem(b, 1e2, 1e1, false)
}

func BenchmarkCrossJoinMem1e2X1e1(b *testing.B) {
	benchmarkCrossJoinMem(b, 1e2, 1e1, true)
}

func BenchmarkCrossJoinMem1e3NoX1e2(b *testing.B) {
	benchmarkCrossJoinMem(b, 1e3, 1e2, false)
}

func BenchmarkCrossJoinMem1e3X1e2(b *testing.B) {
	benchmarkCrossJoinMem(b, 1e3, 1e2, true)
}

func BenchmarkCrossJoinMem1e4NoX1e3(b *testing.B) {
	benchmarkCrossJoinMem(b, 1e4, 1e3, false)
}

func BenchmarkCrossJoinMem1e4X1e3(b *testing.B) {
	benchmarkCrossJoinMem(b, 1e4, 1e3, true)
}

// ----

func BenchmarkCrossJoinFile1e1NoX1e2(b *testing.B) {
	benchmarkCrossJoinFile(b, 1e1, 1e2, false)
}

func BenchmarkCrossJoinFile1e1X1e2(b *testing.B) {
	benchmarkCrossJoinFile(b, 1e1, 1e2, true)
}

func BenchmarkCrossJoinFile1e2NoX1e3(b *testing.B) {
	benchmarkCrossJoinFile(b, 1e2, 1e3, false)
}

func BenchmarkCrossJoinFile1e2X1e3(b *testing.B) {
	benchmarkCrossJoinFile(b, 1e2, 1e3, true)
}

func BenchmarkCrossJoinFile1e3NoX1e4(b *testing.B) {
	benchmarkCrossJoinFile(b, 1e3, 1e4, false)
}

func BenchmarkCrossJoinFile1e3X1e4(b *testing.B) {
	benchmarkCrossJoinFile(b, 1e3, 1e4, true)
}

func BenchmarkCrossJoinFile1e2NoX1e1(b *testing.B) {
	benchmarkCrossJoinFile(b, 1e2, 1e1, false)
}

func BenchmarkCrossJoinFile1e2X1e1(b *testing.B) {
	benchmarkCrossJoinFile(b, 1e2, 1e1, true)
}

func BenchmarkCrossJoinFile1e3NoX1e2(b *testing.B) {
	benchmarkCrossJoinFile(b, 1e3, 1e2, false)
}

func BenchmarkCrossJoinFile1e3X1e2(b *testing.B) {
	benchmarkCrossJoinFile(b, 1e3, 1e2, true)
}

func BenchmarkCrossJoinFile1e4NoX1e3(b *testing.B) {
	benchmarkCrossJoinFile(b, 1e4, 1e3, false)
}

func BenchmarkCrossJoinFile1e4X1e3(b *testing.B) {
	benchmarkCrossJoinFile(b, 1e4, 1e3, true)
}

func TestIssue35(t *testing.T) {
	var bigInt big.Int
	var bigRat big.Rat
	bigInt.SetInt64(42)
	bigRat.SetInt64(24)
	db, err := OpenMem()
	if err != nil {
		t.Fatal(err)
	}

	ctx := NewRWCtx()
	_, _, err = db.Run(ctx, `
	BEGIN TRANSACTION;
		CREATE TABLE t (i bigint, r bigrat);
		INSERT INTO t VALUES ($1, $2);
	COMMIT;
	`, bigInt, bigRat)
	if err != nil {
		t.Fatal(err)
	}

	bigInt.SetInt64(420)
	bigRat.SetInt64(240)

	rs, _, err := db.Run(nil, "SELECT * FROM t;")
	if err != nil {
		t.Fatal(err)
	}

	n := 0
	if err := rs[0].Do(false, func(rec []interface{}) (bool, error) {
		switch n {
		case 0:
			n++
			if g, e := fmt.Sprint(rec), "[42 24/1]"; g != e {
				t.Fatal(g, e)
			}

			return true, nil
		default:
			t.Fatal(n)
			panic("unreachable")
		}
	}); err != nil {
		t.Fatal(err)
	}
}

func TestIssue28(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping test in short mode.")
	}

	RegisterDriver()
	dir, err := ioutil.TempDir("", "ql-test-")
	if err != nil {
		t.Fatal(err)
	}

	defer os.RemoveAll(dir)
	pth := filepath.Join(dir, "ql.db")
	sdb, err := sql.Open("ql", "file://"+pth)
	if err != nil {
		t.Fatal(err)
	}

	defer sdb.Close()
	tx, err := sdb.Begin()
	if err != nil {
		t.Fatal(err)
	}

	if _, err = tx.Exec("CREATE TABLE t (i int);"); err != nil {
		t.Fatal(err)
	}

	if err = tx.Commit(); err != nil {
		t.Fatal(err)
	}

	if _, err = os.Stat(pth); err != nil {
		t.Fatal(err)
	}

	pth = filepath.Join(dir, "mem.db")
	mdb, err := sql.Open("ql", "memory://"+pth)
	if err != nil {
		t.Fatal(err)
	}

	defer mdb.Close()
	if tx, err = mdb.Begin(); err != nil {
		t.Fatal(err)
	}

	if _, err = tx.Exec("CREATE TABLE t (i int);"); err != nil {
		t.Fatal(err)
	}

	if err = tx.Commit(); err != nil {
		t.Fatal(err)
	}

	if _, err = os.Stat(pth); err == nil {
		t.Fatal(err)
	}
}

func dumpFields(f []*fld) string {
	a := []string{}
	for _, v := range f {
		a = append(a, fmt.Sprintf("%p: %q", v, v.name))
	}
	return strings.Join(a, ", ")
}

func TestIssue50(t *testing.T) { // https://github.com/cznic/ql/issues/50
	if testing.Short() {
		t.Skip("skipping test in short mode.")
	}

	const dbFileName = "scans.qldb"

	type Scan struct {
		ID        int
		Jobname   string
		Timestamp time.Time
		Data      []byte

		X, Y, Z            float64
		Alpha, Beta, Gamma float64
	}

	// querys
	const dbCreateTables = `
CREATE TABLE IF NOT EXISTS Scans (
	X float,
	Y float,
	Z float,
	Alpha float,
	Beta float,
	Gamma float,
	Timestamp time,
	Jobname string,
	Data blob
);
CREATE INDEX IF NOT EXISTS ScansId on Scans (id());
`

	const dbInsertScan = `
INSERT INTO Scans (Timestamp,Jobname,X,Y,Z,Alpha,Beta,Gamma,Data) VALUES(
$1,
$2,
$3,$4,$5,
$6,$7,$8,
$9
);
`

	const dbSelectOverview = `SELECT id() as ID, Jobname, Timestamp, Data, Y,Z, Gamma From Scans;`

	dir, err := ioutil.TempDir("", "ql-test-")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(dir)

	// create db
	t.Log("Opening db.")
	RegisterDriver()
	db, err := sql.Open("ql", filepath.Join(dir, dbFileName))
	if err != nil {
		t.Fatal(err)
	}
	defer db.Close()

	tx, err := db.Begin()
	if err != nil {
		return
	}
	_, err = tx.Exec(dbCreateTables)
	if err != nil {
		t.Fatal("could not create Table.", err)
	}

	err = tx.Commit()
	if err != nil {
		t.Fatal("could not commit transaction.", err)
	}

	// insert some data
	tx, err = db.Begin()
	if err != nil {
		t.Fatalf("db.Begin() Error - %v", err)
	}

	stmt, err := tx.Prepare(dbInsertScan)
	if err != nil {
		t.Fatalf("tx.Prepare(dbInsertScan) Error - %v", err)
	}
	defer stmt.Close()

	scanFnames := []string{"1.xyz", "2.xyz", "3.xyz"}
	for _, fname := range scanFnames {
		scanData, err := ioutil.ReadFile(filepath.Join("_testdata", fname))
		if err != nil {
			t.Fatalf("ioutil.ReadFile(%s) Error - %v", fname, err)
		}

		// hash before insert
		h := md5.New()
		h.Write(scanData)

		t.Logf("md5 of %s: %x", fname, h.Sum(nil))

		_, err = stmt.Exec(time.Now(), "Job-0815", 1.0, 2.0, 3.0, 0.1, 0.2, 0.3, scanData)
		if err != nil {
			t.Fatalf("stmt.Exec() Error - %v", err)
			return
		}
	}

	err = tx.Commit()
	if err != nil {
		t.Fatalf("tx.Commit() Error - %v", err)
	}

	// select the inserted data
	rows, err := db.Query(dbSelectOverview)
	if err != nil {
		t.Fatalf("db.Query(dbSelectOverview) Error - %v", err)
	}
	defer rows.Close()

	var scans []Scan
	for rows.Next() {
		var s Scan
		var data []byte

		err = rows.Scan(&s.ID, &s.Jobname, &s.Timestamp, &data, &s.Y, &s.Z, &s.Gamma)
		if err != nil {
			t.Fatalf("rows.Scan(&s..) Error - %v", err)
		}
		scans = append(scans, s)

		// hash after select
		h := md5.New()
		h.Write(data)

		t.Logf("md5 of %d: %x", s.ID, h.Sum(nil))
	}

	err = rows.Err()
	if err != nil {
		t.Fatalf("rows.Err() Error - %v", err)
	}

	t.Log("Done:", scans)
}

func TestIssue56(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping test in short mode.")
	}

	var schema = `
CREATE TABLE IF NOT EXISTS Test (
	A string,
	B string,
	Suppressed bool,
);
CREATE INDEX IF NOT EXISTS aIdx ON Test (A);
CREATE INDEX IF NOT EXISTS bIdx ON Test (B);
`

	RegisterDriver()
	dir, err := ioutil.TempDir("", "ql-test-")
	if err != nil {
		t.Fatal(err)
	}

	defer os.RemoveAll(dir)
	pth := filepath.Join(dir, "test.db")
	db, err := sql.Open("ql", "file://"+pth)
	if err != nil {
		t.Fatal(err)
	}

	defer db.Close()

	tx, err := db.Begin()
	if err != nil {
		t.Fatal(err)
	}

	_, err = tx.Exec(schema)
	if err != nil {
		t.Fatal(err)
	}

	err = tx.Commit()
	if err != nil {
		t.Fatal(err)
	}

	// Open a new transaction and do a SELECT

	tx, err = db.Begin()
	if err != nil {
		t.Fatal(err)
	}

	var id int64
	row := tx.QueryRow("SELECT * FROM Test")
	err = row.Scan(&id) // <-- Blocks here

	switch err {
	case sql.ErrNoRows:
		break
	case nil:
		break
	default:
		t.Fatal(err)
	}

	tx.Rollback()
	return
}

func TestRecordSetRows(t *testing.T) {
	db, err := OpenMem()
	if err != nil {
		t.Fatal(err)
	}

	rss, _, err := db.Run(NewRWCtx(), `
		BEGIN TRANSACTION;
			CREATE TABLE t (i int);
			INSERT INTO t VALUES (1), (2), (3), (4), (5);
		COMMIT;
		SELECT * FROM t ORDER BY i;
	`)
	if err != nil {
		t.Fatal(err)
	}

	tab := []struct {
		limit, offset int
		result        []int64
	}{
		// 0
		{-1, 0, []int64{1, 2, 3, 4, 5}},
		{0, 0, nil},
		{1, 0, []int64{1}},
		{2, 0, []int64{1, 2}},
		{3, 0, []int64{1, 2, 3}},
		// 5
		{4, 0, []int64{1, 2, 3, 4}},
		{5, 0, []int64{1, 2, 3, 4, 5}},
		{6, 0, []int64{1, 2, 3, 4, 5}},
		{-1, 0, []int64{1, 2, 3, 4, 5}},
		{-1, 1, []int64{2, 3, 4, 5}},
		// 10
		{-1, 2, []int64{3, 4, 5}},
		{-1, 3, []int64{4, 5}},
		{-1, 4, []int64{5}},
		{-1, 5, nil},
		{3, 0, []int64{1, 2, 3}},
		// 15
		{3, 1, []int64{2, 3, 4}},
		{3, 2, []int64{3, 4, 5}},
		{3, 3, []int64{4, 5}},
		{3, 4, []int64{5}},
		{3, 5, nil},
		// 20
		{-1, 2, []int64{3, 4, 5}},
		{0, 2, nil},
		{1, 2, []int64{3}},
		{2, 2, []int64{3, 4}},
		{3, 2, []int64{3, 4, 5}},
		// 25
		{4, 2, []int64{3, 4, 5}},
	}

	rs := rss[0]
	for iTest, test := range tab {
		t.Log(iTest)
		rows, err := rs.Rows(test.limit, test.offset)
		if err != nil {
			t.Fatal(err)
		}

		if g, e := len(rows), len(test.result); g != e {
			t.Log(rows, test.result)
			t.Fatal(g, e)
		}

		for i, row := range rows {
			if g, e := len(row), 1; g != e {
				t.Fatal(i, g, i)
			}

			if g, e := row[0], test.result[i]; g != e {
				t.Fatal(i, g, e)
			}
		}
	}
}

func TestRecordFirst(t *testing.T) {
	q := MustCompile("SELECT * FROM t WHERE i > $1 ORDER BY i;")
	db, err := OpenMem()
	if err != nil {
		t.Fatal(err)
	}

	if _, _, err = db.Run(NewRWCtx(), `
		BEGIN TRANSACTION;
			CREATE TABLE t (i int);
			INSERT INTO t VALUES (1), (2), (3), (4), (5);
		COMMIT;
	`); err != nil {
		t.Fatal(err)
	}

	tab := []struct {
		par    int64
		result int64
	}{
		{-1, 1},
		{0, 1},
		{1, 2},
		{2, 3},
		{3, 4},
		{4, 5},
		{5, -1},
	}

	for iTest, test := range tab {
		t.Log(iTest)
		rss, _, err := db.Execute(nil, q, test.par)
		if err != nil {
			t.Fatal(err)
		}

		row, err := rss[0].FirstRow()
		if err != nil {
			t.Fatal(err)
		}

		switch {
		case test.result < 0:
			if row != nil {
				t.Fatal(row)
			}
		default:
			if row == nil {
				t.Fatal(row)
			}

			if g, e := len(row), 1; g != e {
				t.Fatal(g, e)
			}

			if g, e := row[0], test.result; g != e {
				t.Fatal(g, e)
			}
		}
	}
}

var issue63 = MustCompile(`
BEGIN TRANSACTION;
	CREATE TABLE Forecast (WeatherProvider string, Timestamp time, MinTemp int32, MaxTemp int32);
	INSERT INTO Forecast VALUES ("dwd.de", now(), 20, 22);
COMMIT;
SELECT * FROM Forecast WHERE Timestamp > 0;`)

func TestIssue63(t *testing.T) {
	db, err := OpenMem()
	if err != nil {
		t.Fatal(err)
	}

	rs, _, err := db.Execute(NewRWCtx(), issue63)
	if err != nil {
		t.Fatal(err)
	}

	if _, err = rs[0].Rows(-1, 0); err == nil {
		t.Fatal(err)
	}

	t.Log(err)
	if g, e := strings.Contains(err.Error(), "invalid operation"), true; g != e {
		t.Fatal(g, e)
	}

	if g, e := strings.Contains(err.Error(), "mismatched types time.Time and int64"), true; g != e {
		t.Fatal(g, e)
	}
}

const issue66Src = `
BEGIN TRANSACTION;
	CREATE TABLE t (i int);
	CREATE UNIQUE INDEX x ON t (i);
	INSERT INTO t VALUES (1), (1);
COMMIT;`

var issue66 = MustCompile(issue66Src)

func TestIssue66Mem(t *testing.T) {
	db, err := OpenMem()
	if err != nil {
		t.Fatal(err)
	}

	_, _, err = db.Execute(NewRWCtx(), issue66)
	if err == nil {
		t.Fatal(err)
	}

	t.Log(err)
}

func TestIssue66File(t *testing.T) {
	dir, err := ioutil.TempDir("", "ql-test-")
	if err != nil {
		t.Fatal(err)
	}

	defer os.RemoveAll(dir)

	db, err := OpenFile(filepath.Join(dir, "test.db"), &Options{CanCreate: true})
	if err != nil {
		t.Fatal(err)
	}

	defer db.Close()

	_, _, err = db.Execute(NewRWCtx(), issue66)
	if err == nil {
		t.Fatal(err)
	}

	t.Log(err)
}

func TestIssue66MemDriver(t *testing.T) {
	RegisterMemDriver()
	db, err := sql.Open("ql-mem", "TestIssue66MemDriver-"+fmt.Sprintf("%d", time.Now().UnixNano()))
	if err != nil {
		t.Fatal(err)
	}

	defer db.Close()

	tx, err := db.Begin()
	if err != nil {
		t.Fatal(err)
	}

	if _, err = tx.Exec(issue66Src); err == nil {
		t.Fatal(err)
	}

	t.Log(err)
}

func TestIssue66FileDriver(t *testing.T) {
	RegisterDriver()
	dir, err := ioutil.TempDir("", "ql-test-")
	if err != nil {
		t.Fatal(err)
	}

	defer os.RemoveAll(dir)

	db, err := sql.Open("ql", filepath.Join(dir, "TestIssue66MemDriver"))
	if err != nil {
		t.Fatal(err)
	}

	defer db.Close()

	tx, err := db.Begin()
	if err != nil {
		t.Fatal(err)
	}

	if _, err = tx.Exec(issue66Src); err == nil {
		t.Fatal(err)
	}

	t.Log(err)
}

func Example_lIKE() {
	db, err := OpenMem()
	if err != nil {
		panic(err)
	}

	rss, _, err := db.Run(NewRWCtx(), `
        BEGIN TRANSACTION;
            CREATE TABLE t (i int, s string);
            INSERT INTO t VALUES
            	(1, "seafood"),
            	(2, "A fool on the hill"),
            	(3, NULL),
            	(4, "barbaz"),
            	(5, "foobar"),
            ;
        COMMIT;
        
        SELECT * FROM t WHERE s LIKE "foo" ORDER BY i;
        SELECT * FROM t WHERE s LIKE "^bar" ORDER BY i;
        SELECT * FROM t WHERE s LIKE "bar$" ORDER BY i;
        SELECT * FROM t WHERE !(s LIKE "foo") ORDER BY i;`,
	)
	if err != nil {
		panic(err)
	}

	for _, rs := range rss {
		if err := rs.Do(false, func(data []interface{}) (bool, error) {
			fmt.Println(data)
			return true, nil
		}); err != nil {
			panic(err)
		}
		fmt.Println("----")
	}
	// Output:
	// [1 seafood]
	// [2 A fool on the hill]
	// [5 foobar]
	// ----
	// [4 barbaz]
	// ----
	// [5 foobar]
	// ----
	// [4 barbaz]
	// ----
}

func TestIssue73(t *testing.T) {
	if testing.Short() {
		t.Skip("skipping test in short mode.")
	}

	RegisterDriver()
	dir, err := ioutil.TempDir("", "ql-test-")
	if err != nil {
		t.Fatal(err)
	}

	defer os.RemoveAll(dir)
	pth := filepath.Join(dir, "test.db")

	for i := 0; i < 10; i++ {
		var db *sql.DB
		var tx *sql.Tx
		var err error
		var row *sql.Row
		var name string

		if db, err = sql.Open("ql", pth); err != nil {
			t.Fatal("sql.Open: ", err)
		}

		t.Log("Call to db.Begin()")
		if tx, err = db.Begin(); err != nil {
			t.Fatal("db.Begin: ", err)
		}

		t.Log("Call to tx.QueryRow()")
		row = tx.QueryRow(`SELECT Name FROM __Table`)
		t.Log("Call to tx.Commit()")
		if err = tx.Commit(); err != nil {
			t.Fatal("tx.Commit: ", err)
		}

		row.Scan(&name)
		t.Log("name: ", name)
	}
}

func Example_id() {
	db, err := OpenMem()
	if err != nil {
		panic(err)
	}

	rss, _, err := db.Run(NewRWCtx(), `
	BEGIN TRANSACTION;
		CREATE TABLE foo (i int);
		INSERT INTO foo VALUES (10), (20);
		CREATE TABLE bar (fooID int, s string);
		INSERT INTO bar SELECT id(), "ten" FROM foo WHERE i == 10;
		INSERT INTO bar SELECT id(), "twenty" FROM foo WHERE i == 20;
	COMMIT;
	SELECT *
	FROM foo, bar
	WHERE bar.fooID == id(foo)
	ORDER BY id(foo);`,
	)
	if err != nil {
		panic(err)
	}

	for _, rs := range rss {
		if err := rs.Do(false, func(data []interface{}) (bool, error) {
			fmt.Println(data)
			return true, nil
		}); err != nil {
			panic(err)
		}
		fmt.Println("----")
	}
	// Output:
	// [10 1 ten]
	// [20 2 twenty]
	// ----
}

func eqRows(a, b [][]interface{}) bool {
	if len(a) != len(b) {
		return false
	}

	for i, rowa := range a {
		rowb := b[i]
		if len(rowa) != len(rowb) {
			return false
		}

		for j, va := range rowa {
			if va != rowb[j] {
				return false
			}
		}
	}
	return true
}

func TestInPredicateBug(t *testing.T) {
	db, err := OpenMem()
	if err != nil {
		t.Fatal(err)
	}

	if _, _, err := db.Run(NewRWCtx(), `
	BEGIN TRANSACTION;
		CREATE TABLE all (i int);
		INSERT INTO all VALUES (0), (1), (2), (3), (4), (5), (6), (7), (8), (9);
		CREATE TABLE even (i int);
		INSERT INTO even VALUES (0), (2), (4), (6), (8);
	COMMIT;
	`); err != nil {
		t.Fatal(err)
	}

	q := MustCompile(`SELECT * FROM all WHERE i IN (SELECT * FROM even) ORDER BY i`)
	rs, _, err := db.Execute(nil, q)
	if err != nil {
		t.Fatal(err)
	}

	rows, err := rs[0].Rows(-1, 0)
	if err != nil {
		t.Fatal(err)
	}

	if g, e := rows, [][]interface{}{{int64(0)}, {int64(2)}, {int64(4)}, {int64(6)}, {int64(8)}}; !eqRows(g, e) {
		t.Fatalf("\n%v\n%v", g, e)
	}

	if _, _, err := db.Run(NewRWCtx(), `
	BEGIN TRANSACTION;
		TRUNCATE TABLE even;
		INSERT INTO even VALUES (1), (3), (5);
	COMMIT;
	`); err != nil {
		t.Fatal(err)
	}

	if rs, _, err = db.Execute(nil, q); err != nil {
		t.Fatal(err)
	}

	if rows, err = rs[0].Rows(-1, 0); err != nil {
		t.Fatal(err)
	}

	if g, e := rows, [][]interface{}{{int64(1)}, {int64(3)}, {int64(5)}}; !eqRows(g, e) {
		t.Fatalf("\n%v\n%v", g, e)
	}
}

func testMentionedColumns(s stmt) (err error) {
	defer func() {
		if e := recover(); e != nil {
			switch x := e.(type) {
			case error:
				err = x
			default:
				err = fmt.Errorf("error: %v", e)
			}
		}
	}()

	switch x := s.(type) {
	case
		*alterTableAddStmt,
		*alterTableDropColumnStmt,
		beginTransactionStmt,
		*createTableStmt,
		commitStmt,
		*dropIndexStmt,
		*dropTableStmt,
		*explainStmt,
		rollbackStmt,
		*truncateTableStmt:
		// nop
	case *createIndexStmt:
		for _, e := range x.exprList {
			mentionedColumns(e)
		}
	case *deleteStmt:
		if e := x.where; e != nil {
			mentionedColumns(e)
		}
	case *insertIntoStmt:
		for _, ll := range x.lists {
			for _, e := range ll {
				mentionedColumns(e)
			}
		}
	case *selectStmt:
		for _, f := range x.flds {
			mentionedColumns(f.expr)
		}
		if l := x.limit; l != nil {
			mentionedColumns(l.expr)
		}
		if o := x.offset; o != nil {
			mentionedColumns(o.expr)
		}
		if o := x.order; o != nil {
			for _, e := range o.by {
				mentionedColumns(e)
			}
		}
		if w := x.where; w != nil {
			mentionedColumns(w.expr)
		}
	case *updateStmt:
		for _, v := range x.list {
			mentionedColumns(v.expr)
		}
		if e := x.where; e != nil {
			mentionedColumns(e)
		}
	default:
		panic("internal error 056")
	}
	return nil
}

const (
	issue99RowsToInsert = 100
	issue99Cycles       = 100
)

var (
	fieldsIssue99 = []string{
		"Datacenter",
		"Name",
		"Address",
		"Health",
		"C0",
		"C1",
		"C2",
		"C3",
		"C4",
		"C5",
		"C6",
		"C7",
		"C8",
		"C9",
		"C10",
		"C11",
		"C12",
		"C13",
		"C14",
		"C15",
		"C16",
		"C17",
		"C18",
		"C19",
		"C20",
		"C21",
		"C22",
		"C23",
		"C24",
		"C25",
		"C26",
		"C27",
		"C28",
		"C29",
		"C30",
		"C31",
		"C32",
		"C33",
		"C34",
		"C35",
		"C36",
		"C37",
		"C38",
		"C39",
		"C40",
		"C41",
		"C42",
		"C43",
		"C44",
		"C45",
		"C46",
		"C47",
		"C48",
		"C49",
		"C50",
		"C51",
		"C52",
		"C53",
		"C54",
		"C55",
		"C56",
		"C57",
		"C58",
		"C59",
		"C60",
		"C61",
		"C62",
		"C63",
		"C64",
		"C65",
		"C66",
		"C67",
		"C68",
		"C69",
		"C70",
		"C71",
		"C72",
		"C73",
		"C74",
		"C75",
		"C76",
		"C77",
		"C78",
		"C79",
		"C80",
		"C81",
		"C82",
		"C83",
		"C84",
		"C85",
		"C86",
		"C87",
		"C88",
		"C89",
		"C90",
		"C91",
		"C92",
		"C93",
		"C94",
		"C95",
		"C96",
		"C97",
		"C98",
		"C99",
	}

	valuesIssue99 = make([]interface{}, len(fieldsIssue99))
)

func init() {
	for i := range valuesIssue99 {
		s := ""
		for _, v := range rand.Perm(32) {
			s += string('0' + v)
		}
		valuesIssue99[i] = s
	}
	valuesIssue99[3] = true
}

func createTablesIssue99(db *sql.DB) error {
	tx, err := db.Begin()
	if err != nil {
		return err
	}

	if _, err = tx.Exec(`
		DROP TABLE IF EXISTS Node;
		CREATE TABLE Node (
			Datacenter string,
			Name string,
			Address string,
			Health bool,
			C0 string DEFAULT "",
			C1 string DEFAULT "",
			C2 string DEFAULT "",
			C3 string DEFAULT "",
			C4 string DEFAULT "",
			C5 string DEFAULT "",
			C6 string DEFAULT "",
			C7 string DEFAULT "",
			C8 string DEFAULT "",
			C9 string DEFAULT "",
			C10 string DEFAULT "",
			C11 string DEFAULT "",
			C12 string DEFAULT "",
			C13 string DEFAULT "",
			C14 string DEFAULT "",
			C15 string DEFAULT "",
			C16 string DEFAULT "",
			C17 string DEFAULT "",
			C18 string DEFAULT "",
			C19 string DEFAULT "",
			C20 string DEFAULT "",
			C21 string DEFAULT "",
			C22 string DEFAULT "",
			C23 string DEFAULT "",
			C24 string DEFAULT "",
			C25 string DEFAULT "",
			C26 string DEFAULT "",
			C27 string DEFAULT "",
			C28 string DEFAULT "",
			C29 string DEFAULT "",
			C30 string DEFAULT "",
			C31 string DEFAULT "",
			C32 string DEFAULT "",
			C33 string DEFAULT "",
			C34 string DEFAULT "",
			C35 string DEFAULT "",
			C36 string DEFAULT "",
			C37 string DEFAULT "",
			C38 string DEFAULT "",
			C39 string DEFAULT "",
			C40 string DEFAULT "",
			C41 string DEFAULT "",
			C42 string DEFAULT "",
			C43 string DEFAULT "",
			C44 string DEFAULT "",
			C45 string DEFAULT "",
			C46 string DEFAULT "",
			C47 string DEFAULT "",
			C48 string DEFAULT "",
			C49 string DEFAULT "",
			C50 string DEFAULT "",
			C51 string DEFAULT "",
			C52 string DEFAULT "",
			C53 string DEFAULT "",
			C54 string DEFAULT "",
			C55 string DEFAULT "",
			C56 string DEFAULT "",
			C57 string DEFAULT "",
			C58 string DEFAULT "",
			C59 string DEFAULT "",
			C60 string DEFAULT "",
			C61 string DEFAULT "",
			C62 string DEFAULT "",
			C63 string DEFAULT "",
			C64 string DEFAULT "",
			C65 string DEFAULT "",
			C66 string DEFAULT "",
			C67 string DEFAULT "",
			C68 string DEFAULT "",
			C69 string DEFAULT "",
			C70 string DEFAULT "",
			C71 string DEFAULT "",
			C72 string DEFAULT "",
			C73 string DEFAULT "",
			C74 string DEFAULT "",
			C75 string DEFAULT "",
			C76 string DEFAULT "",
			C77 string DEFAULT "",
			C78 string DEFAULT "",
			C79 string DEFAULT "",
			C80 string DEFAULT "",
			C81 string DEFAULT "",
			C82 string DEFAULT "",
			C83 string DEFAULT "",
			C84 string DEFAULT "",
			C85 string DEFAULT "",
			C86 string DEFAULT "",
			C87 string DEFAULT "",
			C88 string DEFAULT "",
			C89 string DEFAULT "",
			C90 string DEFAULT "",
			C91 string DEFAULT "",
			C92 string DEFAULT "",
			C93 string DEFAULT "",
			C94 string DEFAULT "",
			C95 string DEFAULT "",
			C96 string DEFAULT "",
			C97 string DEFAULT "",
			C98 string DEFAULT "",
			C99 string DEFAULT "",
    		);`); err != nil {
		return err
	}

	return tx.Commit()
}

func issue99Fill(db *sql.DB) (int, error) {
	tx, err := db.Begin()
	if err != nil {
		return -1, err
	}

	sql := "INSERT INTO Node (" + strings.Join(fieldsIssue99, ",") + ") VALUES ($1, $2, $3, $4"
	for i := range valuesIssue99 {
		if i > 3 {
			sql += ", $" + strconv.Itoa(i+1)
		}
	}
	sql += ")"

	stmt, err := tx.Prepare(sql)
	if err != nil {
		return 0, err
	}

	for i := 0; i < issue99RowsToInsert; i++ {
		if _, err = stmt.Exec(valuesIssue99...); err != nil {
			return 0, err
		}
	}

	return issue99RowsToInsert, tx.Commit()
}

func testIssue99(tb testing.TB, db *sql.DB) int {
	sum := 0
	for i := 0; i < issue99Cycles; i++ {
		if err := createTablesIssue99(db); err != nil {
			tb.Fatal(err)
		}

		n2, err := issue99Fill(db)
		if err != nil {
			tb.Fatal(err)
		}

		sum += n2
	}
	return sum
}

var benchmarkIssue99 sync.Once

func BenchmarkIssue99(b *testing.B) {
	if testing.Verbose() {
		benchProlog(b)
		benchmarkIssue99.Do(func() {
			b.Logf(`1 op == (Re)create a 100+ column table, fill it with %d records. Repeat %d times.

`, issue99RowsToInsert, issue99Cycles)
		})
	}
	RegisterMemDriver()
	db, err := sql.Open("ql-mem", "issue99")
	if err != nil {
		b.Fatal(err)
	}

	b.ResetTimer()
	recs := 0
	for i := 0; i < b.N; i++ {
		recs = testIssue99(b, db)
	}
	b.SetBytes(int64(recs) * benchScale)
}

func TestIssue108(t *testing.T) {
	db, err := OpenMem()
	if err != nil {
		t.Fatal(err)
	}

	setup := `BEGIN TRANSACTION;
CREATE TABLE people (name string NOT NULL);
INSERT INTO people VALUES ("alice"), ("bob");
`
	ctx := NewRWCtx()
	_, _, err = db.Run(ctx, setup)
	if err != nil {
		t.Fatal(err)
	}

	rs, _, err := db.Run(ctx, "SELECT count() FROM people;")
	if err != nil {
		t.Fatal(err)
	}

	row, err := rs[0].FirstRow() // Used to block forever.
	if err != nil {
		t.Fatal(err)
	}

	n, ok := row[0].(int64)
	if !ok || n != 2 {
		t.Fatal(n, 2)
	}

	_, _, err = db.Run(ctx, "COMMIT;")
	if err != nil {
		t.Fatal(err)
	}
}

type issue109 struct {
	*testing.T
	db *DB
}

func (t issue109) test(doIndex bool) {
	t.Logf("Use index: %v", doIndex)
	var err error
	if t.db, err = OpenMem(); err != nil {
		t.Fatal(err)
	}

	if _, _, err := t.db.Run(NewRWCtx(), `
		BEGIN TRANSACTION;
			CREATE TABLE people (name string NOT NULL);
			CREATE TABLE awards (name string NOT NULL);
			CREATE TABLE people_awards (person_id int NOT NULL, award_id int NOT NULL);
		COMMIT;
	`); err != nil {
		t.Fatal(err)
	}

	if doIndex {
		t.createBuggyIndex()
	}

	pid1 := t.createPerson("alice")

	aid1 := t.createAward("awesome")
	aid2 := t.createAward("best")

	zeroFullJoinCount := t.countFullJoin(pid1)
	if zeroFullJoinCount != 0 {
		t.Fatal(zeroFullJoinCount, "Incorrect full join count before creating records")
	}

	t.insertPersonAward(pid1, aid1)
	t.insertPersonAward(pid1, aid2)

	initialFullJoinCount := t.countFullJoin(pid1)
	if initialFullJoinCount != 2 {
		t.Fatal(initialFullJoinCount, "Incorrect full join count before deleting records")
	}

	initialNumJoinRecords := t.countJoinRecords()
	if initialNumJoinRecords != 2 {
		t.Fatal(initialNumJoinRecords, "Incorrect number of join records before deleting records")
	}

	t.deletePersonAwards(pid1)

	afterNumJoinRecords := t.countJoinRecords()
	if afterNumJoinRecords != 0 {
		t.Fatal(afterNumJoinRecords, "Incorrect number of join records after deleting records")
	}

	afterFullJoinCount := t.countFullJoin(pid1)
	if afterFullJoinCount != 0 {
		t.Fatal(afterFullJoinCount, "Incorrect full join count after deleting records")
	}

	t.Logf("OK")
}

func (t issue109) createBuggyIndex() {
	if _, _, err := t.db.Run(NewRWCtx(), `
		BEGIN TRANSACTION;
			CREATE INDEX people_awards_person_id ON people_awards (person_id);
		COMMIT;
	`); err != nil {
		t.Fatal(err)
	}
	t.Log("CREATE INDEX people_awards_person_id ON people_awards (person_id);")
}

func (t issue109) createPerson(name string) int64 {
	ctx := NewRWCtx()
	_, _, err := t.db.Run(ctx, `
		BEGIN TRANSACTION;
			INSERT INTO people(name) VALUES ($1);
		COMMIT;`,
		name,
	)
	if err != nil {
		t.Fatal(err)
	}

	t.Logf("INSERT INTO people(name) VALUES (%q); -> ID %v", name, ctx.LastInsertID)
	return ctx.LastInsertID
}

func (t issue109) createAward(name string) int64 {
	ctx := NewRWCtx()
	_, _, err := t.db.Run(ctx, `
		BEGIN TRANSACTION;
			INSERT INTO awards(name) VALUES ($1);
		COMMIT`,
		name,
	)
	if err != nil {
		t.Fatal(err)
	}

	t.Logf("INSERT INTO awards(name) VALUES (%q); -> ID %v", name, ctx.LastInsertID)
	return ctx.LastInsertID
}

func (t issue109) countFullJoin(personID int64) int {
	stmt := `
		SELECT
			*
		FROM
			awards
		FULL JOIN
			people_awards 
		ON
			id(awards) == people_awards.award_id
		WHERE
			people_awards.person_id == $1
	`
	rs, _, err := t.db.Run(nil, "explain "+stmt, personID)
	if err != nil {
		t.Fatal(err)
	}

	rows, err := rs[0].Rows(-1, 0)
	if err != nil {
		t.Fatal(err)
	}

	t.Log("----")
	for _, v := range rows {
		t.Log(v)
	}

	if rs, _, err = t.db.Run(nil, stmt, personID); err != nil {
		t.Fatal(err)
	}

	if rows, err = rs[0].Rows(-1, 0); err != nil {
		t.Fatal(err)
	}

	for i, v := range rows {
		t.Logf("%v/%v: %v", i, len(rows), v)
	}
	t.Log("----")
	return len(rows)
}

func (t issue109) insertPersonAward(personID, awardID int64) {
	ctx := NewRWCtx()
	_, _, err := t.db.Run(ctx, `
		BEGIN TRANSACTION;
			INSERT INTO people_awards(person_id, award_id) VALUES ($1, $2);
		COMMIT;`,
		personID, awardID,
	)
	if err != nil {
		t.Fatal(err)
	}
	t.Logf("INSERT INTO people_awards(person_id, award_id) VALUES (%v, %v);", personID, awardID)
}

func (t issue109) countJoinRecords() int64 {
	rs, _, err := t.db.Run(nil, `
		SELECT
			count()
		FROM
			people_awards;	
	`)
	if err != nil {
		t.Fatal(err)
	}

	row, err := rs[0].FirstRow()
	if err != nil {
		t.Fatal(err)
	}

	return row[0].(int64)
}

func (t issue109) deletePersonAwards(personID int64) {
	ctx := NewRWCtx()
	_, _, err := t.db.Run(ctx, `
		BEGIN TRANSACTION;
			DELETE FROM people_awards WHERE person_id == $1;
		COMMIT`,
		personID,
	)
	if err != nil {
		t.Fatal(err)
	}

	if ctx.RowsAffected != 2 {
		t.Fatal("Did not delete rows as expected")
	}
	t.Logf("DELETE FROM people_awards WHERE person_id == %v;", personID)
}

func TestIssue109(t *testing.T) {
	(issue109{T: t}).test(false)
	(issue109{T: t}).test(true)
}

// https://github.com/cznic/ql/issues/142
func TestIssue142(t *testing.T) {
	cwd, err := os.Getwd()
	if err != nil {
		t.Fatal(err)
	}

	defer os.Chdir(cwd)

	wd, err := ioutil.TempDir("", "ql-test-issue-142")
	if err != nil {
		t.Fatal(err)
	}

	defer os.RemoveAll(wd)

	if err := os.Chdir(wd); err != nil {
		t.Fatal(err)
	}

	RegisterDriver()
	for _, nm := range []string{"test.db", "./test.db", "another.db"} {
		t.Log(nm)
		db, err := sql.Open("ql", nm)
		if err != nil {
			t.Fatal(err)
		}

		tx, err := db.Begin()
		if err != nil {
			t.Fatal(err)
		}

		if _, err := tx.Exec("drop table if exists t; create table t (c int)"); err != nil {
			t.Fatal(err)
		}

		if err := tx.Commit(); err != nil {
			t.Fatal(err)
		}

		if err := db.Close(); err != nil {
			t.Fatal(err)
		}

		fn := filepath.Join(wd, nm)
		fi, err := os.Stat(fn)
		if err != nil {
			t.Fatal(err)
		}

		t.Log(fn, fi.Size())
		if fi.Size() == 0 {
			t.Fatal("DB is empty")
		}
	}
}