Golang sql.TestDisableTableLeases函数代码示例

// TestSchemaChangeCommandsWithPendingMutations tests how schema change
// commands behave when they are referencing schema elements that are
// mutations that are not yet live.
func TestSchemaChangeCommandsWithPendingMutations(t *testing.T) {
	defer leaktest.AfterTest(t)()
	// The descriptor changes made must have an immediate effect
	// so disable leases on tables.
	defer csql.TestDisableTableLeases()()
	// Disable external processing of mutations.
	params, _ := createTestServerParams()
	params.Knobs.SQLSchemaChangeManager = &csql.SchemaChangeManagerTestingKnobs{
		AsyncSchemaChangerExecNotification: schemaChangeManagerDisabled,
	}
	server, sqlDB, kvDB := serverutils.StartServer(t, params)
	defer server.Stopper().Stop()

	if _, err := sqlDB.Exec(`
CREATE DATABASE t;
CREATE TABLE t.test (a CHAR PRIMARY KEY, b CHAR, c CHAR, INDEX foo (c));
`); err != nil {
		t.Fatal(err)
	}

	// Read table descriptor
	tableDesc := sqlbase.GetTableDescriptor(kvDB, "t", "test")

	mt := mutationTest{
		T:         t,
		kvDB:      kvDB,
		sqlDB:     sqlDB,
		tableDesc: tableDesc,
	}

	// Test CREATE INDEX in the presence of mutations.

	// Add index DROP mutation "foo""
	mt.writeIndexMutation("foo", sqlbase.DescriptorMutation{Direction: sqlbase.DescriptorMutation_DROP})
	if _, err := sqlDB.Exec(`CREATE INDEX foo ON t.test (c)`); !testutils.IsError(err, `index "foo" being dropped, try again later`) {
		t.Fatal(err)
	}
	// Make "foo" live.
	mt.makeMutationsActive()

	// "foo" is being added.
	mt.writeIndexMutation("foo", sqlbase.DescriptorMutation{Direction: sqlbase.DescriptorMutation_ADD})
	if _, err := sqlDB.Exec(`CREATE INDEX foo ON t.test (c)`); !testutils.IsError(err, `duplicate index name: "foo"`) {
		t.Fatal(err)
	}
	// Make "foo" live.
	mt.makeMutationsActive()
	// Add column DROP mutation "b"
	mt.writeColumnMutation("b", sqlbase.DescriptorMutation{Direction: sqlbase.DescriptorMutation_DROP})
	if _, err := sqlDB.Exec(`CREATE INDEX bar ON t.test (b)`); !testutils.IsError(err, `index "bar" contains unknown column "b"`) {
		t.Fatal(err)
	}
	// Make "b" live.
	mt.makeMutationsActive()
	// "b" is being added.
	mt.writeColumnMutation("b", sqlbase.DescriptorMutation{Direction: sqlbase.DescriptorMutation_ADD})
	// An index referencing a column mutation that is being added
	// is allowed to be added.
	if _, err := sqlDB.Exec(`CREATE INDEX bar ON t.test (b)`); err != nil {
		t.Fatal(err)
	}
	// Make "b" live.
	mt.makeMutationsActive()

	// Test DROP INDEX in the presence of mutations.

	// Add index DROP mutation "foo""
	mt.writeIndexMutation("foo", sqlbase.DescriptorMutation{Direction: sqlbase.DescriptorMutation_DROP})
	// Noop.
	if _, err := sqlDB.Exec(`DROP INDEX [email protected]`); err != nil {
		t.Fatal(err)
	}
	// Make "foo" live.
	mt.makeMutationsActive()
	// "foo" is being added.
	mt.writeIndexMutation("foo", sqlbase.DescriptorMutation{Direction: sqlbase.DescriptorMutation_ADD})
	if _, err := sqlDB.Exec(`DROP INDEX [email protected]`); !testutils.IsError(err, `index "foo" in the middle of being added, try again later`) {
		t.Fatal(err)
	}
	// Make "foo" live.
	mt.makeMutationsActive()
	// Test ALTER TABLE ADD/DROP column in the presence of mutations.

	// Add column DROP mutation "b"
	mt.writeColumnMutation("b", sqlbase.DescriptorMutation{Direction: sqlbase.DescriptorMutation_DROP})
	if _, err := sqlDB.Exec(`ALTER TABLE t.test ADD b CHAR`); !testutils.IsError(err, `column "b" being dropped, try again later`) {
		t.Fatal(err)
	}
	// Noop.
	if _, err := sqlDB.Exec(`ALTER TABLE t.test DROP b`); err != nil {
		t.Fatal(err)
	}
	// Make "b" live.
	mt.makeMutationsActive()
	// "b" is being added.
	mt.writeColumnMutation("b", sqlbase.DescriptorMutation{Direction: sqlbase.DescriptorMutation_ADD})
	if _, err := sqlDB.Exec(`ALTER TABLE t.test ADD b CHAR`); !testutils.IsError(err, `duplicate column name: "b"`) {
//.........这里部分代码省略.........

func TestOperationsWithIndexMutation(t *testing.T) {
	defer leaktest.AfterTest(t)()
	// The descriptor changes made must have an immediate effect.
	defer csql.TestDisableTableLeases()()
	// Disable external processing of mutations.
	params, _ := createTestServerParams()
	params.Knobs.SQLSchemaChangeManager = &csql.SchemaChangeManagerTestingKnobs{
		AsyncSchemaChangerExecNotification: schemaChangeManagerDisabled,
	}
	server, sqlDB, kvDB := serverutils.StartServer(t, params)
	defer server.Stopper().Stop()

	if _, err := sqlDB.Exec(`
CREATE DATABASE t;
CREATE TABLE t.test (k CHAR PRIMARY KEY, v CHAR, INDEX foo (v));
`); err != nil {
		t.Fatal(err)
	}

	// read table descriptor
	tableDesc := sqlbase.GetTableDescriptor(kvDB, "t", "test")

	mTest := mutationTest{
		T:         t,
		kvDB:      kvDB,
		sqlDB:     sqlDB,
		tableDesc: tableDesc,
	}

	starQuery := `SELECT * FROM t.test`
	indexQuery := `SELECT v FROM [email protected]`
	// See the effect of the operations depending on the state.
	for _, state := range []sqlbase.DescriptorMutation_State{sqlbase.DescriptorMutation_DELETE_ONLY, sqlbase.DescriptorMutation_WRITE_ONLY} {
		// Init table with some entries.
		if _, err := sqlDB.Exec(`TRUNCATE TABLE t.test`); err != nil {
			t.Fatal(err)
		}
		initRows := [][]string{{"a", "z"}, {"b", "y"}}
		for _, row := range initRows {
			if _, err := sqlDB.Exec(`INSERT INTO t.test VALUES ($1, $2)`, row[0], row[1]); err != nil {
				t.Fatal(err)
			}
		}
		_ = mTest.checkQueryResponse(starQuery, initRows)
		// Index foo is visible.
		_ = mTest.checkQueryResponse(indexQuery, [][]string{{"y"}, {"z"}})

		// Index foo is invisible once it's a mutation.
		mTest.writeIndexMutation("foo", sqlbase.DescriptorMutation{State: state})
		if _, err := sqlDB.Query(indexQuery); !testutils.IsError(err, `index "foo" not found`) {
			t.Fatal(err)
		}

		// Insert a new entry.
		if _, err := sqlDB.Exec(`INSERT INTO t.test VALUES ('c', 'x')`); err != nil {
			t.Fatal(err)
		}
		_ = mTest.checkQueryResponse(starQuery, [][]string{{"a", "z"}, {"b", "y"}, {"c", "x"}})

		// Make index "foo" live so that we can read it.
		mTest.makeMutationsActive()
		if state == sqlbase.DescriptorMutation_DELETE_ONLY {
			// "x" didn't get added to the index.
			_ = mTest.checkQueryResponse(indexQuery, [][]string{{"y"}, {"z"}})
		} else {
			// "x" got added to the index.
			_ = mTest.checkQueryResponse(indexQuery, [][]string{{"x"}, {"y"}, {"z"}})
		}

		// Make "foo" a mutation.
		mTest.writeIndexMutation("foo", sqlbase.DescriptorMutation{State: state})
		// Update.
		if _, err := sqlDB.Exec(`UPDATE t.test SET v = 'w' WHERE k = 'c'`); err != nil {
			t.Fatal(err)
		}
		// Update "v" to its current value "z" in row "a".
		if _, err := sqlDB.Exec(`UPDATE t.test SET v = 'z' WHERE k = 'a'`); err != nil {
			t.Fatal(err)
		}
		_ = mTest.checkQueryResponse(starQuery, [][]string{{"a", "z"}, {"b", "y"}, {"c", "w"}})

		// Make index "foo" live so that we can read it.
		mTest.makeMutationsActive()
		if state == sqlbase.DescriptorMutation_DELETE_ONLY {
			// updating "x" -> "w" is a noop on the index,
			// updating "z" -> "z" results in "z" being deleted from the index.
			_ = mTest.checkQueryResponse(indexQuery, [][]string{{"y"}, {"z"}})
		} else {
			// updating "x" -> "w" results in the index updating from "x" -> "w",
			// updating "z" -> "z" is a noop on the index.
			_ = mTest.checkQueryResponse(indexQuery, [][]string{{"w"}, {"y"}, {"z"}})
		}

		// Make "foo" a mutation.
		mTest.writeIndexMutation("foo", sqlbase.DescriptorMutation{State: state})
		// Delete row "b".
		if _, err := sqlDB.Exec(`DELETE FROM t.test WHERE k = 'b'`); err != nil {
			t.Fatal(err)
		}
		_ = mTest.checkQueryResponse(starQuery, [][]string{{"a", "z"}, {"c", "w"}})
//.........这里部分代码省略.........

// TestOperationsWithUniqueColumnMutation tests all the operations while an
// index mutation refers to a column mutation.
func TestOperationsWithUniqueColumnMutation(t *testing.T) {
	defer leaktest.AfterTest(t)()
	// The descriptor changes made must have an immediate effect
	// so disable leases on tables.
	defer csql.TestDisableTableLeases()()
	// Disable external processing of mutations.
	params, _ := createTestServerParams()
	params.Knobs.SQLSchemaChangeManager = &csql.SchemaChangeManagerTestingKnobs{
		AsyncSchemaChangerExecNotification: schemaChangeManagerDisabled,
	}
	server, sqlDB, kvDB := serverutils.StartServer(t, params)
	defer server.Stopper().Stop()

	// Create a table with column i and an index on v and i.
	if _, err := sqlDB.Exec(`
CREATE DATABASE t;
CREATE TABLE t.test (k CHAR PRIMARY KEY, v CHAR, i CHAR, INDEX foo (i, v));
`); err != nil {
		t.Fatal(err)
	}

	// read table descriptor
	tableDesc := sqlbase.GetTableDescriptor(kvDB, "t", "test")

	mTest := mutationTest{
		T:         t,
		kvDB:      kvDB,
		sqlDB:     sqlDB,
		tableDesc: tableDesc,
	}

	starQuery := `SELECT * FROM t.test`
	indexQuery := `SELECT i FROM [email protected]`
	// Run the tests for both states for a column and an index.
	for _, state := range []sqlbase.DescriptorMutation_State{
		sqlbase.DescriptorMutation_DELETE_ONLY,
		sqlbase.DescriptorMutation_WRITE_ONLY,
	} {
		for _, idxState := range []sqlbase.DescriptorMutation_State{
			sqlbase.DescriptorMutation_DELETE_ONLY,
			sqlbase.DescriptorMutation_WRITE_ONLY,
		} {
			// Ignore the impossible column in DELETE_ONLY state while index
			// is in the WRITE_ONLY state.
			if state == sqlbase.DescriptorMutation_DELETE_ONLY &&
				idxState == sqlbase.DescriptorMutation_WRITE_ONLY {
				continue
			}
			// Init table to start state.
			if _, err := sqlDB.Exec(`TRUNCATE TABLE t.test`); err != nil {
				t.Fatal(err)
			}
			initRows := [][]string{{"a", "z", "q"}, {"b", "y", "r"}}
			for _, row := range initRows {
				if _, err := sqlDB.Exec(`INSERT INTO t.test VALUES ($1, $2, $3)`, row[0], row[1], row[2]); err != nil {
					t.Fatal(err)
				}
			}
			// Check that the table only contains the initRows.
			_ = mTest.checkQueryResponse(starQuery, initRows)

			// Add index "foo" as a mutation.
			mTest.writeIndexMutation("foo", sqlbase.DescriptorMutation{State: idxState})
			// Make column "i" a mutation.
			mTest.writeColumnMutation("i", sqlbase.DescriptorMutation{State: state})

			// Insert a row into the table.
			if _, err := sqlDB.Exec(`INSERT INTO t.test VALUES ('c', 'x')`); err != nil {
				t.Error(err)
			}

			// Make column "i" and index "foo" live.
			mTest.makeMutationsActive()
			// column "i" has no entry.
			_ = mTest.checkQueryResponse(starQuery, [][]string{{"a", "z", "q"}, {"b", "y", "r"}, {"c", "x", "NULL"}})
			if idxState == sqlbase.DescriptorMutation_DELETE_ONLY {
				// No index entry for row "c"
				_ = mTest.checkQueryResponse(indexQuery, [][]string{{"q"}, {"r"}})
			} else {
				// Index entry for row "c"
				_ = mTest.checkQueryResponse(indexQuery, [][]string{{"NULL"}, {"q"}, {"r"}})
			}

			// Add index "foo" as a mutation.
			mTest.writeIndexMutation("foo", sqlbase.DescriptorMutation{State: idxState})
			// Make column "i" a mutation.
			mTest.writeColumnMutation("i", sqlbase.DescriptorMutation{State: state})

			// Updating column "i" for a row fails.
			if _, err := sqlDB.Exec(`UPDATE t.test SET (v, i) = ('u', 'u') WHERE k = 'a'`); !testutils.IsError(err, `column "i" does not exist`) {
				t.Error(err)
			}

			// Update a row without specifying  mutation column "i".
			if _, err := sqlDB.Exec(`UPDATE t.test SET v = 'u' WHERE k = 'a'`); err != nil {
				t.Error(err)
			}
			// Make column "i" and index "foo" live.
//.........这里部分代码省略.........

func TestCommandsWithPendingMutations(t *testing.T) {
	defer leaktest.AfterTest(t)
	// The descriptor changes made must have an immediate effect
	// so disable leases on tables.
	defer csql.TestDisableTableLeases()()
	// Disable external processing of mutations.
	defer csql.TestDisableAsyncSchemaChangeExec()()
	server, sqlDB, kvDB := setup(t)
	defer cleanup(server, sqlDB)

	if _, err := sqlDB.Exec(`
CREATE DATABASE t;
CREATE TABLE t.test (a CHAR PRIMARY KEY, b CHAR, c CHAR, INDEX foo (c));
`); err != nil {
		t.Fatal(err)
	}

	// Read table descriptor
	nameKey := csql.MakeNameMetadataKey(keys.MaxReservedDescID+1, "test")
	gr, err := kvDB.Get(nameKey)
	if err != nil {
		t.Fatal(err)
	}
	if !gr.Exists() {
		t.Fatalf("Name entry %q does not exist", nameKey)
	}
	descKey := csql.MakeDescMetadataKey(csql.ID(gr.ValueInt()))
	desc := &csql.Descriptor{}
	if err := kvDB.GetProto(descKey, desc); err != nil {
		t.Fatal(err)
	}

	mt := mutationTest{
		T:       t,
		kvDB:    kvDB,
		sqlDB:   sqlDB,
		descKey: descKey,
		desc:    desc,
	}

	// Test CREATE INDEX in the presence of mutations.

	// Add index DROP mutation "foo""
	mt.writeIndexMutation("foo", csql.DescriptorMutation{Direction: csql.DescriptorMutation_DROP})
	if _, err := sqlDB.Exec(`CREATE INDEX foo ON t.test (c)`); !testutils.IsError(err, `index "foo" being dropped, try again later`) {
		t.Fatal(err)
	}
	// Make "foo" live.
	mt.makeMutationsActive()

	// "foo" is being added.
	mt.writeIndexMutation("foo", csql.DescriptorMutation{Direction: csql.DescriptorMutation_ADD})
	if _, err := sqlDB.Exec(`CREATE INDEX foo ON t.test (c)`); !testutils.IsError(err, `duplicate index name: "foo"`) {
		t.Fatal(err)
	}
	// Make "foo" live.
	mt.makeMutationsActive()
	// Add column DROP mutation "b"
	mt.writeColumnMutation("b", csql.DescriptorMutation{Direction: csql.DescriptorMutation_DROP})
	if _, err := sqlDB.Exec(`CREATE INDEX bar ON t.test (b)`); !testutils.IsError(err, `index "bar" contains unknown column "b"`) {
		t.Fatal(err)
	}
	// Make "b" live.
	mt.makeMutationsActive()
	// "b" is being added.
	mt.writeColumnMutation("b", csql.DescriptorMutation{Direction: csql.DescriptorMutation_ADD})
	// An index referencing a column mutation that is being added
	// is allowed to be added.
	if _, err := sqlDB.Exec(`CREATE INDEX bar ON t.test (b)`); err != nil {
		t.Fatal(err)
	}
	// Make "b" live.
	mt.makeMutationsActive()

	// Test DROP INDEX in the presence of mutations.

	// Add index DROP mutation "foo""
	mt.writeIndexMutation("foo", csql.DescriptorMutation{Direction: csql.DescriptorMutation_DROP})
	// Noop.
	if _, err := sqlDB.Exec(`DROP INDEX [email protected]`); err != nil {
		t.Fatal(err)
	}
	// Make "foo" live.
	mt.makeMutationsActive()
	// "foo" is being added.
	mt.writeIndexMutation("foo", csql.DescriptorMutation{Direction: csql.DescriptorMutation_ADD})
	if _, err := sqlDB.Exec(`DROP INDEX [email protected]`); !testutils.IsError(err, `index "foo" in the middle of being added, try again later`) {
		t.Fatal(err)
	}
	// Make "foo" live.
	mt.makeMutationsActive()
	// Test ALTER TABLE ADD/DROP column in the presence of mutations.

	// Add column DROP mutation "b"
	mt.writeColumnMutation("b", csql.DescriptorMutation{Direction: csql.DescriptorMutation_DROP})
	if _, err := sqlDB.Exec(`ALTER TABLE t.test ADD b CHAR`); !testutils.IsError(err, `column "b" being dropped, try again later`) {
		t.Fatal(err)
	}
	// Noop.
	if _, err := sqlDB.Exec(`ALTER TABLE t.test DROP b`); err != nil {
//.........这里部分代码省略.........

func TestOperationsWithColumnMutation(t *testing.T) {
	defer leaktest.AfterTest(t)()
	// The descriptor changes made must have an immediate effect
	// so disable leases on tables.
	defer csql.TestDisableTableLeases()()
	// Disable external processing of mutations.
	params, _ := createTestServerParams()
	params.Knobs.SQLSchemaChangeManager = &csql.SchemaChangeManagerTestingKnobs{
		AsyncSchemaChangerExecNotification: schemaChangeManagerDisabled,
	}
	server, sqlDB, kvDB := serverutils.StartServer(t, params)
	defer server.Stopper().Stop()

	if _, err := sqlDB.Exec(`
CREATE DATABASE t;
CREATE TABLE t.test (k CHAR PRIMARY KEY, v CHAR, i CHAR DEFAULT 'i');
`); err != nil {
		t.Fatal(err)
	}

	// read table descriptor
	tableDesc := sqlbase.GetTableDescriptor(kvDB, "t", "test")

	mTest := mutationTest{
		T:         t,
		kvDB:      kvDB,
		sqlDB:     sqlDB,
		tableDesc: tableDesc,
	}

	starQuery := `SELECT * FROM t.test`
	// Run the tests for both states.
	for _, state := range []sqlbase.DescriptorMutation_State{sqlbase.DescriptorMutation_DELETE_ONLY, sqlbase.DescriptorMutation_WRITE_ONLY} {
		// Init table to start state.
		if _, err := sqlDB.Exec(`TRUNCATE TABLE t.test`); err != nil {
			t.Fatal(err)
		}
		initRows := [][]string{{"a", "z", "q"}}
		for _, row := range initRows {
			if _, err := sqlDB.Exec(`INSERT INTO t.test VALUES ($1, $2, $3)`, row[0], row[1], row[2]); err != nil {
				t.Fatal(err)
			}
		}
		// Check that the table only contains the initRows.
		_ = mTest.checkQueryResponse(starQuery, initRows)

		// Add column "i" as a mutation.
		mTest.writeColumnMutation("i", sqlbase.DescriptorMutation{State: state})
		// A direct read of column "i" fails.
		if _, err := sqlDB.Query(`SELECT i FROM t.test`); err == nil {
			t.Fatalf("Read succeeded despite column being in %v state", sqlbase.DescriptorMutation{State: state})
		}
		// The table only contains columns "k" and "v".
		_ = mTest.checkQueryResponse(starQuery, [][]string{{"a", "z"}})

		// The column backfill uses Put instead of CPut because it depends on
		// an INSERT of a column in the WRITE_ONLY state failing. These two
		// tests guarantee that.

		// Inserting a row into the table while specifying column "i" results in an error.
		if _, err := sqlDB.Exec(`INSERT INTO t.test (k, v, i) VALUES ('b', 'y', 'i')`); !testutils.IsError(err, `column "i" does not exist`) {
			t.Fatal(err)
		}
		// Repeating the same without specifying the columns results in a different error.
		if _, err := sqlDB.Exec(`INSERT INTO t.test VALUES ('b', 'y', 'i')`); !testutils.IsError(err, "INSERT error: table t.test has 2 columns but 3 values were supplied") {
			t.Fatal(err)
		}
		// Make column "i" live so that it is read.
		mTest.makeMutationsActive()
		// Check that we can read all the rows and columns.
		_ = mTest.checkQueryResponse(starQuery, initRows)

		var afterInsert, afterUpdate, afterDelete [][]string
		if state == sqlbase.DescriptorMutation_DELETE_ONLY {
			// The default value of "i" for column "i" is not written.
			afterInsert = [][]string{{"a", "z", "q"}, {"c", "x", "NULL"}}
			// Update is a noop for column "i".
			afterUpdate = [][]string{{"a", "u", "q"}, {"c", "x", "NULL"}}
			// Delete also deletes column "i".
			afterDelete = [][]string{{"c", "x", "NULL"}}
		} else {
			// The default value of "i" for column "i" is written.
			afterInsert = [][]string{{"a", "z", "q"}, {"c", "x", "i"}}
			// Update is a noop for column "i".
			afterUpdate = [][]string{{"a", "u", "q"}, {"c", "x", "i"}}
			// Delete also deletes column "i".
			afterDelete = [][]string{{"c", "x", "i"}}
		}
		// Make column "i" a mutation.
		mTest.writeColumnMutation("i", sqlbase.DescriptorMutation{State: state})
		// Insert a row into the table.
		if _, err := sqlDB.Exec(`INSERT INTO t.test VALUES ('c', 'x')`); err != nil {
			t.Fatal(err)
		}
		// Make column "i" live so that it is read.
		mTest.makeMutationsActive()
		// Notice that the default value of "i" is only written when the
		// descriptor is in the WRITE_ONLY state.
		_ = mTest.checkQueryResponse(starQuery, afterInsert)

//.........这里部分代码省略.........

func TestOperationsWithColumnMutation(t *testing.T) {
	defer leaktest.AfterTest(t)
	// The descriptor changes made must have an immediate effect
	// so disable leases on tables.
	defer csql.TestDisableTableLeases()()
	// Disable external processing of mutations.
	defer csql.TestDisableAsyncSchemaChangeExec()()
	server, sqlDB, kvDB := setup(t)
	defer cleanup(server, sqlDB)

	if _, err := sqlDB.Exec(`
CREATE DATABASE t;
CREATE TABLE t.test (k CHAR PRIMARY KEY, v CHAR, i CHAR DEFAULT 'i');
`); err != nil {
		t.Fatal(err)
	}

	// read table descriptor
	nameKey := csql.MakeNameMetadataKey(keys.MaxReservedDescID+1, "test")
	gr, err := kvDB.Get(nameKey)
	if err != nil {
		t.Fatal(err)
	}
	if !gr.Exists() {
		t.Fatalf("Name entry %q does not exist", nameKey)
	}
	descKey := csql.MakeDescMetadataKey(csql.ID(gr.ValueInt()))
	desc := &csql.Descriptor{}
	if err := kvDB.GetProto(descKey, desc); err != nil {
		t.Fatal(err)
	}

	mTest := mutationTest{
		T:       t,
		kvDB:    kvDB,
		sqlDB:   sqlDB,
		descKey: descKey,
		desc:    desc,
	}

	starQuery := `SELECT * FROM t.test`
	// Run the tests for both states.
	for _, state := range []csql.DescriptorMutation_State{csql.DescriptorMutation_DELETE_ONLY, csql.DescriptorMutation_WRITE_ONLY} {
		// Init table to start state.
		if _, err := sqlDB.Exec(`TRUNCATE TABLE t.test`); err != nil {
			t.Fatal(err)
		}
		initRows := [][]string{{"a", "z", "q"}}
		for _, row := range initRows {
			if _, err := sqlDB.Exec(`INSERT INTO t.test VALUES ($1, $2, $3)`, row[0], row[1], row[2]); err != nil {
				t.Fatal(err)
			}
		}
		// Check that the table only contains the initRows.
		_ = mTest.checkQueryResponse(starQuery, initRows)

		// Add column "i" as a mutation.
		mTest.writeColumnMutation("i", csql.DescriptorMutation{State: state})
		// A direct read of column "i" fails.
		if _, err := sqlDB.Query(`SELECT i FROM t.test`); err == nil {
			t.Fatalf("Read succeeded despite column being in %v state", csql.DescriptorMutation{State: state})
		}
		// The table only contains columns "k" and "v".
		_ = mTest.checkQueryResponse(starQuery, [][]string{{"a", "z"}})

		// Inserting a row into the table while specifying column "i" results in an error.
		if _, err := sqlDB.Exec(`INSERT INTO t.test (k, v, i) VALUES ('b', 'y', 'i')`); !testutils.IsError(err, `column "i" does not exist`) {
			t.Fatal(err)
		}
		// Repeating the same without specifying the columns results in a different error.
		if _, err := sqlDB.Exec(`INSERT INTO t.test VALUES ('b', 'y', 'i')`); !testutils.IsError(err, "INSERT has more expressions than target columns: 3/2") {
			t.Fatal(err)
		}
		// Make column "i" live so that it is read.
		mTest.makeMutationsActive()
		// Check that we can read all the rows and columns.
		_ = mTest.checkQueryResponse(starQuery, initRows)

		var afterInsert, afterUpdate, afterDelete [][]string
		if state == csql.DescriptorMutation_DELETE_ONLY {
			// The default value of "i" for column "i" is not written.
			afterInsert = [][]string{{"a", "z", "q"}, {"c", "x", "NULL"}}
			// Update is a noop for column "i".
			afterUpdate = [][]string{{"a", "u", "q"}, {"c", "x", "NULL"}}
			// Delete also deletes column "i".
			afterDelete = [][]string{{"c", "x", "NULL"}}
		} else {
			// The default value of "i" for column "i" is written.
			afterInsert = [][]string{{"a", "z", "q"}, {"c", "x", "i"}}
			// Update is a noop for column "i".
			afterUpdate = [][]string{{"a", "u", "q"}, {"c", "x", "i"}}
			// Delete also deletes column "i".
			afterDelete = [][]string{{"c", "x", "i"}}
		}
		// Make column "i" a mutation.
		mTest.writeColumnMutation("i", csql.DescriptorMutation{State: state})
		// Insert a row into the table.
		if _, err := sqlDB.Exec(`INSERT INTO t.test VALUES ('c', 'x')`); err != nil {
			t.Fatal(err)
		}
//.........这里部分代码省略.........

func TestOperationsWithIndexMutation(t *testing.T) {
	defer leaktest.AfterTest(t)
	// The descriptor changes made must have an immediate effect.
	defer csql.TestDisableTableLeases()()
	// Disable external processing of mutations.
	defer csql.TestDisableAsyncSchemaChangeExec()()
	server, sqlDB, kvDB := setup(t)
	defer cleanup(server, sqlDB)

	if _, err := sqlDB.Exec(`
CREATE DATABASE t;
CREATE TABLE t.test (k CHAR PRIMARY KEY, v CHAR, INDEX foo (v));
`); err != nil {
		t.Fatal(err)
	}

	// read table descriptor
	nameKey := csql.MakeNameMetadataKey(keys.MaxReservedDescID+1, "test")
	gr, err := kvDB.Get(nameKey)
	if err != nil {
		t.Fatal(err)
	}
	if !gr.Exists() {
		t.Fatalf("Name entry %q does not exist", nameKey)
	}
	descKey := csql.MakeDescMetadataKey(csql.ID(gr.ValueInt()))
	desc := &csql.Descriptor{}
	if err := kvDB.GetProto(descKey, desc); err != nil {
		t.Fatal(err)
	}

	mTest := mutationTest{
		T:       t,
		kvDB:    kvDB,
		sqlDB:   sqlDB,
		descKey: descKey,
		desc:    desc,
	}

	starQuery := `SELECT * FROM t.test`
	indexQuery := `SELECT * FROM [email protected]`
	// See the effect of the operations depending on the state.
	for _, state := range []csql.DescriptorMutation_State{csql.DescriptorMutation_DELETE_ONLY, csql.DescriptorMutation_WRITE_ONLY} {
		// Init table with some entries.
		if _, err := sqlDB.Exec(`TRUNCATE TABLE t.test`); err != nil {
			t.Fatal(err)
		}
		initRows := [][]string{{"a", "z"}, {"b", "y"}}
		for _, row := range initRows {
			if _, err := sqlDB.Exec(`INSERT INTO t.test VALUES ($1, $2)`, row[0], row[1]); err != nil {
				t.Fatal(err)
			}
		}
		_ = mTest.checkQueryResponse(starQuery, initRows)
		// Index foo is visible.
		_ = mTest.checkQueryResponse(indexQuery, [][]string{{"y"}, {"z"}})

		// Index foo is invisible once it's a mutation.
		mTest.writeIndexMutation("foo", csql.DescriptorMutation{State: state})
		if _, err := sqlDB.Query(indexQuery); !testutils.IsError(err, `index "foo" not found`) {
			t.Fatal(err)
		}

		// Insert a new entry.
		if _, err := sqlDB.Exec(`INSERT INTO t.test VALUES ('c', 'x')`); err != nil {
			t.Fatal(err)
		}
		_ = mTest.checkQueryResponse(starQuery, [][]string{{"a", "z"}, {"b", "y"}, {"c", "x"}})

		// Make index "foo" live so that we can read it.
		mTest.makeMutationsActive()
		if state == csql.DescriptorMutation_DELETE_ONLY {
			// "x" didn't get added to the index.
			_ = mTest.checkQueryResponse(indexQuery, [][]string{{"y"}, {"z"}})
		} else {
			// "x" got added to the index.
			_ = mTest.checkQueryResponse(indexQuery, [][]string{{"x"}, {"y"}, {"z"}})
		}

		// Make "foo" a mutation.
		mTest.writeIndexMutation("foo", csql.DescriptorMutation{State: state})
		// Update.
		if _, err := sqlDB.Exec(`UPDATE t.test SET v = 'w' WHERE k = 'c'`); err != nil {
			t.Fatal(err)
		}
		// Update "v" to its current value "z" in row "a".
		if _, err := sqlDB.Exec(`UPDATE t.test SET v = 'z' WHERE k = 'a'`); err != nil {
			t.Fatal(err)
		}
		_ = mTest.checkQueryResponse(starQuery, [][]string{{"a", "z"}, {"b", "y"}, {"c", "w"}})

		// Make index "foo" live so that we can read it.
		mTest.makeMutationsActive()
		if state == csql.DescriptorMutation_DELETE_ONLY {
			// updating "x" -> "w" is a noop on the index,
			// updating "z" -> "z" results in "z" being deleted from the index.
			_ = mTest.checkQueryResponse(indexQuery, [][]string{{"y"}, {"z"}})
		} else {
			// updating "x" -> "w" results in the index updating from "x" -> "w",
			// updating "z" -> "z" is a noop on the index.
//.........这里部分代码省略.........

// TestOperationsWithUniqueColumnMutation tests all the operations while an
// index mutation refers to a column mutation.
func TestOperationsWithUniqueColumnMutation(t *testing.T) {
	defer leaktest.AfterTest(t)()
	// The descriptor changes made must have an immediate effect
	// so disable leases on tables.
	defer csql.TestDisableTableLeases()()
	// Disable external processing of mutations.
	ctx, _ := createTestServerContext()
	ctx.TestingKnobs.SQLSchemaChangeManager = &csql.SchemaChangeManagerTestingKnobs{
		AsyncSchemaChangerExecNotification: schemaChangeManagerDisabled,
	}
	server, sqlDB, kvDB := setupWithContext(t, &ctx)
	defer cleanup(server, sqlDB)

	// Create a table with column i and an index on v and i.
	if _, err := sqlDB.Exec(`
CREATE DATABASE t;
CREATE TABLE t.test (k CHAR PRIMARY KEY, v CHAR, i CHAR, INDEX foo (i, v));
`); err != nil {
		t.Fatal(err)
	}

	// read table descriptor
	nameKey := sqlbase.MakeNameMetadataKey(keys.MaxReservedDescID+1, "test")
	gr, err := kvDB.Get(nameKey)
	if err != nil {
		t.Fatal(err)
	}
	if !gr.Exists() {
		t.Fatalf("Name entry %q does not exist", nameKey)
	}
	descKey := sqlbase.MakeDescMetadataKey(sqlbase.ID(gr.ValueInt()))
	desc := &sqlbase.Descriptor{}
	if err := kvDB.GetProto(descKey, desc); err != nil {
		t.Fatal(err)
	}

	mTest := mutationTest{
		T:       t,
		kvDB:    kvDB,
		sqlDB:   sqlDB,
		descKey: descKey,
		desc:    desc,
	}

	starQuery := `SELECT * FROM t.test`
	indexQuery := `SELECT i FROM [email protected]`
	// Run the tests for both states.
	for _, state := range []sqlbase.DescriptorMutation_State{
		sqlbase.DescriptorMutation_DELETE_ONLY,
		sqlbase.DescriptorMutation_WRITE_ONLY,
	} {
		// Init table to start state.
		if _, err := sqlDB.Exec(`TRUNCATE TABLE t.test`); err != nil {
			t.Fatal(err)
		}
		initRows := [][]string{{"a", "z", "q"}}
		for _, row := range initRows {
			if _, err := sqlDB.Exec(`INSERT INTO t.test VALUES ($1, $2, $3)`, row[0], row[1], row[2]); err != nil {
				t.Fatal(err)
			}
		}
		// Check that the table only contains the initRows.
		_ = mTest.checkQueryResponse(starQuery, initRows)

		// Add index "foo" as a mutation.
		mTest.writeIndexMutation("foo", sqlbase.DescriptorMutation{State: state})
		// Make column "i" a mutation.
		mTest.writeColumnMutation("i", sqlbase.DescriptorMutation{State: state})

		// Insert a row into the table.
		if _, err := sqlDB.Exec(`INSERT INTO t.test VALUES ('c', 'x')`); err != nil {
			t.Error(err)
		}

		// Make column "i" and index "foo" live.
		mTest.makeMutationsActive()
		// column "i" has no entry.
		_ = mTest.checkQueryResponse(starQuery, [][]string{{"a", "z", "q"}, {"c", "x", "NULL"}})
		if state == sqlbase.DescriptorMutation_DELETE_ONLY {
			// No index entry for row "c"
			_ = mTest.checkQueryResponse(indexQuery, [][]string{{"q"}})
		} else {
			// Index entry for row "c"
			_ = mTest.checkQueryResponse(indexQuery, [][]string{{"NULL"}, {"q"}})
		}

		// Add index "foo" as a mutation.
		mTest.writeIndexMutation("foo", sqlbase.DescriptorMutation{State: state})
		// Make column "i" a mutation.
		mTest.writeColumnMutation("i", sqlbase.DescriptorMutation{State: state})

		// Updating column "i" for a row fails.
		if _, err := sqlDB.Exec(`UPDATE t.test SET (v, i) = ('u', 'u') WHERE k = 'a'`); !testutils.IsError(err, `column "i" does not exist`) {
			t.Error(err)
		}

		// TODO(vivek): Fix #6691.
		// Update a row without specifying  mutation column "i".
//.........这里部分代码省略.........

func TestAsyncSchemaChanger(t *testing.T) {
	defer leaktest.AfterTest(t)
	// Disable synchronous schema change execution so
	// the asynchronous schema changer executes all
	// schema changes.
	defer csql.TestDisableSyncSchemaChangeExec()()
	// The descriptor changes made must have an immediate effect
	// so disable leases on tables.
	defer csql.TestDisableTableLeases()()
	server, sqlDB, kvDB := setup(t)
	defer cleanup(server, sqlDB)

	if _, err := sqlDB.Exec(`
CREATE DATABASE t;
CREATE TABLE t.test (k CHAR PRIMARY KEY, v CHAR);
INSERT INTO t.test VALUES ('a', 'b'), ('c', 'd');
`); err != nil {
		t.Fatal(err)
	}

	// Read table descriptor for version.
	nameKey := csql.MakeNameMetadataKey(keys.MaxReservedDescID+1, "test")
	gr, err := kvDB.Get(nameKey)
	if err != nil {
		t.Fatal(err)
	}
	if !gr.Exists() {
		t.Fatalf("Name entry %q does not exist", nameKey)
	}
	descKey := csql.MakeDescMetadataKey(csql.ID(gr.ValueInt()))
	desc := &csql.Descriptor{}
	if err := kvDB.GetProto(descKey, desc); err != nil {
		t.Fatal(err)
	}
	// A long running schema change operation runs through
	// a state machine that increments the version by 3.
	expectedVersion := desc.GetTable().Version + 3

	// Run some schema change
	if _, err := sqlDB.Exec(`
CREATE INDEX foo ON t.test (v)
`); err != nil {
		t.Fatal(err)
	}

	retryOpts := retry.Options{
		InitialBackoff: 20 * time.Millisecond,
		MaxBackoff:     200 * time.Millisecond,
		Multiplier:     2,
	}

	// Wait until index is created.
	for r := retry.Start(retryOpts); r.Next(); {
		if err := kvDB.GetProto(descKey, desc); err != nil {
			t.Fatal(err)
		}
		if len(desc.GetTable().Indexes) == 1 {
			break
		}
	}

	// Ensure that the indexes have been created.
	mTest := mutationTest{
		T:       t,
		kvDB:    kvDB,
		sqlDB:   sqlDB,
		descKey: descKey,
		desc:    desc,
	}
	indexQuery := `SELECT * FROM [email protected]`
	_ = mTest.checkQueryResponse(indexQuery, [][]string{{"b"}, {"d"}})

	// Ensure that the version has been incremented.
	if err := kvDB.GetProto(descKey, desc); err != nil {
		t.Fatal(err)
	}
	newVersion := desc.GetTable().Version
	if newVersion != expectedVersion {
		t.Fatalf("bad version; e = %d, v = %d", expectedVersion, newVersion)
	}

	// Apply a schema change that only sets the UpVersion bit.
	expectedVersion = newVersion + 1

	if _, err := sqlDB.Exec(`
ALTER INDEX [email protected] RENAME TO ufo
`); err != nil {
		t.Fatal(err)
	}

	for r := retry.Start(retryOpts); r.Next(); {
		// Ensure that the version gets incremented.
		if err := kvDB.GetProto(descKey, desc); err != nil {
			t.Fatal(err)
		}
		name := desc.GetTable().Indexes[0].Name
		if name != "ufo" {
			t.Fatalf("bad index name %s", name)
		}
		newVersion = desc.GetTable().Version
//.........这里部分代码省略.........

func TestSchemaChangeProcess(t *testing.T) {
	defer leaktest.AfterTest(t)
	// The descriptor changes made must have an immediate effect
	// so disable leases on tables.
	defer csql.TestDisableTableLeases()()
	// Disable external processing of mutations.
	defer csql.TestDisableAsyncSchemaChangeExec()()
	server, sqlDB, kvDB := setup(t)
	defer cleanup(server, sqlDB)
	var id = csql.ID(keys.MaxReservedDescID + 2)
	var node = roachpb.NodeID(2)
	db := server.DB()
	leaseMgr := csql.NewLeaseManager(0, *db, hlc.NewClock(hlc.UnixNano))
	changer := csql.NewSchemaChangerForTesting(id, 0, node, *db, leaseMgr)

	if _, err := sqlDB.Exec(`
CREATE DATABASE t;
CREATE TABLE t.test (k CHAR PRIMARY KEY, v CHAR, INDEX foo(v));
INSERT INTO t.test VALUES ('a', 'b'), ('c', 'd');
`); err != nil {
		t.Fatal(err)
	}

	// Read table descriptor for version.
	nameKey := csql.MakeNameMetadataKey(keys.MaxReservedDescID+1, "test")
	gr, err := kvDB.Get(nameKey)
	if err != nil {
		t.Fatal(err)
	}
	if !gr.Exists() {
		t.Fatalf("Name entry %q does not exist", nameKey)
	}
	descKey := csql.MakeDescMetadataKey(csql.ID(gr.ValueInt()))
	desc := &csql.Descriptor{}

	// Check that MaybeIncrementVersion doesn't increment the version
	// when the up_version bit is not set.
	if err := kvDB.GetProto(descKey, desc); err != nil {
		t.Fatal(err)
	}
	expectedVersion := desc.GetTable().Version

	if err := changer.MaybeIncrementVersion(); err != nil {
		t.Fatal(err)
	}
	if err := kvDB.GetProto(descKey, desc); err != nil {
		t.Fatal(err)
	}
	newVersion := desc.GetTable().Version
	if newVersion != expectedVersion {
		t.Fatalf("bad version; e = %d, v = %d", expectedVersion, newVersion)
	}
	isDone, err := changer.IsDone()
	if err != nil {
		t.Fatal(err)
	}
	if !isDone {
		t.Fatalf("table expected to not have an outstanding schema change: %v", desc.GetTable())
	}

	// Check that MaybeIncrementVersion increments the version
	// correctly.
	expectedVersion++
	desc.GetTable().UpVersion = true
	if err := kvDB.Put(descKey, desc); err != nil {
		t.Fatal(err)
	}
	isDone, err = changer.IsDone()
	if err != nil {
		t.Fatal(err)
	}
	if isDone {
		t.Fatalf("table expected to have an outstanding schema change: %v", desc.GetTable())
	}
	if err := changer.MaybeIncrementVersion(); err != nil {
		t.Fatal(err)
	}
	if err := kvDB.GetProto(descKey, desc); err != nil {
		t.Fatal(err)
	}
	newVersion = desc.GetTable().Version
	if newVersion != expectedVersion {
		t.Fatalf("bad version; e = %d, v = %d", expectedVersion, newVersion)
	}
	isDone, err = changer.IsDone()
	if err != nil {
		t.Fatal(err)
	}
	if !isDone {
		t.Fatalf("table expected to not have an outstanding schema change: %v", desc.GetTable())
	}

	// Check that RunStateMachineBeforeBackfill doesn't do anything
	// if there are no mutations queued.
	if err := changer.RunStateMachineBeforeBackfill(); err != nil {
		t.Fatal(err)
	}
	if err := kvDB.GetProto(descKey, desc); err != nil {
		t.Fatal(err)
	}
//.........这里部分代码省略.........

func TestAsyncSchemaChanger(t *testing.T) {
	defer leaktest.AfterTest(t)()
	// The descriptor changes made must have an immediate effect
	// so disable leases on tables.
	defer csql.TestDisableTableLeases()()
	// Disable synchronous schema change execution so the asynchronous schema
	// changer executes all schema changes.
	params, _ := createTestServerParams()
	params.Knobs = base.TestingKnobs{
		SQLExecutor: &csql.ExecutorTestingKnobs{
			SyncSchemaChangersFilter: func(tscc csql.TestingSchemaChangerCollection) {
				tscc.ClearSchemaChangers()
			},
		},
		SQLSchemaChangeManager: &csql.SchemaChangeManagerTestingKnobs{
			AsyncSchemaChangerExecQuickly: true,
		},
	}
	s, sqlDB, kvDB := serverutils.StartServer(t, params)
	defer s.Stopper().Stop()

	if _, err := sqlDB.Exec(`
CREATE DATABASE t;
CREATE TABLE t.test (k CHAR PRIMARY KEY, v CHAR);
INSERT INTO t.test VALUES ('a', 'b'), ('c', 'd');
`); err != nil {
		t.Fatal(err)
	}

	// Read table descriptor for version.
	tableDesc := sqlbase.GetTableDescriptor(kvDB, "t", "test")

	// A long running schema change operation runs through
	// a state machine that increments the version by 3.
	expectedVersion := tableDesc.Version + 3

	// Run some schema change
	if _, err := sqlDB.Exec(`
CREATE INDEX foo ON t.test (v)
`); err != nil {
		t.Fatal(err)
	}

	retryOpts := retry.Options{
		InitialBackoff: 20 * time.Millisecond,
		MaxBackoff:     200 * time.Millisecond,
		Multiplier:     2,
	}

	// Wait until index is created.
	for r := retry.Start(retryOpts); r.Next(); {
		tableDesc = sqlbase.GetTableDescriptor(kvDB, "t", "test")
		if len(tableDesc.Indexes) == 1 {
			break
		}
	}

	// Ensure that the indexes have been created.
	mTest := mutationTest{
		T:         t,
		kvDB:      kvDB,
		sqlDB:     sqlDB,
		tableDesc: tableDesc,
	}
	indexQuery := `SELECT v FROM [email protected]`
	_ = mTest.checkQueryResponse(indexQuery, [][]string{{"b"}, {"d"}})

	// Ensure that the version has been incremented.
	tableDesc = sqlbase.GetTableDescriptor(kvDB, "t", "test")
	newVersion := tableDesc.Version
	if newVersion != expectedVersion {
		t.Fatalf("bad version; e = %d, v = %d", expectedVersion, newVersion)
	}

	// Apply a schema change that only sets the UpVersion bit.
	expectedVersion = newVersion + 1

	if _, err := sqlDB.Exec(`
ALTER INDEX [email protected] RENAME TO ufo
`); err != nil {
		t.Fatal(err)
	}

	for r := retry.Start(retryOpts); r.Next(); {
		// Ensure that the version gets incremented.
		tableDesc = sqlbase.GetTableDescriptor(kvDB, "t", "test")
		name := tableDesc.Indexes[0].Name
		if name != "ufo" {
			t.Fatalf("bad index name %s", name)
		}
		newVersion = tableDesc.Version
		if newVersion == expectedVersion {
			break
		}
	}

	// Run many schema changes simultaneously and check
	// that they all get executed.
	count := 5
	for i := 0; i < count; i++ {
//.........这里部分代码省略.........

func TestSchemaChangeProcess(t *testing.T) {
	defer leaktest.AfterTest(t)()
	// The descriptor changes made must have an immediate effect
	// so disable leases on tables.
	defer csql.TestDisableTableLeases()()

	params, _ := createTestServerParams()
	// Disable external processing of mutations.
	params.Knobs.SQLSchemaChangeManager = &csql.SchemaChangeManagerTestingKnobs{
		AsyncSchemaChangerExecNotification: schemaChangeManagerDisabled,
	}
	s, sqlDB, kvDB := serverutils.StartServer(t, params)
	defer s.Stopper().Stop()

	var id = sqlbase.ID(keys.MaxReservedDescID + 2)
	var node = roachpb.NodeID(2)
	stopper := stop.NewStopper()
	leaseMgr := csql.NewLeaseManager(0, *kvDB, hlc.NewClock(hlc.UnixNano), csql.LeaseManagerTestingKnobs{}, stopper)
	defer stopper.Stop()
	changer := csql.NewSchemaChangerForTesting(id, 0, node, *kvDB, leaseMgr)

	if _, err := sqlDB.Exec(`
CREATE DATABASE t;
CREATE TABLE t.test (k CHAR PRIMARY KEY, v CHAR, INDEX foo(v));
INSERT INTO t.test VALUES ('a', 'b'), ('c', 'd');
`); err != nil {
		t.Fatal(err)
	}

	// Read table descriptor for version.
	tableDesc := sqlbase.GetTableDescriptor(kvDB, "t", "test")

	expectedVersion := tableDesc.Version

	desc, err := changer.MaybeIncrementVersion()
	if err != nil {
		t.Fatal(err)
	}
	tableDesc = desc.GetTable()
	newVersion := tableDesc.Version
	if newVersion != expectedVersion {
		t.Fatalf("bad version; e = %d, v = %d", expectedVersion, newVersion)
	}
	isDone, err := changer.IsDone()
	if err != nil {
		t.Fatal(err)
	}
	if !isDone {
		t.Fatalf("table expected to not have an outstanding schema change: %v", tableDesc)
	}

	// Check that MaybeIncrementVersion increments the version
	// correctly.
	expectedVersion++
	tableDesc.UpVersion = true
	if err := kvDB.Put(
		sqlbase.MakeDescMetadataKey(tableDesc.ID),
		sqlbase.WrapDescriptor(tableDesc),
	); err != nil {
		t.Fatal(err)
	}
	isDone, err = changer.IsDone()
	if err != nil {
		t.Fatal(err)
	}
	if isDone {
		t.Fatalf("table expected to have an outstanding schema change: %v", desc.GetTable())
	}
	desc, err = changer.MaybeIncrementVersion()
	if err != nil {
		t.Fatal(err)
	}
	tableDesc = desc.GetTable()
	savedTableDesc := sqlbase.GetTableDescriptor(kvDB, "t", "test")
	newVersion = tableDesc.Version
	if newVersion != expectedVersion {
		t.Fatalf("bad version in returned desc; e = %d, v = %d", expectedVersion, newVersion)
	}
	newVersion = savedTableDesc.Version
	if newVersion != expectedVersion {
		t.Fatalf("bad version in saved desc; e = %d, v = %d", expectedVersion, newVersion)
	}
	isDone, err = changer.IsDone()
	if err != nil {
		t.Fatal(err)
	}
	if !isDone {
		t.Fatalf("table expected to not have an outstanding schema change: %v", tableDesc)
	}

	// Check that RunStateMachineBeforeBackfill doesn't do anything
	// if there are no mutations queued.
	if err := changer.RunStateMachineBeforeBackfill(); err != nil {
		t.Fatal(err)
	}

	tableDesc = sqlbase.GetTableDescriptor(kvDB, "t", "test")
	newVersion = tableDesc.Version
	if newVersion != expectedVersion {
		t.Fatalf("bad version; e = %d, v = %d", expectedVersion, newVersion)
//.........这里部分代码省略.........