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schemadiff: fix index/foreign-key apply scenario (#16698)
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Signed-off-by: Shlomi Noach <[email protected]>
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@shlomi-noach
shlomi-noach authored Sep 4, 2024
1 parent 44f6390 commit 1ed18d0
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Showing 4 changed files with 163 additions and 17 deletions.
2 changes: 1 addition & 1 deletion go/test/endtoend/onlineddl/vrepl_suite/testdata/swap-uk-uk/alter
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Original file line number Diff line number Diff line change
@@ -1 +1 @@
drop key id_uidx, drop key its_uidx, add unique key its2_uidx(i, ts), add unique key id2_uidx(id)
drop key id_uidx, drop key its_uidx, add unique key id2_uidx(id), add unique key its2_uidx(i, ts)
11 changes: 11 additions & 0 deletions go/vt/schemadiff/diff_test.go
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Expand Up @@ -911,6 +911,17 @@ func TestDiffSchemas(t *testing.T) {
"DROP TABLE `t7`",
},
},
{
name: "rename index used by foreign keys",
from: `create table parent (id int primary key); create table t (id int primary key, i int, key i_idx (i), constraint f foreign key (i) references parent(id))`,
to: `create table parent (id int primary key); create table t (id int primary key, i int, key i_alternative (i), constraint f foreign key (i) references parent(id))`,
diffs: []string{
"alter table t rename index i_idx to i_alternative",
},
cdiffs: []string{
"ALTER TABLE `t` RENAME INDEX `i_idx` TO `i_alternative`",
},
},
// Views
{
name: "identical views",
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120 changes: 104 additions & 16 deletions go/vt/schemadiff/table.go
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Original file line number Diff line number Diff line change
Expand Up @@ -1590,6 +1590,21 @@ func (c *CreateTableEntity) diffKeys(alterTable *sqlparser.AlterTable,
t2KeysMap[key.Info.Name.String()] = key
}

// A map of index definition text to lost of key names that have that definition.
// For example, in:
//
// create table t (
// i1 int,
// i2 int,
// key k1 (i1),
// key k2 (i2),
// key k3 (i2)
// )
// We will have:
// - "KEY `` (i1)": ["k1"]
// - "KEY `` (i2)": ["k2", "k3"]
droppedKeysAnonymousDefinitions := map[string]([]string){}

dropKeyStatement := func(info *sqlparser.IndexInfo) *sqlparser.DropKey {
dropKey := &sqlparser.DropKey{}
if info.Type == sqlparser.IndexTypePrimary {
Expand All @@ -1601,14 +1616,25 @@ func (c *CreateTableEntity) diffKeys(alterTable *sqlparser.AlterTable,
return dropKey
}

anonymizedIndexDefinition := func(indexDefinition *sqlparser.IndexDefinition) string {
currentName := indexDefinition.Info.Name
defer func() { indexDefinition.Info.Name = currentName }()
indexDefinition.Info.Name = sqlparser.NewIdentifierCI("")
return sqlparser.CanonicalString(indexDefinition)
}

// evaluate dropped keys
//
dropKeyStatements := map[string]*sqlparser.DropKey{}
for _, t1Key := range t1Keys {
if _, ok := t2KeysMap[t1Key.Info.Name.String()]; !ok {
// column exists in t1 but not in t2, hence it is dropped
dropKey := dropKeyStatement(t1Key.Info)
alterTable.AlterOptions = append(alterTable.AlterOptions, dropKey)
dropKeyStatements[t1Key.Info.Name.String()] = dropKey
annotations.MarkRemoved(sqlparser.CanonicalString(t1Key))

anonymized := anonymizedIndexDefinition(t1Key)
droppedKeysAnonymousDefinitions[anonymized] = append(droppedKeysAnonymousDefinitions[anonymized], t1Key.Info.Name.String())
}
}

Expand Down Expand Up @@ -1644,6 +1670,28 @@ func (c *CreateTableEntity) diffKeys(alterTable *sqlparser.AlterTable,
}
} else {
// key exists in t2 but not in t1, hence it is added

// But wait! As an optimization, if this index has the exact same definition as a previously dropped index,
// then we convert the drop+add statements in to a `RENAME INDEX` statement.
convertedToRename := false
anonymized := anonymizedIndexDefinition(t2Key)
if droppedKeys := droppedKeysAnonymousDefinitions[anonymized]; len(droppedKeys) > 0 {
if dropKey, ok := dropKeyStatements[droppedKeys[0]]; ok {
delete(dropKeyStatements, droppedKeys[0])
droppedKeysAnonymousDefinitions[anonymized] = droppedKeys[1:]
renameIndex := &sqlparser.RenameIndex{
OldName: dropKey.Name,
NewName: t2Key.Info.Name,
}
alterTable.AlterOptions = append(alterTable.AlterOptions, renameIndex)
convertedToRename = true
}
}
if convertedToRename {
continue
}
// End of conversion to RENAME INDEX. Proceed with actual ADD INDEX

addKey := &sqlparser.AddIndexDefinition{
IndexDefinition: t2Key,
}
Expand All @@ -1663,6 +1711,9 @@ func (c *CreateTableEntity) diffKeys(alterTable *sqlparser.AlterTable,
}
}
}
for _, stmt := range dropKeyStatements {
alterTable.AlterOptions = append(alterTable.AlterOptions, stmt)
}
return superfluousFulltextKeys
}

Expand Down Expand Up @@ -2036,12 +2087,14 @@ func sortAlterOptions(diff *AlterTableEntityDiff) {
return 5
case *sqlparser.AddColumns:
return 6
case *sqlparser.AddIndexDefinition:
case *sqlparser.RenameIndex:
return 7
case *sqlparser.AddConstraintDefinition:
case *sqlparser.AddIndexDefinition:
return 8
case sqlparser.TableOptions, *sqlparser.TableOptions:
case *sqlparser.AddConstraintDefinition:
return 9
case sqlparser.TableOptions, *sqlparser.TableOptions:
return 10
default:
return math.MaxInt
}
Expand Down Expand Up @@ -2197,20 +2250,25 @@ func (c *CreateTableEntity) apply(diff *AlterTableEntityDiff) error {
return &ApplyKeyNotFoundError{Table: c.Name(), Key: opt.Name.String()}
}

// Now, if this is a normal key being dropped, let's validate it does not leave any foreign key constraint uncovered
switch opt.Type {
case sqlparser.PrimaryKeyType, sqlparser.NormalKeyType:
for _, cs := range c.CreateTable.TableSpec.Constraints {
fk, ok := cs.Details.(*sqlparser.ForeignKeyDefinition)
if !ok {
continue
}
if !c.columnsCoveredByInOrderIndex(fk.Source) {
return &IndexNeededByForeignKeyError{Table: c.Name(), Key: opt.Name.String()}
}
case *sqlparser.RenameIndex:
// validate no existing key by same name
newKeyName := opt.NewName.String()
for _, index := range c.TableSpec.Indexes {
if strings.EqualFold(index.Info.Name.String(), newKeyName) {
return &ApplyDuplicateKeyError{Table: c.Name(), Key: newKeyName}
}
}

found := false
for _, index := range c.TableSpec.Indexes {
if index.Info.Name.String() == opt.OldName.String() {
index.Info.Name = opt.NewName
found = true
break
}
}
if !found {
return &ApplyKeyNotFoundError{Table: c.Name(), Key: opt.OldName.String()}
}
case *sqlparser.AddIndexDefinition:
// validate no existing key by same name
keyName := opt.IndexDefinition.Info.Name.String()
Expand Down Expand Up @@ -2407,11 +2465,41 @@ func (c *CreateTableEntity) apply(diff *AlterTableEntityDiff) error {
}
return nil
}
// postApplyOptionsIteration runs on all options, after applyAlterOption does.
// Some validations can only take place after all options have been applied.
postApplyOptionsIteration := func(opt sqlparser.AlterOption) error {
switch opt := opt.(type) {
case *sqlparser.DropKey:
// Now, if this is a normal key being dropped, let's validate it does not leave any foreign key constraint uncovered.
// We must have this in `postApplyOptionsIteration` as opposed to `applyAlterOption` because
// this DROP KEY may have been followed by an ADD KEY that covers the foreign key constraint, so it's wrong
// to error out before applying the ADD KEY.
switch opt.Type {
case sqlparser.PrimaryKeyType, sqlparser.NormalKeyType:
for _, cs := range c.CreateTable.TableSpec.Constraints {
fk, ok := cs.Details.(*sqlparser.ForeignKeyDefinition)
if !ok {
continue
}
if !c.columnsCoveredByInOrderIndex(fk.Source) {
return &IndexNeededByForeignKeyError{Table: c.Name(), Key: opt.Name.String()}
}
}
}
}
return nil
}

for _, alterOption := range diff.alterTable.AlterOptions {
if err := applyAlterOption(alterOption); err != nil {
return err
}
}
for _, alterOption := range diff.alterTable.AlterOptions {
if err := postApplyOptionsIteration(alterOption); err != nil {
return err
}
}
if err := c.postApplyNormalize(); err != nil {
return err
}
Expand Down
47 changes: 47 additions & 0 deletions go/vt/schemadiff/table_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -805,6 +805,41 @@ func TestCreateTableDiff(t *testing.T) {
"+ KEY `i_idx3` (`id`)",
},
},
{
name: "reordered and renamed key",
from: "create table t1 (`id` int primary key, i int, key i_idx(i), key i2_idx(i, `id`))",
to: "create table t2 (`id` int primary key, i int, key i2_alternative (`i`, id), key i_idx ( i ) )",
diff: "alter table t1 rename index i2_idx to i2_alternative",
cdiff: "ALTER TABLE `t1` RENAME INDEX `i2_idx` TO `i2_alternative`",
},
{
name: "reordered and renamed keys",
from: "create table t1 (`id` int primary key, i int, key i_idx(i), key i2_idx(i, `id`))",
to: "create table t2 (`id` int primary key, i int, key i2_alternative (`i`, id), key i_alternative ( i ) )",
diff: "alter table t1 rename index i2_idx to i2_alternative, rename index i_idx to i_alternative",
cdiff: "ALTER TABLE `t1` RENAME INDEX `i2_idx` TO `i2_alternative`, RENAME INDEX `i_idx` TO `i_alternative`",
},
{
name: "multiple similar keys, one rename",
from: "create table t1 (`id` int primary key, i int, key i_idx(i), key i2_idx(i))",
to: "create table t2 (`id` int primary key, i int, key i_idx(i), key i2_alternative(i))",
diff: "alter table t1 rename index i2_idx to i2_alternative",
cdiff: "ALTER TABLE `t1` RENAME INDEX `i2_idx` TO `i2_alternative`",
},
{
name: "multiple similar keys, two renames",
from: "create table t1 (`id` int primary key, i int, key i_idx(i), key i2_idx(i))",
to: "create table t2 (`id` int primary key, i int, key i_alternative(i), key i2_alternative(i))",
diff: "alter table t1 rename index i_idx to i_alternative, rename index i2_idx to i2_alternative",
cdiff: "ALTER TABLE `t1` RENAME INDEX `i_idx` TO `i_alternative`, RENAME INDEX `i2_idx` TO `i2_alternative`",
},
{
name: "multiple similar keys, two renames, reorder",
from: "create table t1 (`id` int primary key, i int, key i0 (i, id), key i_idx(i), key i2_idx(i))",
to: "create table t2 (`id` int primary key, i int, key i_alternative(i), key i2_alternative(i), key i0 (i, id))",
diff: "alter table t1 rename index i_idx to i_alternative, rename index i2_idx to i2_alternative",
cdiff: "ALTER TABLE `t1` RENAME INDEX `i_idx` TO `i_alternative`, RENAME INDEX `i2_idx` TO `i2_alternative`",
},
{
name: "key made visible",
from: "create table t1 (`id` int primary key, i int, key i_idx(i) invisible)",
Expand Down Expand Up @@ -2788,6 +2823,18 @@ func TestValidate(t *testing.T) {
alter: "alter table t drop key `i`",
expectErr: &IndexNeededByForeignKeyError{Table: "t", Key: "i"},
},
{
name: "allow drop key when also adding a different index for foreign key constraint",
from: "create table t (id int primary key, i int, key i_idx (i), constraint f foreign key (i) references parent(id))",
alter: "alter table t drop key `i_idx`, add key i_alternative (i)",
to: "create table t (id int primary key, i int, key i_alternative (i), constraint f foreign key (i) references parent(id))",
},
{
name: "allow drop key when also adding a different, longer, index for foreign key constraint",
from: "create table t (id int primary key, i int, key i_idx (i), constraint f foreign key (i) references parent(id))",
alter: "alter table t drop key `i_idx`, add key i_alternative (i, id)",
to: "create table t (id int primary key, i int, key i_alternative (i, id), constraint f foreign key (i) references parent(id))",
},
{
name: "drop key with alternative key for foreign key constraint, 1",
from: "create table t (id int primary key, i int, key i (i), key i2 (i, id), constraint f foreign key (i) references parent(id))",
Expand Down

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