func (d *ddl) dropTableIndex(t table.Table, indexInfo *model.IndexInfo) error {
prefix := kv.GenIndexPrefix(t.IndexPrefix(), indexInfo.Name.L)
prefixBytes := []byte(prefix)
keys := make([]string, maxBatchSize)
for {
keys := keys[0:0]
err := kv.RunInNewTxn(d.store, false, func(txn kv.Transaction) error {
iter, err := txn.Seek(prefixBytes)
if err != nil {
return errors.Trace(err)
}
defer iter.Close()
for i := 0; i < maxBatchSize; i++ {
if iter.Valid() && strings.HasPrefix(iter.Key(), prefix) {
keys = append(keys, iter.Key())
err = iter.Next()
if err != nil {
return errors.Trace(err)
}
} else {
break
}
}
return nil
})
// if err or delete no keys, return.
if err != nil || len(keys) == 0 {
return errors.Trace(err)
}
// delete index key one by one
for _, key := range keys {
err = kv.RunInNewTxn(d.store, true, func(txn kv.Transaction) error {
if err := d.isReorgRunnable(txn); err != nil {
return errors.Trace(err)
}
err1 := txn.Delete([]byte(key))
// if key doesn't exist, skip this error.
if err1 != nil && !terror.ErrorEqual(err1, kv.ErrNotExist) {
return errors.Trace(err1)
}
return nil
})
if err != nil {
return errors.Trace(err)
}
}
}
}
func (d *ddl) dropTableIndex(t table.Table, indexInfo *model.IndexInfo) error {
prefix := kv.GenIndexPrefix(t.IndexPrefix(), indexInfo.ID)
err := d.delKeysWithPrefix(prefix)
return errors.Trace(err)
}