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ddl: address comment.

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This commit is contained in:
qiuyesuifeng
2015-11-10 17:21:46 +08:00
parent 0f744899c5
commit c210aafc9f
2 changed files with 10 additions and 10 deletions
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10
ddl/column.go
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@ -305,11 +305,11 @@ func (d *ddl) onDropColumn(t *meta.Meta, job *model.Job) error {
}
// How to backfill column data in reorganization state?
// 1, Generate a snapshot with special version.
// 2, Traverse the snapshot, get every row in the table.
// 3, For one row, if the row has been already deleted, skip to next row.
// 4, If not deleted, check whether column data has existed, if existed, skip to next row.
// 5, If column data doesn't exist, backfill the column with default value and then continue to handle next row.
// 1. Generate a snapshot with special version.
// 2. Traverse the snapshot, get every row in the table.
// 3. For one row, if the row has been already deleted, skip to next row.
// 4. If not deleted, check whether column data has existed, if existed, skip to next row.
// 5. If column data doesn't exist, backfill the column with default value and then continue to handle next row.
func (d *ddl) backfillColumn(t table.Table, columnInfo *model.ColumnInfo, reorgInfo *reorgInfo) error {
seekHandle := reorgInfo.Handle
version := reorgInfo.SnapshotVer

10
ddl/index.go
View File

@ -332,11 +332,11 @@ func fetchRowColVals(txn kv.Transaction, t table.Table, handle int64, indexInfo
const maxBatchSize = 1024
// How to add index in reorganization state?
// 1, Generate a snapshot with special version.
// 2, Traverse the snapshot, get every row in the table.
// 3, For one row, if the row has been already deleted, skip to next row.
// 4, If not deleted, check whether index has existed, if existed, skip to next row.
// 5, If index doesn't exist, create the index and then continue to handle next row.
// 1. Generate a snapshot with special version.
// 2. Traverse the snapshot, get every row in the table.
// 3. For one row, if the row has been already deleted, skip to next row.
// 4. If not deleted, check whether index has existed, if existed, skip to next row.
// 5. If index doesn't exist, create the index and then continue to handle next row.
func (d *ddl) addTableIndex(t table.Table, indexInfo *model.IndexInfo, reorgInfo *reorgInfo) error {
seekHandle := reorgInfo.Handle
version := reorgInfo.SnapshotVer