Replacing Atomic Table

Doris supports atomic replacement operations between two tables, applicable only to OLAP tables.

Applicable Scenarios

Sometimes, users need to rewrite table data, but deleting and then importing the data would result in a period of unavailability. In such cases, users can create a new table with the same structure using the CREATE TABLE LIKE statement, import the new data into the new table, and then perform an atomic replacement of the old table. For partition-level atomic overwrite operations, refer to the temporary partition documentation.

Syntax

ALTER TABLE [db.]tbl1 REPLACE WITH TABLE tbl2
[PROPERTIES('swap' = 'true')];

Replace table tbl1 with table tbl2.

If the swap parameter is true, after the replacement, the data in tbl1 will be the original data in tbl2, and the data in tbl2 will be the original data in tbl1, meaning the data in the two tables will be swapped.

If the swap parameter is false, after the replacement, the data in tbl1 will be the original data in tbl2, and tbl2 will be deleted.

Principle

The table replacement function turns the following set of operations into an atomic operation.

Assuming table A is replaced with table B, and swap is true, the operations are as follows:

1. Rename table B to table A.
2. Rename table A to table B.

If swap is false, the operations are as follows:

1. Delete table A.
2. Rename table B to table A.

Notes

• If the swap parameter is false, the replaced table (table A) will be deleted and cannot be recovered.
• The replacement operation can only occur between two OLAP tables and does not check if the table structures are consistent.
• The replacement operation will not change the original permission settings, as permission checks are based on table names.