---
{
    "title": "ALTER-TABLE-PROPERTY",
    "language": "en"
}
---

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## ALTER-TABLE-PROPERTY

### Name

ALTER TABLE PROPERTY

### Description

This statement is used to modify the properties of an existing table. This operation is synchronous, and the return of the command indicates the completion of the execution.

grammar:

```sql
ALTER TABLE [database.]table alter_clause;
```

The alter_clause of property supports the following modification methods

1. Modify the bloom filter column of the table

```sql
ALTER TABLE example_db.my_table SET ("bloom_filter_columns"="k1,k2,k3");
```

Can also be incorporated into the schema change operation above (note that the syntax for multiple clauses is slightly different)

```sql
ALTER TABLE example_db.my_table
DROP COLUMN col2
PROPERTIES ("bloom_filter_columns"="k1,k2,k3");
```

2. Modify the Colocate property of the table

```sql
ALTER TABLE example_db.my_table set ("colocate_with" = "t1");
```

3. Change the bucketing method of the table from Hash Distribution to Random Distribution

```sql
ALTER TABLE example_db.my_table set ("distribution_type" = "random");
```

4. Modify the dynamic partition attribute of the table (support adding dynamic partition attribute to the table without dynamic partition attribute)

```sql
ALTER TABLE example_db.my_table set ("dynamic_partition.enable" = "false");
```

If you need to add dynamic partition attributes to tables without dynamic partition attributes, you need to specify all dynamic partition attributes
   (Note: adding dynamic partition attributes is not supported for non-partitioned tables)

```sql
ALTER TABLE example_db.my_table set ("dynamic_partition.enable" = "true", "dynamic_partition.time_unit" = "DAY", "dynamic_partition.end" = "3", "dynamic_partition.prefix" = "p", "dynamic_partition. buckets" = "32");
```

5. Modify the in_memory attribute of the table

```sql
ALTER TABLE example_db.my_table set ("in_memory" = "true");
```

6. Enable batch delete function

```sql
ALTER TABLE example_db.my_table ENABLE FEATURE "BATCH_DELETE";
```

7. Enable the function of ensuring the import order according to the value of the sequence column

```sql
ALTER TABLE example_db.my_table ENABLE FEATURE "SEQUENCE_LOAD" WITH PROPERTIES ("function_column.sequence_type" = "Date");
```

8. Change the default number of buckets for the table to 50

```sql
ALTER TABLE example_db.my_table MODIFY DISTRIBUTION DISTRIBUTED BY HASH(k1) BUCKETS 50;
```

9. Modify table comments

```sql
ALTER TABLE example_db.my_table MODIFY COMMENT "new comment";
```

10. Modify column comments

```sql
ALTER TABLE example_db.my_table MODIFY COLUMN k1 COMMENT "k1", MODIFY COLUMN k2 COMMENT "k2";
```

11. Modify the engine type

```sql
ALTER TABLE example_db.mysql_table MODIFY ENGINE TO odbc PROPERTIES("driver" = "MySQL");
```

### Example

1. Modify the bloom filter column of the table

```sql
ALTER TABLE example_db.my_table SET ("bloom_filter_columns"="k1,k2,k3");
```

Can also be incorporated into the schema change operation above (note that the syntax for multiple clauses is slightly different)

```sql
ALTER TABLE example_db.my_table
DROP COLUMN col2
PROPERTIES ("bloom_filter_columns"="k1,k2,k3");
```

2. Modify the Colocate property of the table

```sql
ALTER TABLE example_db.my_table set ("colocate_with" = "t1");
```

3. Change the bucketing method of the table from Hash Distribution to Random Distribution

```sql
ALTER TABLE example_db.my_table set ("distribution_type" = "random");
```

4. Modify the dynamic partition attribute of the table (support adding dynamic partition attribute to the table without dynamic partition attribute)

```sql
ALTER TABLE example_db.my_table set ("dynamic_partition.enable" = "false");
```

If you need to add dynamic partition attributes to tables without dynamic partition attributes, you need to specify all dynamic partition attributes
   (Note: adding dynamic partition attributes is not supported for non-partitioned tables)

```sql
ALTER TABLE example_db.my_table set ("dynamic_partition.enable" = "true", "dynamic_partition.time_unit" = "DAY", "dynamic_partition.end" = "3", "dynamic_partition.prefix" = "p", "dynamic_partition. buckets" = "32");
```

5. Modify the in_memory attribute of the table

```sql
ALTER TABLE example_db.my_table set ("in_memory" = "true");
```

6. Enable batch delete function

```sql
ALTER TABLE example_db.my_table ENABLE FEATURE "BATCH_DELETE";
```

7. Enable the function of ensuring the import order according to the value of the sequence column

```sql
ALTER TABLE example_db.my_table ENABLE FEATURE "SEQUENCE_LOAD" WITH PROPERTIES ("function_column.sequence_type" = "Date");
```

8. Change the default number of buckets for the table to 50

```sql
ALTER TABLE example_db.my_table MODIFY DISTRIBUTION DISTRIBUTED BY HASH(k1) BUCKETS 50;
```

9. Modify table comments

```sql
ALTER TABLE example_db.my_table MODIFY COMMENT "new comment";
```

10. Modify column comments

```sql
ALTER TABLE example_db.my_table MODIFY COLUMN k1 COMMENT "k1", MODIFY COLUMN k2 COMMENT "k2";
```

11. Modify the engine type

```sql
ALTER TABLE example_db.mysql_table MODIFY ENGINE TO odbc PROPERTIES("driver" = "MySQL");
```

### Keywords

```text
ALTER, TABLE, PROPERTY
```

### Best Practice