Create Hologres Table Groups via HG_CREATE_TABLE_GROUP - Hologres

You can use the HG_CREATE_TABLE_GROUP function to create a table group and specify the shard count for the created table group. This topic describes how to use the HG_CREATE_TABLE_GROUP function in Hologres.

Limits

Only Hologres V0.10 and later allow you to use the HG_CREATE_TABLE_GROUP function.
Only the superusers of an instance and the owners of a database can call the HG_CREATE_TABLE_GROUP function.

Syntax

The HG_CREATE_TABLE_GROUP function that you can use in Hologres uses the following syntax:

CALL HG_CREATE_TABLE_GROUP ( 'table_group_name', shard_count );

The following table describes the parameters in the syntax.

Parameter	Description
table_group_name	The name of the table group.
shard_count	The shard count. The value must be an integer. We recommend that you set this parameter to a value that ranges from 5 to 150. For more information about the recommended values of the shard count, see Instance specifications.

Example

Execute the following statement to create a table group that is named TG10 and whose shard count is 10:

CALL HG_CREATE_TABLE_GROUP( 'TG10', 10 );

Other related statements

Execute the following statements to create a table named tbl and add the table to the table group named TG10:
Note If you do not specify the table group to which the table is to be added, the table is added to the default table group.
```
begin;
create table tbl(colA text, colB text);
call set_table_property('tbl','table_group','TG10');
commit;
```
Execute the following statement to set the table group named TG10 as the default table group of the database:
```
hg_update_database_property('default_table_group','TG10');
```