ALTER BLOCK RULE

Function

This function modifies the attributes of a filtering rule, including the filtering rule name, bound client name, client IP address, user, and matching mode.

This syntax is supported only by clusters of 9.1.0.100 and later versions.

Precautions

• Only a user with the database owner permission or the gs_role_block role permission can run the ALTER BLOCK RULE statement. A system administrator has this permission by default.
• The DEFAULT syntax is used to reset an attribute, but it applies only to optional options.

Syntax

1
2
3
4
5
6
7

ALTER BLOCK RULE block_name
    [ [ TO user_name@'host' ] | [ TO user_name ] | [ TO 'host' ] | [ TO DEFAULT ] ] |
    [ FOR UPDATE | SELECT | INSERT | DELETE | MERGE | DEFAULT ] |
    FILTER BY
    { SQL ( 'text' ) | TEMPLATE ( template_parameter = value ) }
    [ WITH ( { with_parameter = value }, [, ... ] ) ];
ALTER BLOCK RULE block_name RENAME to new_block_name;

Parameter Description

• block_name

  Name of the query filtering rule whose attributes need to be modified.

  Value range: a string. It must comply with the naming convention.

• user_name

  Queries the users to which the filtering rule applies.

  Value range: A string. It must be a valid username.

• host

  Queries the client IP address to which the filtering rule applies.

  Value range: a string of valid IP addresses.

• SQL

  Queries the regular expression matching statement of the filtering rule.

  Value range: a string or a regular expression.

• template_parameter

  Queries a filtering rule matching template.

  Value range: unique_sql_id/sql_hash. The value is a character string, where unique_sql_id must be all digits.

• with_parameter

  Queries filtering rule options.

  Valid value:

  • application_name: client name.
  • query_band
  • table_num: number of tables scanned by the statement.
  • partition_num: maximum number of partitions to be scanned by the operator.
  • estimate_row: estimated maximum number of table rows scanned by the operator.
  • resource_pool: name of the resource pool to be switched to.
  • max_active_num: maximum number of concurrent statements corresponding to the rule.
  • is_warning: whether an alarm should be generated or an error should be reported when a statement is intercepted.

Examples

Create a query rule query_block.

1

CREATE BLOCK RULE query_block FILTER BY SQL('update table_table set a=1');

Modify the attributes of the query rule query_block.

1

ALTER BLOCK RULE query_block TO user1@'192.168.x.x' FOR SELECT FILTER BY SQL('select * from table_name')WITH(application_name='gsql',query_band='test1',table_num='2',partition_num='3',estimate_row='1000',resource_pool='rsp1',max_active_num='3',is_warning='off');

Rename the query rule query_block.

1

ALTER BLOCK RULE query_block RENAME TO query_block_new;