The rapid grouping facility can be used when an SQL that satisfies all the following conditions is executed:

• HiRDB/Parallel Server
  
  • The GROUP BY clause is specified.
  • Use of the rapid grouping facility is defined in the system common definitions, front-end server definitions, client environment definitions, or routine definitions.
  • The selection expression column length is 4,096 or less.
  • The grouping process is not for an inquiry specification that becomes the input for a set operation (UNION, EXCEPT).
  • DISTINCT is not specified within the set function.
  • A character string-type column with a defined length of 256 bytes or more, a BINARY-type column, or a BLOB-type column is not specified in the set function.
  • When a HAVING clause is specified in the specification of a query in which the GROUP BY clause is specified, no subquery is specified in the HAVING clause.
  • No subquery is specified in the selection expression.
  In the following case, rapid grouping is performed regardless of whether or not the SQL optimization option is specified:
  
  • Grouping can be executed without sorting, using a grouping column index.
  The following facilities cannot be used when the rapid grouping facility is used:
  
  • Facility for creating multiple objects
  • AND multi-index use (however, this function is used with structured repetition predicates and functions dedicated to index type plug-ins).
• HiRDB/Single Server
  
  • The GROUP BY clause is specified.
  • Use of the rapid grouping facility is defined in the system common definitions, client environment definitions, or routine definitions.
  • The grouping process is not for an inquiry specification that becomes the input for a set operation (UNION, EXCEPT).
  • DISTINCT is not specified within the set function.
  • A character string-type column with a defined length of 256 bytes or more, a BINARY-type column, or a BLOB-type column is not specified in the set function.
  In the following case, rapid grouping is performed regardless of whether or not the SQL optimization option is specified:
  
  • Grouping can be executed without sorting, using a grouping column index or by sorting join columns for sort/merge join.
  The following facility is not used when the rapid grouping facility is used:
  
  • AND multi-index use (however, this function is used with structured repetition predicates and functions dedicated to index type plug-ins).