SET CURRENT DECFLOAT ROUNDING MODE

The SET CURRENT DECFLOAT ROUNDING MODE statement changes the value of the CURRENT DECFLOAT ROUNDING MODE special register.

Invocation

This statement can be embedded in an application program or issued interactively. It is an executable statement that can be dynamically prepared.

Authorization

Start of change If a global variable is referenced in the statement, the privileges held by the authorization ID of the statement must include at least one of the following:End of change

Start of change
  • For the global variable identified in the statement,
    • The READ privilege on the global variable, and
    • The system authority *EXECUTE on the library containing the global variable
  • Administrative authority
End of change

Syntax

Read syntax diagramSkip visual syntax diagram
                                       .- = -.   
>>-SET CURRENT DECFLOAT ROUNDING MODE--+-----+------------------>

>----+-ROUND_CEILING---+---------------------------------------><
     +-ROUND_DOWN------+     
     +-ROUND_FLOOR-----+     
     +-ROUND_HALF_DOWN-+     
     +-ROUND_HALF_EVEN-+     
     +-ROUND_HALF_UP---+     
     +-ROUND_UP--------+     
     +-variable--------+     
     '-string-constant-'     

Description

ROUND_CEILING
Round toward +Infinity. If all of the discarded digits are zero or if the sign is negative, the result is unchanged other than the removal of discarded digits. Otherwise, the result coefficient is incremented by one (rounded up).
ROUND_DOWN
Round toward zero (truncation). The discarded digits are ignored.
ROUND_FLOOR
Round toward -Infinity. If all of the discarded digits are zero or if the sign is positive, the result is unchanged other than the removal of the discarded digits. Otherwise, the sign is negative and the result coefficient is incremented by one.
ROUND_HALF_DOWN
Round to nearest; if equidistant, round down. If the discarded digits represent greater than half (0.5) of the value of a one in the next left position, then the result coefficient is incremented by one (rounded up). Otherwise, the discarded digits are ignored.

This rounding mode is not recommended when creating a portable application since it is not supported by the IEEE draft standard for floating-point arithmetic.

ROUND_HALF_EVEN
Round to nearest; if equidistant, round so that the final digit is even. If the discarded digits represent greater than half (0.5) of the value of a one in the next left position, then the result coefficient is incremented by one (rounded up). If they represent less than half, then the result coefficient is not adjusted (that is, the discarded digits are ignored). Otherwise (they represent exactly half), the result coefficient is unaltered if its rightmost digit is even or incremented by one (rounded up) if its rightmost digit is odd (to make an even digit).
ROUND_HALF_UP
Round to nearest; if equidistant, round up. If the discarded digits represent greater than or equal to half (0.5) of the value of a one in the next left position, then the result coefficient is incremented by one (rounded up). Otherwise, the discarded digits are ignored.
ROUND_UP
Round away from zero. If all of the discarded digits are zero, the result is unchanged other than the removal of discarded digits. Otherwise, the result coefficient is incremented by one (rounded up).

This rounding mode is not recommended when creating a portable application since it is not supported by the IEEE draft standard for floating-point arithmetic.

string-constant
A character constant that contains a specification of the rounding mode.
variable
Specifies a variable which contains the value for the CURRENT DECFLOAT ROUNDING MODE. The content is not folded to uppercase.

The variable:

  • Must be a character-string or Unicode graphic-string variable.
  • Must not be followed by an indicator variable.
  • Must contain one of the seven rounding mode keywords.
  • Must be padded on the right with blanks if the variable is fixed length.

Notes

Transaction considerations: The SET CURRENT DECFLOAT ROUNDING MODE statement is not a committable operation. ROLLBACK has no effect on the CURRENT DECFLOAT ROUNDING MODE.

Initial CURRENT DECFLOAT ROUNDING MODE: The initial value of CURRENT DECFLOAT ROUNDING MODE in an activation group is established by the first SQL statement that is executed in the activation group.
  • If the first SQL statement in an activation group is executed from an SQL program or SQL package, the CURRENT DECFLOAT ROUNDING MODE special register is set to the value of the DECFLTRND parameter.
  • Otherwise, the initial value is ROUND_HALF_EVEN.

CURRENT DECFLOAT ROUNDING MODE scope is activation group.

Examples

Example 1: Set the CURRENT DECFLOAT ROUNDING MODE special register to ROUND_DOWN using a string constant and using a keyword.

  SET CURRENT DECFLOAT ROUNDING MODE = 'ROUND_DOWN'
  SET CURRENT DECFLOAT ROUNDING MODE = ROUND_DOWN
Parent topic: Statements