predicate
A predicate is a comparison of a single column value to a constant or list of constants.
The column name identifies a column of the named table that is used in the comparison. You can specify the following comparison operators:
Operator | Meaning |
|---|---|
< | Less than |
< = | Less than or equal |
< > | Not equal |
= | Equal |
¬ = | Not equal |
> = | Greater than or equal |
> | Greater than |
IN | Equal to any |
NOT IN | Not equal to all |
constant
The constant specifies a value to be compared to the column value. REORG PLUS then evaluates the result based on the preceding relative operator. Observe the rules for constants in the following table. For the comparison, the associated constant must match the data type of the column (that is, numeric to numeric, string to string, and date/time to date/time).
You should avoid nonstandard comparisons. For more information, see rules for constants in the IBM Db2 SQL Reference.
If you specify a list of constants, you can improve performance by specifying the constants in ascending sequential order. When you specify the list in this order, you save processing time because REORG PLUS does not sort the list.
Type of constant | Additional details |
|---|---|
Integer | Identical to Db2 SQL integer constants The constant must be within the range of the column’s data type. |
Decimal | Identical to Db2 SQL decimal constants The constant must be within the range of the column’s data type. |
Character string | Identical to Db2 SQL strings Use ' ' to denote an empty string. |
Hexadecimal strings | Identical to Db2 SQL hexadecimal strings, except that string length is limited to 256 bytes |
Graphic string | Limited to 256 bytes |
Date/time string | With the following exceptions, identical to Db2 SQL date/time strings Exceptions:
|
Floating point | Not supported |
Decimal floating point | Not supported |
Binary string | Not supported |
LOB | Not supported |
Row ID | Not supported |
NULL
You can specify the keyword NULL as a constant for columns that can be set to null. NULL is generally used with the =, < >, ¬ =, IN, and NOT IN operators, but you can specify it with any of the allowed operators.
The null value is always higher than all other values. To bypass columns that allow nulls, specify AND¬ =NULL.
CURRENT DATE -labeledDuration
The CURRENT DATE option describes the current date or, optionally, describes the current date minus a duration in days, months, or years. The rules for date/time arithmetic using labeled durations are identical to the Db2 SQL rules stated in the IBM Db2 SQL Reference manual. The CURRENT DATE is taken from the local time-of-day clock during the UTILINIT phase.
CURRENT TIMESTAMP WITH TIME ZONE -labeledDuration
The CURRENT TIMESTAMP option describes the current timestamp. Optionally, you can include one of the following specifications with CURRENT TIMESTAMP:
- WITH TIME ZONE to include the time zone (from the IMPLICIT_TZ option, described in IMPLICIT_TZ) in the timestamp
- A duration (preceded by a minus sign) in days, months, or years, which results in the current timestamp minus that duration. The rules for date/time arithmetic using labeled durations are identical to the Db2 SQL rules stated in the IBM Db2 SQL Reference manual.
The CURRENT TIMESTAMP is taken from the local time-of-day clock during the UTILINIT phase.