Adapter for Oracle: Support for System-Versioned Temporal Tables

Temporal queries against Oracle System-Versioned tables have been implemented by introducing fields with TEMPORAL_PROPERTY SYSTEMTIME. Such a field is added by editing the synonym for the table. For example:

DEFINE FIELD1/HYYMDm WITH REALFLD TEMPORAL_PROPERTY SYSTEMTIME = ;$

The following are requirements for the field with TEMPORAL_PROPERTY SYSTEMTIME.

• The field can have any valid field name.
• The datatype must be a date-time datatype with sufficient precision.
• The WITH clause is required and must reference a real table column.

Fields with TEMPORAL_PROPERTY=SYSTEMTIME can only be used in a single WHERE test of one of the following two types.

• WHERE field EQ expression

  This type of WHERE test translates to an ORACLE AS OF TIMESTAMP clause.

• WHERE field FROM expression1 TO expression2

  This type of WHERE test translates to a VERSIONS BETWEEN TIMESTAMP clause.

where:

expression, expression1, expression2

Must be date-time expressions or constants. When used in a FROM-TO expression, the constants DT('0001-01-01') and DT('9999-12-31') represent the oldest and most recent applicable timestamps. They translate to the ORACLE keywords MINVALUE and MAXVALUE.