Date   Date Overview When to Use Constant Form Native Data Type Examples

Date Overview

The Date native type is a container, which may hold a Date and Time of Day. Analytic Information Server supports Dates in the range of 10¹⁵BC to 10¹⁵AD. This range exceeds the approximate current age of the universe by a factor of 1000. At the extreme ends of the Date range (10¹⁵BC or 10¹⁵AD), Time of Day can be accurately recorded in Days only. At the center of the date range (10⁴BC or 10⁴AD) Time of Day can be accurately recorded in microseconds.

Using the date value, you can perform calendar math and display dates in many different formats. Some date functions require you to enter arguments as date values; others require that date arguments be specified in text form.

When to Use

The Date native type is used to save Date or Time of Day values

Constant Form

Date constants are written as #Month,Day,Year . The # symbol is mandatory; each date component is separated by a comma and no spaces are allowed.

#Dec,12,1993 #Jan,13,56BC #Feb,28,1994 #Jun,15,1876 #Jul,14,1786:6:10:30

The valid month abbreviations are: Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, and Dec. The day must be valid for the specified month. The spelling of the months are case-sensitive. The year must contain all of its digits. If the year is before Christ, it must be followed by the initials BC.

An alternate form allows period symbols instead of commas as in #Month.Day.Year.

#Dec.12.1993 #Jan.13.56BC #Feb.28.1994 #Jun.15.1876 #Jul.14.1786:6:10:30

Native Data Type

The Boolean Data Type is an example of an AIS Native Data Type.

Analytic Information Server stores all of its Native Data Types in Virtual Machine Containers. All containers are stored in memory. Containers provide the basic storage mechanism for modeling data of all types. Containers provide these fundamental characteristics:

Ability to hold any type of data (including code) at any time.

Ability to know what type of data is contained.

Ability to be stored, retrieved and evaluated by the system.

Ability to handle type conversion, and memory management automatically.

Containers come in two sizes, Large and Small. Small containers are six bytes in length, and large containers are ten bytes in length. Large containers can store larger amounts of data immediately and place less of a burden on the Heap manager. Small containers require less immediate space, but place more of a burden on the Heap manager.

Large containers can store the following data types immediately and does not require the services of the Heap manager:

• #void
• error
• Boolean
• Character
• Integer
• Number
• Money
• Percent
• String
• Text
• Character
• ...heap object references...

Small containers can store the following data types immediately without placing additional burden on the Heap manager:

• #void
• error
• Boolean
• Character
• Integer
• Number
• Money
• Percent
• String
• Text
• Character
• ...heap object references...

Analytic Information Server containers can be saved and loaded to and from persistent (database) storage at any time. Containers with immediate data are saved on disk in fixed length records equal to the size of the container. Containers with Heap object references are saved in fixed length records, which are automatically expanded to include the contents of the Heap object, and any objects referenced by the Heap object, etc. This feature is called Object Closure Management and is automatic with every Analytic Information Server container database save. Analytic Information Server containers may be loaded from any database repository record at any time. If the data in the record is immediate, the database load fills the container with the immediate data. If the data in the record is an object closure, the database load fills the container with a Heap object reference, and all of the objects in the record are loaded back into the Heap with the same referential relationships they had when they were saved.

The Date object can be demonstrated by the following examples.