13
The Time of Day Dimension

The Time of Day dimension provides granularity down to the second at which an event occurred.

This chapter contains the following topics:

• Time of Day Dimension Hierarchies

• Time of Day Dimension Levels

Time of Day Dimension Hierarchies

The Time of Day dimension contains one hierarchy:

• The Time of Day Hierarchy

The sections that follow list the levels in this hierarchy, followed by a diagram that provides a graphical representation.

The Time of Day Hierarchy

This hierarchy contains the following levels, listed from top to bottom. For details about the attributes of each level, see Time of Day Dimension Levels.

• Hour

• Minute

• Second

Figure 13-1 The Time of Day Level Hierarchy

Text description of the illustration time-of-.gif

Time of Day Dimension Levels

The Time of Day dimension is comprised of the following levels. For each level, information about each attribute (column name) is provided in the following format:

• Attribute: Description (example value)

In addition to the pre-defined attributes, the levels contains five "generic" attributes that can be defined by the user.

CLK_L_HOUR

• Hour_Number: Hour number in 24-hour form; natural key. (0, 1, 2, ..., 23)

• Hour_Name: Descriptive name for the hour. (Midnight - 1am, 1am - 2am)

• Hour_Attributes 1-5: Hour level user-defined attributes.

CLK_L_MINUTE

• Minute_Number: Number of seconds since midnight; natural key. (0, 1, 2, ..., 86399)

• Minute_of_Hour: Minute number of the hour. (0, 1, 2, ..., 59)

• Minute_Attributes 1-5: Minute level user-defined attributes.

CLK_L_SECOND

• Second_Number: Status code returned from the Web server; natural key. (200, 201, 302, 404)

• Second_of_Minute: Second number of the minute. (0, 1, 2, ..., 59)

• Second_Attributes 1-5: Second level user-defined attributes.