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List of SQL Functions

Johannes Küpper edited this page Jun 11, 2013 · 12 revisions

Basic Functions

Casts and Constructors

Creating posttime-objects.

  • posttime - This function allows casts from various types.
  • posttime_in - Input function for the PostTIME-type (c.f. the PostgreSQL-documentation).

ISO19108 Functions

The following functions are taken over from ISO19108 - for that reason these are only defined for the primitive object types. However, if you call one of these with a multi object you will get 'NAP' if the return type is text or '-1' if the return type is numeric. That means you can call these functions with any PostTIME instance without causing an error.

Boolean functions

Determine if some assumption about an instance's state is true or false.

Accessing Functions

Returning information about a distinct point of interest.

  • pt_centroid - Calculate the instant that is the middle of the object's temporal bounding box.
  • pt_refsys_instance - Returning the instance-number of a PostTIME's reference system.
  • pt_refsys_type - Query the type of an instance's reference system.
  • pt_temporal_bbox - Determine the covered period of time for one or more objects.
  • pt_type - Getting the type of an instance.
  • pt_weekday_int - Returns the weekday of an instant.

Transforming Functions

Changes an object and returns the new instance or instances.

Spatio-temporal Functions

Utilizing PostTIME as well as PostGIS.

  • pt_predecessor - True if one geometry-time tuple is the predecessor of another.
  • pt_successor - Antagonist of pt_predecessor.
  • pt_spatiotemporal_statistics - Counting the occurrence of some event-objects relative to a static reference geometry in customizable temporal histogram-intervals.