# Cost - Category¶

Warning

Proposed functions for next mayor release.

• They are not officially in the current release.
• They will likely officially be part of the next mayor release:
• The functions make use of ANY-INTEGER and ANY-NUMERICAL
• Name might not change. (But still can)
• Signature might not change. (But still can)
• Functionality might not change. (But still can)
• pgTap tests have being done. But might need more.
• Documentation might need refinement.

## General Information¶

### Characteristics¶

The main Characteristics are:

• Each function works as part of the family it belongs to.
• It does not return a path.
• Returns the sum of the costs of the resulting path(s) for pair combination of nodes in the graph.
• Process is done only on edges with positive costs.
• Values are returned when there is a path.
• The returned values are in the form of a set of (start_vid, end_vid, agg_cost).
• When the starting vertex and ending vertex are the same, there is no path.
• The agg_cost int the non included values (v, v) is 0.
• When the starting vertex and ending vertex are the different and there is no path.
• The agg_cost in the non included values (u, v) is $$\infty$$.
• Let be the case the values returned are stored in a table, so the unique index would be the pair: (start_vid, end_vid).
• Depending on the function and its parameters, the results can be symmetric.
• The agg_cost of (u, v) is the same as for (v, u).
• Any duplicated value in the start_vids or in end_vids are ignored.
• The returned values are ordered:
• start_vid ascending
• end_vid ascending