Examples of Topological sorts in Massive graphs

I am interested in finding some real world massive data sets (>=1M) which needed to be topologically sorted. Perhaps something relating to bioinformatics?

Which example of a graph would be suitable for a topological sort?

So topological sorting can be achieved for only directed and acyclic graphs.

What is topological sort explain with an example?

In topological sorting, we need to print a vertex before its adjacent vertices. For example, in the given graph, the vertex '5' should be printed before vertex '0', but unlike DFS, the vertex '4' should also be printed before vertex '0'. So Topological sorting is different from DFS.

How many topological sorting is possible in a graph?

Number of different topological orderings possible = 6.

What is topological sorting in a graph?

A topological sort is a graph traversal in which each node v is only visited after all of its dependencies have been visited. If the graph contains no directed cycles, then it is a directed acyclic graph.

Did you have a look at the Stanford Large Network Dataset Collection? There are plenty of real world datasets, huge ones too, many of them directed.