I am totally new to ArcGis' Model Builder, and I need some advice as how to build an OD cost matrix for large sets of origins and destinations.
I want to compute an OD matrix where I can have as many as 20,000 points as origins and as destinations. Using the normal procedure with Network Analyst results in an "out of memory error". That's why I turned to model builder.
I managed to (re-)build the core model that computes the distance between OD pairs with the network dataset (niger_ND) and the points (p100). The output is written in the database reseau.mdb. This works fine.
Now, I want to add some features to my model, but I do not know exactly where I should put them:
- Each point in the layer containing the points has a unique identifier. As origins, I want to select only 1000 of them at a time. When the analysis is done, I want to relaunch the process on the next 1000 points until every point has been used. How should I design the model to use my points one batch at a time?
- With each batch of origins, I save the result in a database. How can I avoid overwriting the previous result by giving a different name to the output at each iteration?
I guess it is not too complicated when you know Model Builder, but I do not fully understand its logic yet.
Thanks for your help!