MongoDB. Index was out of range

Question

I keep having this error as I try to retrieve thousands of documents from the collection.

index was out of range. must be non-negative and less than the size of the collection. parameter : Index

Here is my code as I query the documents:

        MongoCollection<Book> collection = PDatabase.GetCollection<Book>("books");
        List<IProduct> products = new List<IProduct>();
        var books = collection.Find(Query.GT("stock", 0)).SetFlags(QueryFlags.NoCursorTimeout);
        foreach (var book in books)
        {
            try
            {
                products.Add(book);
            }
            catch (Exception ex) { Console.WriteLine(ex.Message);  }
        }
        return products;

As I looked at the exception message, it says "index was out of range. must be non-negative and less than the size of the collection. Parameter : Index"

I have a 'Book' class which i used as I initialize MongoCollection. So .find will return a list of 'Book'. And 'Book' implements my 'IProduct' interface — Wylan Osorio, Jun 17 '15 at 19:03
`PDatabase.GetCollection("books")` retuns anything?obviously `products` is not valid in the context — Amit Kumar Ghosh, Jun 17 '15 at 19:05
I editted it. Its 'books' where each book added to the Iproduct list. — Wylan Osorio, Jun 17 '15 at 19:09
each iteration of the books as when it goes to catch I actually see the current book having values. So its not null. — Wylan Osorio, Jun 17 '15 at 19:19
Instead of printing the ex.Message, just print "ex". It will include the stacktrace. It'll point to where the exception is coming from. Please update description with that information as well. — Craig Wilson, Jun 17 '15 at 19:23
The main error is "An error occurred while deserializing the "property" property of class ''class": Exception of type 'System.OutOfMemoryException' was thrown". Its because of the huge number of documents queried. I tried limiting the query (eg: .SetLimit(100) ) and it works. I wonder how to deal with this huge documents that I need. — Wylan Osorio, Jun 18 '15 at 13:54

score 0 · Accepted Answer · edited May 23 '17 at 12:02

0

You mention in the comments that the underlying issue is an OutOfMemoryException.

Answer here suggests paging best practices MongoDB - paging

edited May 23 '17 at 12:02

Community

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answered Jun 18 '15 at 15:38

obaylis

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I dont use paging. I bet the error is about the size of List which is millions since my documents is more than 6 million. – Wylan Osorio Jun 18 '15 at 16:05
I was suggesting paging may benefit you. What are you hoping to do with 6 million documents anyway? – obaylis Jun 19 '15 at 09:48
Thank you, I solved it using skip and limit. This way not all documents are loaded in one query. – Wylan Osorio Jun 20 '15 at 07:01

MongoDB. Index was out of range

1 Answers1