Guys, I've been astonished by the help I've received with this problem - thank you very much everyone. I'm afraid to say that the problem was as stupid as me consuming the exception on a particular record. Best practice point to self, and I'm really sorry for wasting peoples time on such a simple thing. I normally go out of my way to Google for problems, but since 726301 is not a magic number/ceiling (as it was just an exception) I was really scratching my head over this one without seeing the obvious. Anyway, thanks again for everyone's time, and for the suggestions. Ben

Hi Jon, Thanks for your reply, and the suggestions. Could I point you to my reply to Luc for a discussion of this out-of-memory limitation? And, I have been very careful to limit the number of fields I use and don't have any string columns, so although I take your point that 8 million rows is a beast, in SQL management studio the size of comma delimited output file is less than 1.5gig - I've got a 32 bit machine with maximum memory so I am skating on thin ice, but still I expected it to work out memory wise. I'll look into LAPACK - thanks for the suggestion. Ben

Hi Luc, Thanks for your reply. In answer to your questions: I don't get an exception - it just terminates the while(Reader.Read()) loop at 7263001 records. I have actually slightly increased the field count of the query (which makes it also take much longer) - but this doesn't affect the number of records it tops out at, which made me think that timeout and oom might not be the reason. I used a sp in order to be able to test and maintain the query on the server rather than just having a long text string select statement in my C# code. Cheers, Ben

Hi there, I am reading a (rather large) MS-SQL stored procedure into C# using the SqlDataReader. I expect this to return slightly over 8,000,000 records, but it consistently maxes out at 726,301. I cannot for the life in me see why - when running the stored procedure (which has no input parameters) in SQL Server Management Studio it returns the correct number of records. I am running VS 2008 Professional with SQL Server 2008 Developer Ed. The code is paraphrased as follows: // Set up a list of data type Record (my own) to hold the output of the sp List records = new List(); System.Data.SqlClient.SqlConnection Connection = new System.Data.SqlClient.SqlConnection(ConnectionString); System.Data.SqlClient.SqlCommand Command; try { Connection.Open(); { Command = new System.Data.SqlClient.SqlCommand("StoredProcedure", Connection); Command.CommandType = CommandType.StoredProcedure; System.Data.SqlClient.SqlDataReader Reader = Command.ExecuteReader(); while (Reader.Read()) { Record NewRecord = new Record(); NewRecord.PAR1 = Reader.GetInt32(Reader.GetOrdinal("PAR1")); NewRecord.PAR2 = Reader.GetInt32(Reader.GetOrdinal("PAR2"));... etc records.Add(NewRecord); } } } catch { } finally { Connection.Close(); } Thanks a million for any help! Ben