C#: Threading Issue while database bulkinsert?
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I have 25 threads running. And each thread does following:

1) reads a txt file with around 1000 records, 
2) put into datatable
3) sql bulkinsert into sql server

After starting all the threads, I need to wait for the threads to complete processing and for this I have used Thread.Join. My issue is, the threads finishes completetion task even before they have finished with the above steps. Only reason I can see here is that, the database table gradually increases size to more that 20 million records. And there on, it takes some time to insert data. Is it that the thread gets aborted while waiting to insert data to Sql Server? I have even tried using Task.Factory.StartNew and ContinueWhenAll, but resiult is same. Is there any better way of handling this?

Thanks in advance

Anshuman