Question

Ok, the story so far is i have a datatable, about 10,000 lines or so. and about 150 columns per row. ao more or less 150.000 cells in this datatable. i have all updateing working fine
but the updating is slow.
I need to iterate through a list of porcedures then update cells in the table depending on the procedure. when i am completle finished updating about 75% – 80% of all the cells will have changed.
I am using a search on the table using a primary key index assigened to an INT value.

datatable.rows.find() seems a a little quicker
datatable.select ( expression ) almost the same but little difference.

Is there any ideas who may speed this up. uppon changing 80,000 – 120,000 cells it can take minutes.

anyideas would be great thanks.

Answer 1

A study in the March 2005 issue of ASP.Net Pro magazine compared various approaches involving DataTables, DataViews and DataReaders. Their findings were that the fastest approach depended upon the number of records involved.

For 50 records or less, by far the fastest search method was a For..Next loop on the DataTable's DataRowCollection. That approach was followed by DataRowCollection.Find. Many times slower were re-retrieving the data with a DataReader, using DataView.RowFilter, and worst of all using DataTable.Select.

For 500 – 5,000 records, the fastest search was with DataRowCollection.Find, followed closely by DataTable.Select. The worst by far for this range of records were DataView.RowFilter and DataView.FindRows.

For 50,000 records, the fastest search was accomplished with DataRowCollection.Find. In a close second place was re-retrieving the records with a DataReader. The worst by far for this category were DataView.RowFilter and DataView.FindRows.