Hi!

I have a BindingSource which has a DataSet as it's datasource. The DataMember property of the
BindingSource is set to a table in the DataSet which contains about 360000 rows. When I set the
Filter property to e.g. "Name LIKE '%a'" it takes about three to five Minutes till the filtering
completes. When using the Select method of the DataTable, it only takes six seconds. I've
already tried things like setting RaiseListChangedEvents to false, calling SuspendBinding(),
but to no avail. It doesn't make a difference whether the BindingSource is databound or not.

Why is this and is there a way to speed up the filtering?

By default, filter is done after all data has been retieved, in the memory. So, if there're millions of records, it'll be very slow and also occupies a lot of memory. You can try to filter at the database level using the where clause. This can improve the performance a lot.

360000 is really a big number, why not query in DataBase and refill the datagrid?

By default, filter is done after all data has been retieved, in the memory. So, if there're millions of records, it'll be very slow and also occupies a lot of memory. You can try to filter at the database level using the where clause. This can improve the performance a lot.

Because I'd like to avoid another round-trip to the database. The filtering is done immediately after the user presses a key (like "Find as you type" in Firefox) and as the client gets it's data over the an Internet, I'd like to avoid transferring the whole data each time the user applies a filter. DataTable.Select() only needs about six seconds to retrieve the data, which would be perfectly fine, but I thought there would be a way to avoid writing additional code for that.