In the SqlCE Library, it's a mechanism that you can retrieve data a lot
faster than doing a regular Select statmenent with a WHERE Clause. Remember
though, while TableDirect is available w/ other providers, what I'm speaking
about here is specifically about CE.
Basically, you create a new command and specify the tablename
SqlCeCommand cmd = new SqlCeCommand("MyTableName", connection);
Next, specify the index
cmd.IndexName = "WhateverMyIndexNameIs";
Next, set the range...
cmd.SetRange(DbRangeOptions.InclusiveStart|DbRangeOptions.InclusiveEnd,
beginningValue, endingValue);
now, you execute your reader...
But instead of while(Reader.Read())
Use, Reader.Seek(DbSeekOptions.AfterEqual, firstvalue, secondValue) where
firstvalue and secondvalue correspond to the range you wanted to search on
in the index.
It's a faster way to grab data but from what I've seen, very very little
documentation on it. There is some stuff in BOL for Sql CE though.
Let me know if you have any furhter questions.