Willian,

Is always nice to see messages like yours, they tell you that DataSets are
slow, however most the alternatives are less quick.

Therefore ask the one who said this to you about an alternative and ask him
a guarantee that it is quicker.

Some people use a dataset to make a copy of all the data in memory, then
they don't succeed and show their failures by saying things like you have
heard and go back to the old simulating punch card systems on disk they were
used to.

About the memory, be aware that OOP programming is not anymore using
principles of 1980, it is for sure spending more memory. Although the
assemblies (Exe/DLL) are extremely small compared to programs made by
languages from before the time of Net.

Cor

A Dataset is simply a collection of DataTable objects. The DataTable has
evolved to be fairly efficient and provides a whole series of properties,
methods and events that can reduce the code you have to write (fairly
dramatically). Yes, you can load up a custom array with rows from a query
but this means writing a lot more code that you have to support. Yes, you
bind to any class that supports IBindingList including arrays and
collections. Memory is never a consideration if you are judicious in how you
execute the query. No, a query should not be executed to return all the rows
of a database table. I discuss this in detail in my book.