At first I would thanks anyone for answering me.

The first mistake I did is to think that an TIB_Cursor or an TIB_Query
must use as connection only a TIB_Database and not a TIBODatabase.
Now I know that I can use a TIBODatabase as connection both for
TIBOQuery both for TIB_ components.

I think that the component that made my applycation slow are the same
that i can substitute with TIB_ components because they don't use
datasource component.

I would like to explain what i do in my applycation.
I create some components in Delphi that made the development of my
application faster because they encapsulate many routine as decoding the
name of a customer or linking a customer field with the form that manage
the customer archives.
I create many of this components but all of this have an property that is
the object to use in order to extract information from the database; this
object are used only to retrieve information, they never made change.

An example:
My customer table are something like this:
CUSTOMER_TABLE ( CUST_CODE CHAR(10), CUST_NAME CHAR(40)...
... , CUST_AGENT CHAR(3), CUST_TAB1 CHAR(3), CUST_TAB2 CHAR(3)...
and so on.

In the application that manage the customer table, every field is associated
with a my personal component and every time I locate a customer in the
table, the component in automatic refresh the description of every
associated
field (for ex. the name of the agent) (the table can have 20/30 field to
decode).
To all that components I associate ever the same TIBOQuery, that
have no persistent fields, and every type of components set the TIBOQuery
Sql statement as its need (ex. in order to decode the agent the select
statement
is SELECT DESAGENTE FROM AGENT_TABLE WHERE
AGENT_CODE = 'XXX').
(that statement can be very different, i not only decode the field but i use
the TIBOQuery to find information about the validity of the field value
and a lot of more funtionality)

Now, at first I will try to change, were possible, the TIBOQuery with
the TIB_Cursor and I see what happen.

If you have some suggestion or something to say about the usage
I made of the component I apreciate it.

Thank you to all and sorry for my bad english.
Mirko Guidolin