Re: ADO results set vs. BDE


"hajo" <hajospuunup@xxxxxxxxx> ÓÏÏÂÝÉÌ/ÓÏÏÂÝÉÌÁ × ÎÏ×ÏÓÔÑÈ ÓÌÅÄÕÀÝÅÅ:
news:4811e9ea$1@xxxxxxxxxxxxxxxxxxxxxxxxx

"Bill Todd [TeamB]" <no@xxxxxx> wrote:
What is the problem you are trying to solve? In other words, why is
using a client side cursor and fetching the entire result set a problem?

It is difficult to suggest a solution without knowing exactly what
problem you are trying to solve.

--
Bill Todd (TeamB)

Well, the problem really is that our users are used to being able to
perform a query that returns a large result set, but without having to
wait around for all the results to be loaded. With the BDE, you could
fetch a large results set a few records at a time. You wouldn't have to
wait for all the results to be fetched first, which might take some time
if there were a lot of results.

With ADO it seems that the entire result set must be fetched in one go,
which could take a long time.

I know it would be preferable if we didn't fetch large result sets in the
first place, but the BDE's behaviour was quite handy - e.g. if you
accidentally did a wildcard search that pulled back a lot of results, you
wouldn't have to wait. It would be great if this can be done in ADO too.

If BDE had been working fine for those queries, it probably mean that they
are rather simple, which mean that most probably ADO server side
bidirectional cursors will be available for them also.

Another option would be to use TClientDataSet + TDataSetProvider +
TADODataSet with readonly forwardonly server side cursor. In such
combination you could control fetching more precisely. Please note that it
is highly recommended to have separate ADO Connection for each TADODataSet
configured this way.


.

Relevant Pages

  • Re: ADO results set vs. BDE
    ... using a client side cursor and fetching the entire result set a problem? ... With ADO it seems that the entire result set must be fetched in one go, which could take a long time. ...
    (borland.public.delphi.database.ado)
  • Re: Returning Null value instead of contents of field
    ... > When I use a Forward only cursor in SQL Server I can only read the ... I liked the original brown-covered "ADO Examples and Best Practices" which I ... I have noticed that Microsoft over the years ... You can also read up on various providers in OLE DB documentation but it is ...
    (microsoft.public.data.ado)
  • Re: Query performance MS-Access vs. SQL-server 2000
    ... > between the two alternatives is the use of DAO vs ADO: ... This may be due to the cursor type/location you chose to use in ADO. ... which was designed to work directly with Jet databases. ...
    (microsoft.public.sqlserver.programming)
  • Re: Returning Null value instead of contents of field
    ... The code with Forward only cursor works fine with a DB2 varchar ... Microsofts MSDN site on ADO. ... I have noticed that Microsoft over the years ... very quietly updated the documentation. ...
    (microsoft.public.data.ado)
  • Re: ADODB RECORDSET Optimierung
    ... Recordset mit einem Static Cursor öffnest? ... Damit zwingst Du ADO die ganze Tabelle in den Speicher einzulesen und eine Kopie aller Records anzulegen. ...
    (microsoft.public.de.access.clientserver)