[fpc-pascal] sqldb how to find a record fast with primary key

[Felipe Monteiro de Carvalho]

On Fri, Oct 21, 2011 at 5:22 PM, Ludo Brands <ludo.brands at free.fr> wrote:
> You can use indices and locate with TSQLQuery as follows:
>  SQLQuery1.AddIndex('idx_no_art','no_art',[]);
>  SQLQuery1.IndexName:='idx_no_art';
>  SQLQuery1.Open;
>  ...
>  SQLQuery1.Locate('no_art','200295',[]);

Thanks, that's really interresting, but it does not seam to be useful
in my case. Basically my application is a cgi app which receives a
request, does some modifications in the database and then sends back
some other data based on the request and on the database and then it
just quits.

I get the value of the primary key of the table from the request, so I
though that because it is the primary key I would be able to quickly
jump to it. But it seams that not? From what I understood the
solutions are first going through the entire table and indexing it to
make future lookups faster. But this does not seam to use the fact
that my field is the primary key.

>From my experience doing a loop

while not SQLQuery.EOF do
  compare
  SQLQuery.Next

is *really* slow.

But I doubt that first indexing the whole table and then looking up
the value 1 time will be any faster.

I am thinking of moving to FastCGI, but I'm not sure if then I would
be able to index the table and gain speed in future requests. maybe...

-- 
Felipe Monteiro de Carvalho