Question

I am working at the moment with the advantage database server from sybase. I am programming in delphi and I am using a local server. My problem is, if I make a sql query inside my own source code the query is 3 times slower (especially for nested Select queries) as if I would use exactly the same query inside the Advantage Database Architect delivered by sybase, too.
The database is also the same. Is there any optimization step I am missing?

My Source Code looks like this:

  //Initializing Connection and Query
  FADSConnection.LoginPrompt := false;
  FADSConnection.ConnectPath := Filename;
  FADSConnection.AdsServerTypes := [stADS_LOCAL];
  FADSConnection.Name := 'ADB';
  FADSConnection.EncryptionOptions.DataEncryptionType := etAdsAES256;
  FADSConnection.IsConnected := true;


  FADSQuery.DatabaseName := FADSConnection.Name;
  FADSQuery.SourceTableType := ttAdsADT;
  FADSQuery.AdsTableOptions.AdsCharType := GERMAN_VFP_CI_AS_437;

  s := 'SELECT *' 
       + 'FROM ADB_Table1 WHERE No IN' 
       +'(SELECT No' 
       +       'FROM ADB_Table2 WHERE V=0.4 AND N=26 AND No IN' 
       +       '(SELECT No FROM ADB_Table2 WHERE V=0.6 AND N=8)) AND Count=2'

  FADSQuery.sql.Text := s;
  FADSQuery.Open;
  FADSQuery.first;

The Query takes 600 ms in my program. In the advantage database architect it needs 200 ms. The database has around 18000 entries.

Thank you in advance!

Answer 1

So, I found my mistake:

The Problem is the initialization of the query instance.
Somehow overhanding of the Source Table Type and the AdsCharType isn’t necessary.

FADSQuery.SourceTableType := ttAdsAdt;
FADSQuery.Tableoptions.AdsCharType := GERMAN_VFP_CI_AS_437;

I just removed the above lines and my queries are nearly as fast as the Advantage Data Architect.