Question Re: ADS Data Dictionary performance issues in Technology Q&A

ADS Data Dictionary performance issues

Former Member — Wed, 18 Jan 2017 10:15:26 GMT

We recently updated our program to use Data Dictionary bound tables instead of free tables. But it seems like our program got a lot slower in Data Dictionary mode than in Free Table mode. Is this because of the encryption added to the Data Dictionary files, or are Data Dictionaries just a lot slower?

Re: ADS Data Dictionary performance issues

jhoehne — Thu, 19 Jan 2017 08:12:31 GMT

Using a DD makes no difference in performance. But encryption is expensive, it slows everything down.

Re: ADS Data Dictionary performance issues

Former Member — Tue, 24 Jan 2017 15:11:45 GMT

I tried disabling encryption and it helped to improve the performance a little.

The AdsSettings we had before Data Dictionary are :

_ADSSettings.NumCachedCursors := 127;
_ADSSettings.NumCachedTables := 127;
_ADSSettings.ShowDeleted := false;

But since we use .adt tables and not DBF I guess ShowDeleted is no longer usefull?
Are there optimal settings for NumCachedCursors / NumCachedTables or is it just trial and error?

Re: ADS Data Dictionary performance issues

jhoehne — Tue, 24 Jan 2017 18:52:52 GMT

I think its try&error, as this depends on your type of database actions, e.g. whether you do ISAM style table navigating or sql style complex queries with multiple joins etc.

Re: ADS Data Dictionary performance issues

jhoehne — Tue, 24 Jan 2017 19:24:25 GMT

I also recommend looking in forums other than this community, e.g. stack overflow. If you're german speaking, maybe the "inoffizielles deutsches Xbase-Forum" is suitable, as they have a ADS sub forum. As it seems you're using Delphi, I strongly recommend the "Delphi Praxis". In both forums the well-known "ADS Guru" Joachim Dürr is more or less active (but definitively more active than here).