With “issues” I mean rather I am in sort of the same situation. Firstly, I am 
not always 100% sure how to read and interpret the query plan. I basically try 
to eliminate NATURAL (full table scan) in any query. I also try to check the 
number of indexed and non- indexed reads. But when there is something wrong I 
am not always sure where to look and how to use the query plan to remedy the 
situation.  Also, when checking the query execution, it seems that my indexes 
stats are not good and I am not sure how to remedy this. 

 

I don’t want to hijack Zoran’s thread and will post my own in due course.

 

Thanks for the response Set

 

Louis

 

 

From: firebird-support@yahoogroups.com 
[mailto:firebird-support@yahoogroups.com] 
Sent: 09 February 2015 12:00 PM
To: firebird-support@yahoogroups.com
Subject: RE: [firebird-support] Re: Speed issues

 

  

>I am having similar issues. Are there any resources to read up on this? 

What do you mean by "similar issues", Louis? Zoran first showed us his SQL and 
plan, so that we more or less could see that his SQL, plan and indexes seemed 
good (that's arguably the most common reason for speed problems). Unfortunately 
I don't know of any generally good resources for fixing speed issues with 
Firebird (excepting this list and sometimes firebird-devel, possibly The 
Firebird book by Helen Borrie can have some tips as well, I don't know), and I 
doubt there exist any good resources focusing particularly on speed problems 
with big tables (whereas I cannot rule out there could exist some good 
resources for more general speed problems). 

I never answered Zorans question since I've no experience with tables with more 
than 100 million rows and Seans answers seemed sensible. I noticed two things 
that they haven't discussed (but that I don't know how relevant would be) and 
that is that we haven't seen the DDL of his tables (wondering whether any of 
the tables involved have lots of fields or large CHAR and VARCHAR fields that 
could affect performance) and that we don't know how many rows would be 
returned from the same query if DISTINCT was removed. 

Set 





[Non-text portions of this message have been removed]

    • ... zilez2...@yahoo.com [firebird-support]
  • ... zilez2...@yahoo.com [firebird-support]
    • ... 'Leyne, Sean' s...@broadviewsoftware.com [firebird-support]
      • ... zilez2...@yahoo.com [firebird-support]
        • ... 'Leyne, Sean' s...@broadviewsoftware.com [firebird-support]
          • ... zilez2...@yahoo.com [firebird-support]
            • ... 'Leyne, Sean' s...@broadviewsoftware.com [firebird-support]
            • ... zilez2...@yahoo.com [firebird-support]
            • ... 'Louis van Alphen' lo...@nucleo.co.za [firebird-support]
            • ... Svein Erling Tysvær svein.erling.tysv...@kreftregisteret.no [firebird-support]
            • ... 'Louis van Alphen' lo...@nucleo.co.za [firebird-support]
            • ... zilez2...@yahoo.com [firebird-support]
            • ... zilez2...@yahoo.com [firebird-support]
            • ... 'Leyne, Sean' s...@broadviewsoftware.com [firebird-support]
          • ... zilez2...@yahoo.com [firebird-support]
          • ... zilez2...@yahoo.com [firebird-support]

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