Re: Aggregate performance issue

2012-03-17 Thread Thomas Mueller
Hi, > Any thoughts on why the group sorted has a poorer performance? No. > Is there a way to override the choices? No, currently not. Regards, Thomas -- You received this message because you are subscribed to the Google Groups "H2 Database" group. To post to this group, send email to h2-dat

Re: Aggregate performance issue

2012-02-23 Thread Loic Petit
Hi Thomas, Thanks for the answer (I didnt see it at first). I'm just testing every possible query plans for a study and I have also an accumulated buffer that can do the trick as well. Any thoughts on why the group sorted has a poorer performance? Is there a way to override the choices? Thanks L

Re: Aggregate performance issue

2012-02-16 Thread Thomas Mueller
Hi, Large result sets are buffered on disk (in a temporary table or temporary file). What you could do is create a separate table where you keep the sum of the value, plus the count, grouped by id. The table would need to be updated using a trigger. That way, you don't need to read all rows every

Aggregate performance issue

2012-02-14 Thread Loic Petit
Hi, I'm currently experimenting performance issues with the aggregate operation. Here is my data : A historic of values for different ids CREATE TABLE Bench (id INT NOT NULL, value INT NOT NULL, T TIMESTAMP NOT NULL) Thereafter I insert a lot of data in it (generated). My parameter for generatio