here is the trace log
2012/7/27 Stefan Manegold
Hi,
does without substring() also mean without group by? (Since you group on the substring())
In other words, what is the exact query you run without substring that takes 1-3 seconds?
And: Could you run both queries prefixed with TRACE and share the profiling output?
Stefan
On Fri, Jul 27, 2012 at 08:41:43AM +0800, li, xiaohua wrote:
Hi all: we are testing monetdb on a sql
select substring(fact_bk,1,1) as aa,sum(1) as recordcount from f_activity group by aa the table f_activity have about 5 million rows. when i run this sql, monetdb need about 30 seconds . (if we use another no calculated column, it need only 1-3 seconds) when I run this sql on sql server, it needs only 7 seconds.
is monetdb not good at calculated column? or we have made some mistake?
please tell me the reason, thank you.
lixiaohua Shanghai,China
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