Re: [HACKERS] No: implied sort with group by
От | darrenk@insightdist.com (Darren King) |
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Тема | Re: [HACKERS] No: implied sort with group by |
Дата | |
Msg-id | 9801281402.AA42154@ceodev обсуждение исходный текст |
Список | pgsql-hackers |
> Not necessarily true; as I said, I get the same result as above (with the 980112 > source tree; have things changed since??). Perhaps you are running into the sorting > problem which seemed to be present on larger tables only? > > - Tom > > postgres=> select b,c,sum(a) from t1 group by b,c; > b|c|sum > -+-+--- > |x| 5 > |z| 3 > (2 rows) > > postgres=> select * from t1; > a|b|c > -+-+- > 1| |x > 2| |x > 2| |x > 3| |z > (4 rows) Hmmm...I have a snapshot from about ten days ago, I'll get something newer and try this again. I've been putting off getting a new one until I get the block size patch done. Annoying to put the changes back into a new src copy (but not as annoying as dealing with #(*&^! insurance companies claims departments). Is the order from the second query the order that the rows were inserted? Do you get the same results if you insert the (3,null,'z') second or third so the rows are stored out of order? I was getting my bad results with this same data, only four rows. I do have a problem with large groupings on two or more columns running out of memory, but not the problem that linux users are seeing. darrenk
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