Brain-Dead Sort Algorithm??
От | Tim Perdue |
---|---|
Тема | Brain-Dead Sort Algorithm?? |
Дата | |
Msg-id | 199912031432.GAA19000@www.geocrawler.com обсуждение исходный текст |
Ответы |
Re: [HACKERS] Brain-Dead Sort Algorithm??
|
Список | pgsql-hackers |
This message was sent from Geocrawler.com by "Tim Perdue" <tim@perdue.net> Be sure to reply to that address. > >It uses over 1GB of disk space to do that sort, > >and it would have used a lot more if I hadn't run > >out. > > > >Then it won't fail gracefully, instead of just > >hangs and leaves temp files completely filling up > >the hard drive. > Because maybe you're doing a really dumb join before you > sort? SQL is full of such "gotchas". No, sorry. select distinct serial into serial_good from serial_half; serial_half is a 1-column list of 10-digit numbers. I'm doing a select distinct because I believe there may be duplicates in that column. The misunderstanding on my end came because serial_half was a 60MB text file, but when it was inserted into postgres, it became 345MB (6.8 million rows has a lot of bloat apparently). So the temp-sort space for 345MB could easily surpass the 1GB I had on my hard disk. Although how anyone can take a 60MB text file and turn it into > 1GB is beyond me. > And, of course, you've posed your question stupidly - "my query's > slow, why is Postgres so horrible?" and you haven't bothered posting > your query. None of that was ever stated. Actually what was stated is that it is retarded to fill up a hard disk and then hang instead of bowing out gracefully, forcing the user to manually delete the temp_sort files and kill -9 postgres. You can't argue with that portion. And it happens on v6.4, v6.4.2, and v6.5.2 on RHAT 6.1, and LinuxPPC. Yes, my post was rather harsh - I posted it when I was pissed and that was a mistake. I had this same problem in March when trying to sort a 2.5GB file with 9GB free. I use postgres on every project I work on, including this site, Geocrawler.com, and my PHPBuilder.com site, because it's a decent and free database and it will scale beyond 2GB, unlike MySQL. Tim Geocrawler.com - The Knowledge Archive
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