Two questions, need help soon
От | John Zhuang |
---|---|
Тема | Two questions, need help soon |
Дата | |
Msg-id | C08F3481F73ED211938100A0C95FC4DF2466@odin.jatotech.com обсуждение исходный текст |
Список | pgsql-general |
> I have 2 questions about postgres. I recently installed postgreSQL on > Solaris 2.5.1. > 1. the pgaccess does not work, when I type "wish -f pgaccess.tcl", > it gave the following error messages: > Error in startup script: couldn't load file "libpgtcl.so": > ld.so.1: wish: elf error: /usr/local/pgsql/lib/libpgtcl.so: wrong > class or data encoding > while executing > "load libpgtcl.so" > (procedure "main" line 3) > invoked from within > "main $argc $argv" > (file "pgaccess.tcl" line 4683) > This library: "libpgtcl.so" and "libpq.so" were downloaded from the > web site of www.flex.ro/pgaccess. They were writen for Redhat Linux, > so it is not strange that it doesn't work. But how do I make pgaccess > without the library "libpgtcl.so", is there any other way to do it? > > 2. The database's performance is kind of slow when I tried "select > distinct", perhaps this is only the special case. I had this table > containing regression test data, right now ~10,000 rows, but only > contain 4 testdate (Oct 9 - Oct12), testdate is one of the field. So, > there are many repeated rows of the same testdate, and it takes 3 > minutes to get the results. The query is "select distinct testdate > from table", and the result is 4 rows of testdates. But if I use the > query: " select distinct testdate, machine, result, filelist from > table;", it runs significantly faster, it takes about 12 seconds to > give 66 rows of results. > > I do not know how "select distinct" is implemented in postgresql, > to me it seems that it used some algorithm that if the repeated values > are large, then the speed is much slower. Is there anyway to speed up? > > Thanks a lot. > > John Zhuang > Jato Technologies
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