Re: Bulkloading using COPY - ignore duplicates?
От | Lee Kindness |
---|---|
Тема | Re: Bulkloading using COPY - ignore duplicates? |
Дата | |
Msg-id | 15384.52447.737930.610518@elsick.csl.co.uk обсуждение исходный текст |
Ответ на | Re: Bulkloading using COPY - ignore duplicates? (Patrick Welche <prlw1@newn.cam.ac.uk>) |
Ответы |
Re: Bulkloading using COPY - ignore duplicates?
|
Список | pgsql-hackers |
Patrick Welche writes:> On Thu, Dec 13, 2001 at 01:25:11PM +0000, Lee Kindness wrote:> > That's what I'm currently doingas a workaround - a SELECT DISTINCT> > from a temporary table into the real table with the unique index on> > it. Howeverthis takes absolute ages - say 5 seconds for the copy> > (which is the ballpark figure I aiming toward and can achievewith> > Ingres) plus another 30ish seconds for the SELECT DISTINCT.> Then your column really isn't unique, That's another discussion entirely ;) - it's spat out by a real-time system which doesn't have the time or resources to check this. Further precision loss later in the data's life adds more duplicates... > so how about dropping the unique index, import the data, fix the> duplicates, recreate the unique index - just as anotherpossible> work around ;) This is just going to be the same(ish) time, no? CREATE TABLE tab (p1 INT, p2 INT, other1 INT, other2 INT);COPY tab FROM 'file';DELETE FROM tab WHERE p1, p2 NOT IN (SELECTDISTINCT p1, p2 FROM tab);CREATE UNIQUE INDEX tab_idx ON tab USING BTREE(p1, p2); or am I missing something? Thanks, Lee. -- Lee Kindness, Senior Software Engineer, Concept Systems Limited.http://services.csl.co.uk/ http://www.csl.co.uk/ +44 1315575595
В списке pgsql-hackers по дате отправления: