Hello Kevin, Thnks for response, Doing the alter table to add the new column was fast: ALTER TABLE table1 ADD COLUMN new_column date;
The problem is that I have to do a update in this column, and the values are going to be the a misc of others 2 columns of the table1, something like this: update table1 set new_column = (date) where new_column is null; Postgres Version: 8.3.6 Os.: Fedora Core 9 4 Gb Ram On Thu, Apr 23, 2009 at 2:29 PM, Kevin Grittner <kevin.gritt...@wicourts.gov > wrote: > Rafael Domiciano <rafael.domici...@gmail.com> wrote: > > > I have a large table to do update (in every tuple), the table > > (table1) has about 8 millions tuples, and I had to add a new column > > (new_column). The table1 is one of the most accessed table in my > > cluster, so I can't do a direct update 'cause almost everyone stays > > in waiting. Doing the update at night was unsuccesful, in the > > morning it was running yet, and we had to kill it. > > Doing that with an ALTER TABLE against only 8 million rows should > probably not have taken all night (depending, of course, on a lot of > details you haven't provided). Killing it after running for all those > hours will have bloated your tables and indexes. (Perhaps they were > already bloated, in which case this will have made it worse.) > > What version of PostgreSQL is this, on what OS? > > What does a VACUUM ANALYZE VERBOSE on this table show as output? INFO: "table1": encontrados 1572 versões de registros removíveis e 8022357 não-removíveis em 244388 páginas DETAIL: 7101 versões de registros não vigentes não podem ser removidas ainda. Havia 1657653 ponteiros de itens não utilizados. 62515 páginas contém espaço livre útil. 0 páginas estão completamente vazias. CPU 9.38s/26.74u sec elapsed 27540.53 sec. > > > What are the last few lines of VACUUM ANALYZE VERBOSE on the whole > database? INFO: mapeamento de espaço livre contém 152886 páginas em 907 relações DETAIL: O total de 151280 páginas estão em uso (incluindo excesso). 151280 páginas são necessárias para encontrar todo espaço livre. Limites atuais são: 153600 páginas, 2500 relações, utilizando 1065 kB. > > > If you can show us the table description and how you tried to modify > it, that would help. > > -Kevin >
