Kouber Saparev wrote: > I tried to DELETE about 7 million rows at once, and the query went up to > 15% of the RAM (120 GB in total), which pushed some indexes out and the > server load went up to 250, so I had to kill the query. > > The involved table does not have neither foreign keys referring to other > tables, nor other tables refer to it. The size of the table itself is 19 GB > (15% of 120 GB). So why the DELETE tried to put the entire table in memory, > or what did it do to take so much memory?
Are there triggers in the table? Deferred triggers in particular can use memory. -- Álvaro Herrera http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services