Обсуждение: random_page_cost for tablespace
Hi All, We have a bigger table with some million rows. Number of index scans is high, number of seq reads is low. This table if often joined with others... so we want to buy a new SSD drive, create a tablespace on it and put this big table on it. Random read speed on SSD is identical to seq read. However, I need to tell the optimizer that random_page_cost is less for the new tablespace. Is there a way to do it? Thanks, Laszlo
2009/11/9 Laszlo Nagy <gandalf@shopzeus.com>: > We have a bigger table with some million rows. Number of index scans is > high, number of seq reads is low. This table if often joined with > others... so we want to buy a new SSD drive, create a tablespace on it > and put this big table on it. Random read speed on SSD is identical to > seq read. However, I need to tell the optimizer that random_page_cost is > less for the new tablespace. Is there a way to do it? I happen to be working on a patch for this exact feature. However, even assuming it gets in, that means waiting for 8.5. ...Robert
Robert Haas írta: > 2009/11/9 Laszlo Nagy <gandalf@shopzeus.com>: > >> We have a bigger table with some million rows. Number of index scans is >> high, number of seq reads is low. This table if often joined with >> others... so we want to buy a new SSD drive, create a tablespace on it >> and put this big table on it. Random read speed on SSD is identical to >> seq read. However, I need to tell the optimizer that random_page_cost is >> less for the new tablespace. Is there a way to do it? >> > > I happen to be working on a patch for this exact feature. However, > even assuming it gets in, that means waiting for 8.5. > That will be a very nice feature. Thank you! :-)