http://www.alexa.com/site/company/announcement
My site’s ranking has changed. Was it wrong before?
Your ranking wasn’t wrong before, but it was different. Alexa toolbar users’ interests and surfing habits could differ from those of the general population in a number of ways, and we described some of those possible differences on our website. While the vast majority of sites’ rankings were unaffected by such differences, we’ve worked hard on our new ranking system to adjust for situations in which they could matter.
The new rankings should better reflect the interests and surfing habits of the broader population of Web users.
mailing list: pgsql-admin.postgresql.org
from: Johann Spies
..loaded about 4,900,000,000 in one of two tables with 7200684 in the second table in database ‘firewall’, built one index using one date-field (which took a few days) and used that index to copy about 3,800,000,000 of those records from the first to a third table, deleted those copied record from the first table and dropped the third table.
This took about a week on a 2xCPU quadcore server with 8Gb RAM..
—
Table paritioning is need.
distribute tables across different disks through tablespaces.Tweak the shared buffers and work_mem settings.
RAID5/6 are very,very slow when it comes to small disk *writes*.
At least a hardware RAID controller with RAID 0 or 10 should be used, with 10krpm or 15krpm drives. SAS preferred.
as on SATA the only quick disks are Western Digital Raptor.
look at a view called pg_stat_activity. Do: select * from pg_stat_activity;
