CurtMonash writes: "Web analytics databases are getting every larger. eBay now has a 6 1/2 petabyte warehouse running on Greenplum — user data — to go with its more established 2 1/2 petabyte Teradata system. Between the two databases, the metrics are enormous — 17 trillion rows, 150 billion new rows per day, millions of queries per day, and so on. Meanwhile, Facebook has 2/12 petabytes managed by Hadoop, not running on a conventional DBMS at all, Yahoo has over a petabyte (on a homegrown system), and Fox/MySpace has two different multi-hundred terabyte systems (Greenplum and Aster Data nCluster). eBay and Fox are the two Greenplum customers I wrote in about last August, when they both seemed to be headed to the petabyte range in a hurry. These are basically all web log/clickstream databases, except that network event data is even more voluminous than the pure clickstream stuff."