Merlin Moncure wrote: > > In Sybase ASE (and I'm pretty sure the same is true in Microsoft SQL > > Server) the leaf level of the narrowest index on the table is scanned, > > following a linked list of leaf pages. Leaf pages can be pretty dense > > under Sybase, because they do use prefix compression. A count(*) > > on a table with 100 million rows is going to take a few minutes, but > it > > is going to be at least an order of magnitude faster than a data page > > scan -- maybe two orders of magnitude faster. > > MS SQL server (pre 2005) is not an MVCC database, so it's not apples to > apples with pg.
Oh, also it was mentioned on pgsql-advocacy that InnoDB is MVCC. If that's the case, I wonder how do they do the count(*) thing? Is it fast? -- Alvaro Herrera http://www.CommandPrompt.com/ PostgreSQL Replication, Consulting, Custom Development, 24x7 support ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
