PostgreSQL 8.0 Released
Christopher Cashell writes "The PostgreSQL project has released version 8.0 of their well known Object-Relational Database. New features include: Win32 Native Server, Savepoints, Point-In-Time Recovery, Tablespaces, and lots more. Downloads are available via bittorrent for Unix/Linux, and the much anticipated Win32 version, or via ftp (use a mirror!)." (Here's the official announcement.)
Great, but why should I use PostgreSQL when I already have a database, you might ask? Here's why.
Hi Folks,
Please take it easy on 'wwwmaster'.
'www' fell over a couple of hours ago, and a couple of mirrors are coming online to round-robin the address.
Can someone please change the the first link ("PostgreSQL project") in the story to point to 'www'?
Thanks.
Not only that. Here's the most important link: What's New in 8.0. (To editors: why there are links to torrents, but no link to features?)
Sincerely,
Pan Tarhei Hosé, PhD.
"Homo sum et cogito ergo odi profanum vulgus et libido."
In MySQL (with MyISAM tables), the reason things like count(*) are fast is that MyISAM pre-computes those values. It can do this because it locks the table on insert and update. PostgreSQL doesn't lock the table on modifications -- it allows concurrent access via Multi-Version Concurrency Control (MVCC). Basically, each row in the DB has additional information (used internally by PostgreSQL), which stores which transaction created and last modified the row. PG uses this to determine if any given row should be "visible" to the current transaction. Because this informaiton is constantly changing (and varies from transaction to transaction), you can't precompute things like count(*) and sum(*). See http://developer.postgresql.org/pdf/internalpics.p df for more info (start around page 56).