On 8/25/2004 1:32 AM, Greg Stark wrote:
A dirty read is a read that includes data that hasn't been committed yet. Or as the SQL 92 standard puts it:
[...]
It could also be useful for referential integrity checks since, for example, it would let you see if someone has deleted the referenced record but not committed the delete yet.
But that alone wouldn't let you avoid locking the record, TODO items are mostly just pointers to old threads on the mailing lists. They don't contain the complete story. You could maybe find more information searching the pgsql-hackers archive on the web site.
Plus ... wouldn't doing the "on delete" lookup as dirty reads let referencing rows that have been deleted but still could come back through a rollback disappear? What you want to see are new tuples of uncommitted insert/update as well as old tuples of uncommitted delete/update. I don't think there is any term in the standard for that read mode, so we should call it dusty-reads because they see everything vacuum is interested in.
Jan
-- #======================================================================# # It's easier to get forgiveness for being wrong than for being right. # # Let's break this rule - forgive me. # #================================================== [EMAIL PROTECTED] #
---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings
