Read the Rules section of the manual and the section on Rules vs Triggers. >From what I get triggers are necessary for column constraints. As far as speed, it seems there are some differences between how fast rules/triggers would do the same action, but that some complex analysis is involved to determine this. And I gathered rules are necessary to allow update/insert/delete actions on views. Can anyone give me some simple reasons why they choose rules over triggers in their real-world dbs? -- Randall Perry sysTame Xserve Web Hosting/Co-location Website Development/Promotion Mac Consulting/Sales http://www.systame.com/ ---------------------------(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
