Hello,everyone,	I want to know how postgres remain its unique index unique after i have change it,Forexample:	CREATE TABLE human(age INT,name CHAR(30));then in pg_attribute catalog the unique index pg_attribute_relid_attnum_index will use the relid of'human' and attnum of age to create a index tuple for attribute:age,which is a unique index tuple describingage ,then i do：	ALTER TABLE human RENAME　age TO birthdate;in the unique index pg_attribute_relid_attnum_index will appear two index tuple which keys are relid of 'human'and attnum:1 to describe age(In my mind,when insert or update a heap tuple,postgres only inserts a new index tuple for it in its index relation if it has not delete or tag the old index tuple),but there is no errorhappening!!!!So i am interested in the method of remianing the dynamic index unique very much.	would you please tell me how postgres completes it and the src of this?thank:)						庄继锋 						２００４－４－３０





==========================
263电子邮件－信赖邮自专业





==========================
263电子邮件－信赖邮自专业
Fri, 30 Apr 2004 12:59:09 +0800
=?gb2312?B?emh1YW5namlmZW5n?= <zhuangjifeng@263.net>
How does postgres remain the unique index unique?