On Tue, Apr 28, 2015 at 2:31 AM, Jim Nasby <jim.na...@bluetreble.com> wrote: > > On 4/25/15 12:12 AM, Amit Kapila wrote: >> >> > ... which isn't possible. You can not go from a heap tuple to an >> index tuple. >> >> We will have the access to index value during delete, so why do you >> think that we need linkage between heap and index tuple to perform >> Delete operation? I think we need to think more to design Delete >> .. by CTID, but that should be doable. > > > The problem with just having the value is that if *anything* changes between how you evaluated the value when you created the index tuple and when you evaluate it a second time you'll corrupt your index. >
I think I am missing something here, but when this second evaluation is needed. Basically what I understand from index insertion is that it evaluates the value to be inserted in index before calling nbtree module and then nbtree just inserts the value/tuple passed to it. With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com
