Hi, While i was studying the unique index checks very closely, i realized that what we need is to find out whether the tuple is deleted / not. So say a tuple is deleted by a transaction, but it is not dead( because of some long running transaction ), still we can mark a hint bit as deleted and it will help the subsequent transactions doing the unique checks. As a matter of fact, it will help the deferred_unique cases, since it will anyway check the tuples twice, if there is a duplicate. So we have one bit left in the Index Tuple that can be used as hint bit. If we are ready to break the disk compatibility, then we can store the size as a multiple of 8, and we will get three bits free. Any comments?
Thanks, Gokul.
