Re: [HACKERS] Plans for solving the VACUUM problem

[Vadim Mikheev]

> Yes, that is a good description. And old version is only required in the following 
> two cases:
> 
> 1. the txn that modified this tuple is still open (reader in default committed read)
> 2. reader is in serializable transaction isolation and has earlier xtid
> 
> Seems overwrite smgr has mainly advantages in terms of speed for operations
> other than rollback.

... And rollback is required for < 5% transactions ...

Vadim



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