Re: POC: Cleaning up orphaned files using undo logs - Mailing list pgsql-hackers

From Dilip Kumar
Subject Re: POC: Cleaning up orphaned files using undo logs
Date
Msg-id CAFiTN-vh9W9=xR2=XiOdFBV1tZnTeZ4Wnf6SWeMjupLwuetpMg@mail.gmail.com
Whole thread Raw
In response to Re: POC: Cleaning up orphaned files using undo logs  (Andres Freund <andres@anarazel.de>)
List pgsql-hackers
On Thu, Aug 22, 2019 at 9:58 AM Andres Freund <andres@anarazel.de> wrote:
>
> Hi,
>
> On 2019-08-22 09:51:22 +0530, Dilip Kumar wrote:
> > We can not know the complete size of the record even by reading the
> > header because we have a payload that is variable part and payload
> > length are stored in the payload header which again can be at random
> > offset.
>
> Wait, but that's just purely self inflicted damage, no? The initial
> length just needs to include the payload. And all this is not an issue
> anymore?
>
Actually, we store the undo length only at the end of the record and
that is for traversing the transaction's undo record chain during bulk
fetch.  Ac such in the beginning of the record we don't have the undo
length.  We do have uur_info but that just tell us which all optional
header are included in the record.

-- 
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com



pgsql-hackers by date:

Previous
From: Andres Freund
Date:
Subject: Re: POC: Cleaning up orphaned files using undo logs
Next
From: Andres Freund
Date:
Subject: Re: POC: Cleaning up orphaned files using undo logs