Re: Size of TOAST pointer - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Size of TOAST pointer
Date
Msg-id 13171.1437086998@sss.pgh.pa.us
Whole thread Raw
In response to Size of TOAST pointer  (Vignesh Raghunathan <vignesh.pgsql@gmail.com>)
List pgsql-hackers
Vignesh Raghunathan <vignesh.pgsql@gmail.com> writes:
> I was looking at the documentation for TOAST (
> http://www.postgresql.org/docs/devel/static/storage-toast.html) and it's
> specified that the toast pointer occupies 18 bytes. However, the struct
> representing the toast pointer is defined as follows
> typedef struct varatt_external

The data that actually ends up on disk is a varattrib_1b_e wrapping a
varatt_external, and that header is where the extra 2 bytes come from.
        regards, tom lane



pgsql-hackers by date:

Previous
From: Vignesh Raghunathan
Date:
Subject: Size of TOAST pointer
Next
From: Peter Geoghegan
Date:
Subject: Memory prefetching while sequentially fetching from SortTuple array, tuplestore