Re: fetching bytea (blob) data of 850 MB from psql client failed

On Mon, Aug 29, 2022 at 1:02 PM jitesh tiwari <jitesh120(at)gmail(dot)com> wrote:
>
> Hi John,
> Thanks for those details.
> The database table for bytea columns has binary data data and some are not text. Hence, when it tried to fetch by changing the bytea_output to 'escape' it failed again with the below error -
> VERROR; result of bytea output conversion is too large(File varlena.c; Line 415; Routine byteaout; ).
> BTW, is there any plan to fix this issue in the PostgreSQL backend code in near future?

Unfortunately, there is no plan as there is no consensus on how to
approach the issue. It seems the possible actions are (easiest to
hardest):

1. Document that bytea is unsafe -- you can insert anything you like,
but you may be unable to retrieve it again.
2. Determine some maximum size that guarantees accessibility and
invent a GUC that by default prevents inserting larger values than
that.
3. Fix the issue properly.

#2 and #3 are challenging for reasons given in the thread I linked to above.

--
John Naylor
EDB: http://www.enterprisedb.com