Re: Questions about octal vs. hex for bytea

Been using bytea heavily through JDBC. In transitioning to 9.0 I've found the need to set the bytea_output parameter but otherwise everything else works the same as it did before.

As for storage space concerns I do not know for sure but the numbers cannot be that substantial to warrant changing an existing database unless large binary processing takes up a significant portion of the processing (as opposed to simple document storage and retrieval which is what I am doing).

David J.

-----Original Message-----
From: pgsql-general-owner(at)postgresql(dot)org [mailto:pgsql-general-owner(at)postgresql(dot)org] On Behalf Of Reuven M. Lerner
Sent: Sunday, February 20, 2011 6:31 AM
To: pgsql-general(at)postgresql(dot)org
Subject: [GENERAL] Questions about octal vs. hex for bytea

Hi, everyone. I've got a client who is planning to upgrade from PostgreSQL 8.3 to 9.0 in the coming weeks. They use a lot of tables with bytea columns. They're worried about the switch from octal to hex formats for bytea data.

Based on everything I know and have read, the change is only for external representations, for input and output. Output is now by default in hex, but can be changed with a parameter (bytea_output) that provides backward compatibility. Input can be in either octal or hex, with no changes needed.

My client is concerned that the internal representation has changed, and is asking me for a script that will change the representation, in order to save space (since hex occupies less space than octal). I'm not aware of such a need, or even the possibility for this to be done; even if the internal representation has changed, it'll be handled in the upgrade process, and doesn't need to be done with anything external.

So I've told them that I don't think that anything is necessary for either input or output, except (perhaps) to set bytea_output in its backward-compatibility mode. But I wanted to check with people here, just to double-check my understanding.

Thanks in advance,

Reuven

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