On Mon, Jun 13, 2011 at 10:47, Shane Hathaway <sh...@hathawaymix.org> wrote: >> I am kind of wondering as to why a base64 encoding is needed at all. >> The psycopg supports the required encoding / decoding steps natively >> for both escape formats, and will do so transparently. See: >> >> http://initd.org/psycopg/docs/usage.html#index-7 >> >> Not encoding ZODB pickles for the object_state table from and to >> base64 would save a lot of space (base64 encoding expands data to 133% >> it's original size, leading to up to 1/3rd more space required to >> store a Zope ZODB in PostgreSQL than in other databases. > > No, the base 64 encoding is only used for database communication. In > all databases RelStorage supports, objects are stored in binary form > with no encoding. > > Early on in the project I found out by measurement that the standard > binary encoding used by psycopg was a lot slower than base64 encoding. > I was trying to get PostgreSQL to match the MySQL numbers I was seeing. > I didn't quite accomplish that, but base64 brought it closer.
Right, that's an excellent reason to keep the base64 encoding then! Perhaps this should be documented in the package, or is there a design decisions doc somewhere else that we can add to (or where I should have looked and missed this)? :-) > WRT using PostgreSQL OIDs for blobs: the extra burden of deleting unused > OIDs doesn't seem worth the extra effort to me. I would be happy to > hear that you found a reasonably simple way to do it. My guess is that > an on-delete trigger will be the best way. Already solved with a trigger, see http://zope3.pov.lt/trac/changeset/121922/relstorage/branches/postgres_blob_oid :-) The trigger is really really simple; the example I first found had to deal with UPDATE too, making things a little more complicated, but RelStorage never does that; it's either INSERT or DELETE. -- Martijn Pieters _______________________________________________ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org https://mail.zope.org/mailman/listinfo/zodb-dev
