Large fetch sizes have potentially deleterious effects on VM memory requirements when using Oracle

Since Release 10g, Oracle JDBC drivers use the fetch size to allocate buffers for caching row data.
cf. http://www.oracle.com/technetwork/database/enterprise-edition/memory.pdf

r1060431 hard-codes the fetch size for all ResultSet-returning statements to 10,000. This value has significant, potentially deleterious, effects on the heap space required for even moderately-sized repositories. For example, the BUNDLE table (from 'oracle.ddl') has two columns – NODE_ID raw(16) and BUNDLE_DATA blob – which require 16 b and 4 kb of buffer space, respectively. This requires a buffer of more than 40 mb [(16+4096) * 10000 = 41120000].

If the issue described in JCR-2832 is truly specific to PostgreSQL, I think its resolution should be moved to a PostgreSQL-specific ConnectionHelper subclass. Failing that, there should be a way to override this hard-coded value in OracleConnectionHelper.