Query rewrite

Oracle 10.1.0.3

We are just starting to work with data warehousing, and are having some problems with query rewrite. I need several materialized views that have a raw data type. This appears to mean that query rewrite will not work (although I haven't yet found a reason why - does anyone have a reference). Whilst playing around with this, another quirk has shown up.

If I turn query rewrite off (alter session), then when I run dbms_mview.explain_rewrite, I get an entry in the rewrite_table saying that query rewrite is turned off (so it looks as though that is set up properly), however when query rewrite is enabled, I don't get any messages when I ask for an explain. Reading the Data warehousing guide, it looks as though I would get an entry when a rewrite is possible, so should I get one when it is not possible ?

Whilst we are looking at 10g at the moment for this, it is probable that in the interim we will have to use 9.2.0.5 for the real implementation, are there likely to be any serious problems in this area between the two versions.

TIA Adrian

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