[Zope-dev] ZCatalog hackery

[Chris McDonough]

> Will the new data be 'made ready for indexing' before it is compared to
the
> existing data?  That is, will ZCatalog have to compute the data in some
> way before it compares it to what is already stored?

Yes.

> I'm wondering because it would be significant overhead to 'make a data
field
> of 100MBs into an index-like value' and then compare it to what already
> exists in the ZCatalog.

Yes, it's potentially slower on update but causes less database bloat.  Most
importantly the update scheme causes fewer ConflictErrors on heavy-write
sites because we're writing to the ZODB less often.  That said, some of the
operations of comparison in the indexing code are moving from Python to C,
which should offset this penalty a little.