Default operator for Omega

[Olly Betts]

Currently Omega defaults to OP_OR, but these days other search engines have trained users to expect an AND search by default.

I think we should consider changing the default for the next release series, so setting milestone to 1.3.0.

[laserbled]

These are 2 changes to change OR to AND operation.

[laserbled]

filter_vec.push_back(Xapian::Query(Xapian::Query::OP_OR,

Xapian::Query::op default_op = Xapian::Query::OP_OR; default matching mode

hope those are the only required once....Am not sure what to do about the OR operations in xapian core and search stuffs.

[Olly Betts]

Actually, only the first hunk of that patch is relevant here.

The second hunk is to do with how filters with the same prefix are combined (which ought to be configurable - see ticket #234 - but that's not the default operator for query parsing, it's about what happens with multiple B CGI parameters specifying filter terms with the same term prefix).

But if you build with your change, add $querydescription to the end of templates/query and then run a query, you'll see that while the default is now OP_AND, explicitly specifying DEFAULTOP=OR doesn't work:

olly@atreus:~/svn/xapian/xapian-applications/omega$ echo '$querydescription' >> templates/query
olly@atreus:~/svn/xapian/xapian-applications/omega$ OMEGA_CONFIG_FILE=omega.conf ./omega P='hello world' |tail -1
Xapian::Query((Zhello:(pos=1) AND Zworld:(pos=2)))
olly@atreus:~/svn/xapian/xapian-applications/omega$ OMEGA_CONFIG_FILE=omega.conf ./omega DEFAULTOP=OR P='hello world' |tail -1
Xapian::Query((Zhello:(pos=1) AND Zworld:(pos=2)))

We also need to change where default_op gets set from the DEFAULTOP CGI parameter, in omega.cc. And the documentation needs updating to reflect the new default too (ideally with a note that the default was OR in versions prior to 1.3.0, or whenever this gets applied).

[laserbled]

Document updates

[Olly Betts]

Fixed in r16204.