[Xapian-discuss] Speeding up phrase queries

[Chris Olds]

I have a fairly large Xapian index (3.7M docs, 280+GB in 5 Flint indexes),
and I'm surprised by how slow phrase searching is in comparison to other
queries.
A search that (estimates that it) returns 20K documents for   ' a ( b NEAR c
)' takes 631 seconds, while ' a b c '  takes less than a second to return an
estimate of 40K docs.
Both searches return exactly the same top 10 documents.

I understand why phrase searching is more expensive than a simple 'AND'
query, but 10.5 minutes vs under a second is not what I'd expect.

Anyone have hints on what I could do to improve performance?

Xapian 1.0.6, Win2k3 Server, Dual-quad proc, 8GB RAM, 500GB of 15K RPM disk,
RAID 5.

Thanks for any help

/cco