Changes to default search options

[Gervase Markham]

Analysis of the "This query was killed for taking too long" logs on 
bugzilla.mozilla.org, which give a good indication of which queries 
people are running that take up a lot of resources, leads me to suggest 
the following changes to bugzilla.mozilla.org's default search options. 
The question is, do we make these to Bugzilla, the software, as well?

- Default email searches to "exact match"
   http://bugzilla.mozilla.org/show_bug.cgi?id=173567
   Exact match searches are far less resource-intensive, and evidence
   from the logs shows that people are typing in full email addresses
   and doing substring searches, which is silly. If we default to exact,
   and they type in a substring and search, they get Zarro, quickly,
   and adjust their parameters. Better that than the other way round.

- Default text search boxes to "contains string"
   http://bugzilla.mozilla.org/show_bug.cgi?id=173689
   People often type in a string like "unable to close dialog" to search
   the comments for, and then hit "Search"; the current default returns
   a list of all bugs with at least one comment with any of those four
   words in. As well as being useless, this is very time-consuming.

- Pre-select Browser and MailNews
   http://bugzilla.mozilla.org/show_bug.cgi?id=173573
   (This also requires a priority sorting of the product list on the
   search page.) This default selection will a) be what most people
   want, b) reduce the number of bugs that are searched by default,
   c) produce more sensible initial default component and milestone
   lists. (This one is obviously b.m.o.-only.)

In all of these, the principle I am adopting is that we should default 
to an option which uses less resources.

Your comments are welcome, both from a code and a usability perspective.

Gerv