: Can solr take the earliest date from the result set to be the value for
: "facet.date.start"? I dont want to have the value 1/1/1995 hardcoded in my
: application since a new data feed that gets into my index could be older
: than 1995 and i might keep missing them from the facet.
no, you have to pick a start and end date.
In most use cases, people pick a start date and gap size that is some
convinient order of magnitutde relative the time ranges they wnat to deal
in. ie: "I want to let people facet by year for the past 10 years" that
woud result in...
facet.date.start=NOW/YEAR-1YEAR
facet.date.gap=+1YEAR
facet.date.end=NOW/YEAR+1YEAR
...likewise you could said "I want to let people facet by month for the
past year" etc...
where facet.date.other and before/after come in handy is to people able to
tell your users "here are hte facet counts for each year of hte past 10
years, and there are X documents odler then that" If people want to see
older documents, then you can refine your start/end (and maybe even gap)
to show them facets for those older years (maybe you keep a gap of 1YEAR
and just shift the start, maybe you switch to a gap of 10YEARS and use a
start that's 100 years ago?)
Solr Faceting doesn't offer a means to pick the "lowest" value in the
index, because it's usually either:
1) something useful, but you already know that and know what it is and can
easily configure it manually (ie: 1995 for you)
2) something so useless it would provide a terrible usecase if it was used
by default so you really have to configure it manually (ie: if your docs
span hundrads of years and you want to show counts per month it would be
painful to show every month for the past 500 years by default)
3) something that fluctuates as the index changes and would result in an
inconsistent user experience so it would be undesirable (ie: one day
you're offering to facet per year for hte past 10 years, the next day
you're offering to facet per year for the past 47 years)
Note: if you take advatnage of the "key" localparam, you can facet on the
same field with multiple date ranges (ie: facet per year for the last 10
years, and facet per decade for the past 100 years) in a single request --
so that might come in handy for you...
https://wiki.apache.org/solr/SimpleFacetParameters#key_:_Changing_the_output_key
-Hoss
