Setting up boost per document (per logged in user) - proper way to structure?

Hi there,

ElasticSearch newbie here. I'm trying to build a search platform that
will add boost to specific documents based on user selection. For
example, using the query "foo" if I have the following hits with their
scores:

Foo 1
Bar 2
Baz 3

.. if I were to click on Baz, the subsequent fuzzy search query for
"foo" would put Baz at the top. My thinking was to set up a boost
field per document (following this: http://www.elasticsearch.org/guide/reference/mapping/boost-field.html
), and increment the boost value on user click. I was also thinking of
creating a new index per user. Is this the correct way to approach
this? I would only have about 10 users and thus 10 indexes per
instance, but the data set is a good size (3mm records). Should I be
approaching this using a different method? Also, for optimal searches
for "foo" to immediately match "Foo" as result 1, should I be using
the "text" query method?

Thanks in advance.