Search age (aka last updated) with ChangeIndex
The age operator is implemented as a range query on the updated
ChangeField. To save space the value is represented as the number
of minutes since the epoch, removing about 16 bits from the 64 bit
timestamp. The field is stored to permit a future change to sort.
Aside from age also send sortkey_before and sortkey_after to the
ChangeIndex. These drive off the same updated field as age, and
round out the set of operators that support range queries.
With this complete the ChangeIndex can answer many common user
queries without hitting the database. Result sorting still loads
the change records, to be fixed in a future commit.
Change-Id: Ib8056f21d866904122d37241cc52f69a998b30c2
9 files changed
