The fields that are used for sorting must be added to the document. This
means the documents in the index must be all recomputed, hence we need
new index schema versions for the affected indexes.
The sorting that is done by Lucene for the account index must match the
sorting of accounts that is already done in QueryAccounts before
returning query results to clients. QueryAccounts sorts results by
fullname, preferred email and account ID. If Lucene would do a different
sorting limited queries may return wrong results. E.g. if there are 3
accounts, Foo (ID=1), Bar (ID=2) and Baz (ID=3), which are all matched
by a query for which the results are limited to 2, callers of
QueryAccounts expect Bar and Baz to be returned since QueryAccounts
promises sorting by fullname. If now Lucene would sort by account ID,
Lucene would find Foo and Bar, Baz would be skipped since it's over the
limit. These results are then handed over to QueryAccounts which does
sorting by name so that Bar and Foo are returned to the client. This
would be wrong since the caller expects Bar and Baz. It's a bit unclear
how this worked when Lucene was not doing proper sorting at all, maybe
it was just luck that the withLimit test succeeded before. As Lucene
does the sorting properly now, the sorting in QueryAccounts could be
removed, but since Lucene is not the only index implementation and other
index implementation may still have sorting issues we keep that sorting
in QueryAccounts for now.
Bug: Issue 10210
Change-Id: Ic59e4d330fe8c7198023ddbc2fa946cf5db80b63
Signed-off-by: Edwin Kempin <ekempin@google.com>
(cherry picked from commit 714f7d3c3f)
f70d14d2ac