When changes are queried the hashtags are retured with each change.
These hashtags should be read from the change index rather than
loading them from NoteDb. Loading the change notes for each change in
the result set leads to poor query performance when NoteDb is enabled.
The existing HASHTAG field in the change index contains the lower case
hashtags to support case-insensitive queries by hashtag. To be able to
retrieve the hashtags with the original case from the index we must
add a new field that stores the hashtags with the original case. This
new field is not used for serving queries, hence it is of type
STORED_ONLY.
Change-Id: I0a9eb0ad0ac849d8b7b3ac6965dc8b5f38d04a32
Signed-off-by: Edwin Kempin <ekempin@google.com>
680495c014