Files
scylla/db/view
Duarte Nunes b8b8a8099c view_updates: Compute row marker
This patch adds a function to compute the row marker of a view row
given the base row. There are two cases to consider when building the
row marker: 1) there is a column C that is a regular base column but
is in the view PK; and 2) the columns for the base and the view PKs
are the same.

For 1), the view row marker timestamp will be the biggest between the
base's row marker and C. The TTL will be that of C. This means that if
C expires, the view row maker will expire as well (and the row, if no
other column is keeping it alive). Note that if the base row marker
expires but not C, then the base row will still be live due to C and
we shouldn't expire the view row.

For 2), the view row timestamp will be the same as the base row
timestamp. The TTL should be set in such a way that both base and view
rows live for the same time. We thus set the view row TTL to be the
max of any other TTL in the base row. This is particularly important
in the case where the base row marker has a TTL, but a column *absent*
from the view holds a greater one.

Signed-off-by: Duarte Nunes <duarte@scylladb.com>
2017-02-06 13:35:31 +01:00
..
2017-02-06 13:35:31 +01:00