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>
This patch introduces the view_updates class, which is responsible
for generating and storing updates to a particular materialized view.
The updates will be generated from an updated base row and the
pre-existing one (if any), in later patches.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
To help calculate the view mutations from a base update, we store in
the view class the column that's part of the view's primary key but
not part of the base's, if such column exists.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
This patch adds the matches_view_filter() function which specifies
whether a given base row matches the view filter. Unlike
may_be_affected_by(), this function has no false positives.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
This patch adds the may_be_affected_by() function to the view class,
which is responsible to determine whether an update to a base class
affects one of its views.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
This patch adds an utility function that creates a raw select
statement from a set of columns and a where clause. It is intended to
be used to create the prepared select statement used by the view
class.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
This patch adds the view class, which will contains functions related
to populating a view, either from the base table's write path or from
the view building mechanism which copies over already existing data in
the base table.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
