We apply deletion of scylla_tables.version to the incoming schema
mutations so that table schema version is recalculated after merge.
The mutations which we read from local schema tables may not have it
deleted in which case all tables would be considered as differing on
the presence of the version field. Avoid this by deleting the field
from old mutations as well.
Digest only looks like live values, ignoring deletion
information. Equality should be consistent with that, so that schemas
considered equal do not trigger the alter path unnecessarily.
It will be used to store Scylla spcific table metadata. We cannot
store it in the standard "tables" table for compatibility reasons -
Cassandra will fail to read schema if it encounteres columns it is not
expecting.
This patch allows a view schema to be frozen. To unfreeze such a
schema, we add an is_view attribute to the schema idl.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
We must use canonical_mutation form to allow for changes in the schema
of schema tables. The node which deserializes schema mutations may not
have the same version of the schema tables so we cannot use
frozen_mutation, which is a schema dependent form.
