Cassandra supports a "CREATE CUSTOM INDEX" to create a secondary index
with a custom implementation. The only custom implementation that Cassandra
supports is SASI. But Scylla doesn't support this, or any other custom
index implementation. If a CREATE CUSTOM INDEX statement is used, we
shouldn't silently ignore the "CUSTOM" tag, we should generate an error.
This patch also includes a regression test that "CREATE CUSTOM INDEX"
statements with valid syntax fail (before this patch, they succeeded).
Fixes#3977
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20181211224545.18349-2-nyh@scylladb.com>