apache/cassandra · error · MaterializedViewNotFound

Materialized view '{}' not found

Error message

Materialized view '{}' not found

What it means

Shell.get_view_meta looks up a materialized view in KeyspaceMetadata.views. If the view name is absent it raises MaterializedViewNotFound. Views are keyspace-scoped and live in their own metadata collection, separate from tables.

Source

Thrown at pylib/cqlshlib/cqlshmain.py:610

            raise ColumnFamilyNotFound("Column family {} not found".format(tablename))

    def get_index_meta(self, ksname, idxname):
        if ksname is None:
            ksname = self.current_keyspace
        ksmeta = self.get_keyspace_meta(ksname)

        if idxname not in ksmeta.indexes:
            raise IndexNotFound("Index {} not found".format(idxname))

        return ksmeta.indexes[idxname]

    def get_view_meta(self, ksname, viewname):
        if ksname is None:
            ksname = self.current_keyspace
        ksmeta = self.get_keyspace_meta(ksname)

        if viewname not in ksmeta.views:
            raise MaterializedViewNotFound("Materialized view '{}' not found".format(viewname))
        return ksmeta.views[viewname]

    def get_object_meta(self, ks, name):
        if name is None:
            if ks and ks in self.conn.metadata.keyspaces:
                return self.conn.metadata.keyspaces[ks]
            elif self.current_keyspace is None:
                raise ObjectNotFound("'{}' not found in keyspaces".format(ks))
            else:
                name = ks
                ks = self.current_keyspace

        if ks is None:
            ks = self.current_keyspace

        ksmeta = self.get_keyspace_meta(ks)

        if name in ksmeta.tables:

View on GitHub (pinned to 88fd0f6a0e)

Solutions

  1. Run DESCRIBE MATERIALIZED VIEWS (or DESCRIBE KEYSPACE) and correct the view name.
  2. Qualify the view with the correct keyspace.
  3. Refresh schema metadata / reconnect if the view was just created.
  4. Create the view with CREATE MATERIALIZED VIEW if it does not exist.

Example fix

// before
shell.get_view_meta('ks', 'user_by_email')  # MaterializedViewNotFound
// after
shell.get_view_meta('ks', 'users_by_email')  # exact view name
Defensive patterns

Strategy: validation

Validate before calling

ksmeta = shell.get_keyspace_meta(ksname)
if viewname not in ksmeta.views:
    raise LookupError(f"View {viewname} missing in {ksname}")

Type guard

def view_exists(shell, ksname, viewname):
    return viewname in shell.get_keyspace_meta(ksname).views

Try / catch

try:
    vmeta = shell.get_view_meta(ksname, viewname)
except MaterializedViewNotFound:
    vmeta = None  # fall back to table lookup or re-describe

Prevention

When it happens

Trigger: get_view_meta(ksname, viewname) with viewname not in ksmeta.views — commonly via parse_for_select_meta when a SELECT targets a materialized view that does not exist under that name/keyspace.

Common situations: Querying a view that was dropped; typo in the view name; view exists in a different keyspace; stale driver metadata right after CREATE MATERIALIZED VIEW.

Understand the failure class

Background: "Not found" and "does not exist" errors: why "Task not found", "No such folder", and "Can't find" fire when a lookup comes back empty — this error's family across 14 libraries.

Related errors

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/b331f4fadd059cc2. Report an issue: GitHub.