apache/cassandra · error · InvalidRequestException

Primary key columns %s must be restricted with 'IS NOT NULL'

Error message

Primary key columns %s must be restricted with 'IS NOT NULL' or otherwise

What it means

Every primary key column of a materialized view must be explicitly restricted in the WHERE clause - either bound to a constant or restricted with IS NOT NULL. Unrestricted view key columns would be null-able and cannot form valid view row identities.

Source

Thrown at src/java/org/apache/cassandra/cql3/statements/schema/CreateViewStatement.java:324

            new StatementRestrictions(state,
                                      StatementType.SELECT,
                                      table,
                                      IndexHints.NONE,
                                      whereClause,
                                      VariableSpecifications.empty(),
                                      Collections.emptyList(),
                                      null,
                                      false,
                                      false,
                                      true,
                                      true);

        List<ColumnIdentifier> nonRestrictedPrimaryKeyColumns =
            Lists.newArrayList(filter(primaryKeyColumns, name -> !restrictions.isRestricted(table.getColumn(name))));

        if (!nonRestrictedPrimaryKeyColumns.isEmpty())
        {
            throw ire("Primary key columns %s must be restricted with 'IS NOT NULL' or otherwise",
                      join(", ", transform(nonRestrictedPrimaryKeyColumns, ColumnIdentifier::toString)));
        }

        // See CASSANDRA-13798
        Set<ColumnMetadata> restrictedNonPrimaryKeyColumns = restrictions.nonPKRestrictedColumns(false);
        if (!restrictedNonPrimaryKeyColumns.isEmpty() && !MV_ALLOW_FILTERING_NONKEY_COLUMNS_UNSAFE.getBoolean())
        {
            throw ire("Non-primary key columns can only be restricted with 'IS NOT NULL' (got: %s restricted illegally)",
                      join(",", transform(restrictedNonPrimaryKeyColumns, ColumnMetadata::toString)));
        }

        /*
         * Validate WITH params
         */

        attrs.validate();

        if (attrs.hasOption(TableParams.Option.DEFAULT_TIME_TO_LIVE)

View on GitHub (pinned to 88fd0f6a0e)

Solutions

Add 'col IS NOT NULL' for each unrestricted primary key column in the WHERE clause.
Restrict the column with an equality condition instead (e.g. b = 'x').
Remove the column from the view primary key if it should not be restricted.

Example fix

// before
CREATE MATERIALIZED VIEW mv AS SELECT a, b, c FROM t WHERE a IS NOT NULL PRIMARY KEY (a, b, c);
// after
CREATE MATERIALIZED VIEW mv AS SELECT a, b, c FROM t WHERE a IS NOT NULL AND b IS NOT NULL AND c IS NOT NULL PRIMARY KEY (a, b, c);

Defensive patterns

Strategy: validation

Validate before calling

List<String> unrestricted = viewPkColumns.stream()
    .filter(c -> !whereRestricts(c))
    .collect(toList());
if (!unrestricted.isEmpty())
    throw new IllegalArgumentException("add IS NOT NULL for: " + unrestricted);

Prevention

After writing the view PRIMARY KEY, verify each column appears in WHERE (IS NOT NULL or equality).
Regenerate the WHERE clause whenever the view key changes.

When it happens

Trigger: CREATE MATERIALIZED VIEW ... PRIMARY KEY (a, b) WHERE a IS NOT NULL, omitting a restriction (e.g. IS NOT NULL or equality) for column b.

Common situations: Users forget one of several key columns when writing the view WHERE clause, especially after adding columns to the PRIMARY KEY clause.

Understand the failure class

Background: Schema validation failed / invalid input schema: payload rejected because its shape doesn't match the expected schema — this error's family across 28 libraries.

Related errors

AI-assisted analysis of apache/cassandra@88fd0f6a0e (2026-09-10). Data as JSON: /api/errors/14e8e4f1ac895c21. Report an issue: GitHub.