Libraries such as CassIO, LangChain, and LlamaIndex create vector
indexes using Cassandra's StorageAttachedIndex (SAI) class name.
This commit lets ScyllaDB accept these statements without modification.
When a CREATE CUSTOM INDEX statement specifies an SAI class name on a
vector column, ScyllaDB automatically rewrites it to the native
vector_index implementation. Accepted class names (case-insensitive):
- org.apache.cassandra.index.sai.StorageAttachedIndex
- StorageAttachedIndex
- sai
SAI on non-vector columns is rejected with a clear error directing
users to a secondary index instead.
The SAI detection and rewriting logic is extracted into a dedicated
static function (maybe_rewrite_sai_to_vector_index) to keep the
already-long validate_while_executing method manageable.
Multi-column (local index) targets and nonexistent columns are
skipped with continue — the former are treated as filtering columns
by vector_index::check_target(), and the latter are caught later by
vector_index::validate().
Tests that exercise features common to both backends (basic creation,
similarity_function, IF NOT EXISTS, bad options, etc.) now use the
SAI class name with the skip_on_scylla_vnodes fixture so they run
against both ScyllaDB and Cassandra. ScyllaDB-specific tests continue
to use USING 'vector_index' with scylla_only.
80a2e4a0ab
