Proposal: Extend IndexContent with size_bytes, created_at, index_details, and more

[wjones127]

ListTableIndices returns IndexContent with only index_name, index_uuid, columns, and status. Consumers needing an index's type, size, or row count had to follow up with one DescribeTableIndexStats call per index — an N+1.

I propose to add the metadata that describe_indices exposes cheaply from the manifest to IndexContent:

Field	Type	Notes
index_type	string	friendly type, e.g. IVF_PQ, BTREE
type_url	string	protobuf type URL
num_indexed_rows	int64	approximate; may include deleted rows
size_bytes	int64, nullable	total across segments; null pre file-size tracking
num_segments	int32	number of index deltas/segments
created_at	date-time, nullable	min across segments; null for legacy indices
index_version	int32	on-disk index format version
index_details	string (opaque JSON), nullable	type-specific details

All fields are optional for backwards compatibility with older servers.

[Xuanwo]

I love this idea.