Computing vector distance functions (like vss_inner_product) incorrectly parses the data

[zen0wu]

I'm dumping some raw bytes into a vector column, but when sqlite-vss parses the BLOB into a vector, it checks if it starts with a v\x01 and if so, these two bytes are treated a header.

The problem is, I have some vectors actually do start with this header (as part of the data) and now it fails to parse the data correctly.

sqlite-vss/src/sqlite-vector.cpp

Lines 68 to 76 in 8fc4430

	if (header != VECTOR_BLOB_HEADER_BYTE) {
	*pzErrMsg = "Blob not well-formatted vector blob";
	return nullptr;
	}
	if (type != VECTOR_BLOB_HEADER_TYPE) {
	*pzErrMsg = "Blob type not right";
	return nullptr;
	}

One thing I can do is to prepend the header to every row, but that feels a really bad solution and it would be great if we can fix this.

[asg017]

Try vector_from_raw() instead. The vector_from_blob() function was a poor attempt at a new vector format, but it made things more complex for no reason (like you saw). The vector_form_raw() on the other hand should handle raw blobs correctly (ie 4 bytes per float vectors).

I'll likely deprecate vector_from_blob() in the next release