xBestIndex malfunction

[aizigox-lang]

Sqlite-vector extension only accepts either

• a literal vector blob (X'…'), or
• a scalar sub‑select that returns exactly one vector
  as the 3rd argument to vector_quantize_scan. It does not accept a column reference (base.vec) or a join expression. That’s why all the CTE/column‑based attempts keep failing with xBestIndex malfunction.

[marcobambini]

@aizigox-lang, there is a workaround: you can use a subquery that returns exactly what you need (for example):

SELECT * FROM vector_quantize_scan('images', 'embedding', (SELECT vec FROM base WHERE id = 123), 20)

What do you think?

[aizigox-lang]

Any plans to support multiple vectors at once as 3rd argument. Currenltly I'm doing:

foreach ($filtered as $w) {
			
			$qw = $quote($w);
			$selects[] = "
				SELECT {$qw} AS target, group_concat(w.word) AS ext
				FROM words2 AS w
				JOIN vector_quantize_scan(
					'words2',
					'vec',
					COALESCE(
						(SELECT vec FROM words2 WHERE word = {$qw} LIMIT 1),
						zeroblob(384 * 4)
					),
					10
				) AS v
				ON w.rowid = v.rowid
				WHERE w.word <> {$qw}
			";
		}

		$sql  = implode(' UNION ALL ', $selects);
		$out  = go($sql, 'en');

In the ~150k database it still takes too much time. I have Intel Core I5 that support AVX2 but system shows me CPU. Should it be compiled special way (under Windows)?
Thanks.