Semantic Join

ThalamusDB supports semantic join operators. With semantic joins, you can specify a join condition in natural language. Semantic joins can refer to columns containing text, images, or a mix of both. Use the NLjoin command to define a semantic join condition. ThalamusDB evaluates semantic joins using LLMs.

The NLjoin(C1, C2, P) operator is configured using three parameters:

  • C1 A column in the first table
  • C2 A column in the second table
  • P Join condition in natural language

NLjoin appears in the WHERE clause of the associated query (i.e., not in the FROM clause). Note that NLjoin only specifies the join condition. The joined tables must still appear in the SQL FROM clause of the associated query (without the JOIN keyword).

Here are a few example queries using the semantic join operator:

SELECT H.pic, P.pic
FROM HolidayPictures H, ProfilePictures P
WHERE NLjoin(H.pic, P.pic, 'The two pictures show the same person');

SELECT description, pic
FROM Descriptions, Pictures
WHERE NLjoin(
  description, pic,
  'The description matches the picture');