Sorenson-dice coefficient in a set-based style. Note -- this is an excerpt and probably does not compile, but may be adapted to your use case. This example is implemented in T-SQL (MS SQL Server)

sorenson_dice.sql

SET ANSI_NULLS, QUOTED_IDENTIFIER ON;
GO

/***********************************************************************************************************************
Author:       Nick Reilingh, Fisher Center at Bard College
Description:  Preload for sorensen_dice coefficient word pairs on names.

Notes:
  - This procedure is called from LP_FZM_PRELOAD, which supplies it with a dataset_no parameter
  - It is supplied with dataset parameter from this procedure.
  - This procedure populates a temp table with letter pairs for a dataset to be matched against later.
***********************************************************************************************************************/
CREATE OR ALTER PROCEDURE [fzm].[sorensen_dice_names_PRELOAD]
  @dataset_no int = NULL
AS

WITH numbers AS (
  SELECT
      number
    FROM master.dbo.spt_values
    WHERE type = 'P' AND number < 100
), loading_names AS (
  SELECT
      n.customer_no,
      name = ISNULL(NULLIF(n.fname, '') + ' ', '') + ISNULL(n.lname, ''),
      name_no = ROW_NUMBER() OVER (PARTITION BY n.customer_no ORDER BY (SELECT 1))
    FROM dbo.LS_FZM_NAME n
), wordboundaries AS (
  SELECT
      n.customer_no,
      n.name_no,
      n.name,
      a.word
    FROM loading_names n
      CROSS APPLY (
        SELECT
            word = RTRIM(SUBSTRING(n.name, number + 1, PATINDEX('%[ ][^ ]%', RIGHT(n.name + ' $', DATALENGTH(n.name) + 1 - number))))
          FROM numbers
          WHERE number <= DATALENGTH(n.name)
            AND PATINDEX('[ ][^ ]%', RIGHT(' ' + n.name, DATALENGTH(n.name) + 1 - number)) = 1
      ) a
), wordpairs AS (
  SELECT
      w.customer_no,
      w.name_no,
      w.name,
      a.letterpair
    FROM wordboundaries w
      CROSS APPLY (
        SELECT
            letterpair = SUBSTRING(w.word, number + 1, 2)
          FROM numbers
          WHERE number < DATALENGTH(w.word) - 1
      ) a
), letterpairs_enumerated AS (
  SELECT
      p.customer_no,
      p.name_no,
      p.name,
      p.letterpair,
      letteridx = ROW_NUMBER() OVER (PARTITION BY customer_no, name_no, letterpair ORDER BY (SELECT 1)),
      paircount = COUNT(1) OVER (PARTITION BY customer_no, name_no)
    FROM wordpairs p
)
INSERT tempdb.dbo.[fzm_sorensen_dice_names_tess_letterpairs]
SELECT * FROM letterpairs_enumerated;

GO

/***********************************************************************************************************************
Author:       Nick Reilingh, Fisher Center at Bard College
Description:  Calculates sorensen_dice coefficient. Requires running Preload procedure in the same session.

***********************************************************************************************************************/
CREATE OR ALTER FUNCTION [fzm].[sorensen_dice_names](
  @dataset_no int,
  @primary_id varchar(16)
)
RETURNS TABLE AS RETURN
WITH numbers AS (
  SELECT
      number
    FROM master.dbo.spt_values
    WHERE type = 'P' AND number < 100
), primary_id_names AS (
  SELECT
      name = ISNULL(NULLIF(n.fname, '') + ' ', '') + ISNULL(lname, ''),
      name_no = ROW_NUMBER() OVER (ORDER BY (SELECT 1))
    FROM dbo.LS_FZM_NAME_INPUT n
    WHERE n.dataset_no = @dataset_no
      AND n.primary_id = @primary_id
), wordboundaries AS (
  SELECT
      n.name_no,
      a.word
    FROM primary_id_names n
      CROSS APPLY (
        SELECT
            word = RTRIM(SUBSTRING(n.name, number + 1, PATINDEX('%[ ][^ ]%', RIGHT(n.name + ' $', DATALENGTH(n.name) + 1 - number))))
          FROM numbers
          WHERE number <= DATALENGTH(n.name)
            AND PATINDEX('[ ][^ ]%', RIGHT(' ' + n.name, DATALENGTH(n.name) + 1 - number)) = 1
      ) a
), wordpairs AS (
  SELECT
      w.name_no,
      a.letterpair
    FROM wordboundaries w
      CROSS APPLY (
        SELECT
            letterpair = SUBSTRING(w.word, number + 1, 2)
          FROM numbers
          WHERE number < DATALENGTH(w.word) - 1
      ) a
), letterpairs_enumerated AS (
  SELECT
      p.name_no,
      p.letterpair,
      letteridx = ROW_NUMBER() OVER (PARTITION BY name_no, letterpair ORDER BY (SELECT 1)),
      paircount = COUNT(1) OVER (PARTITION BY name_no)
    FROM wordpairs p
), scored AS (
  SELECT DISTINCT
      t.customer_no,
      score = 200.0 * (COUNT(1) OVER (PARTITION BY t.customer_no, t.name_no, i.name_no)) / (t.paircount + i.paircount),
      t.name
    FROM tempdb.dbo.[fzm_sorensen_dice_names_tess_letterpairs] t
      JOIN letterpairs_enumerated i
        ON t.letterpair = i.letterpair
          AND t.letteridx = i.letteridx
), ordered AS (
  SELECT
      customer_no,
      score = CAST(ROUND(score, 0) AS int),
      criteria = name,
      [order] = ROW_NUMBER() OVER (PARTITION BY customer_no ORDER BY score DESC)
    FROM scored
    WHERE score >= 45
)
SELECT
    customer_no,
    score,
    criteria
  FROM ordered WHERE [order] = 1;
GO