Postgres：如何在生成的列中包含权重？

Question

我有以下架构：

CREATE TABLE books (
  title VARCHAR(255),
  subtitle TEXT
);

添加没有权重的生成列工作正常：

ALTER TABLE books ADD COLUMN full_text_search TSVECTOR
  GENERATED ALWAYS AS (to_tsvector('english',
    coalesce(title, '') ||' '||
    coalesce(subtitle, '')
  )) STORED; -- ✅ Working

现在我想增加重量，但它不起作用：

ALTER TABLE books ADD COLUMN full_text_search_weighted TSVECTOR
  GENERATED ALWAYS AS (to_tsvector('english',
    setweight(coalesce(title, ''), 'A') ||' '||
    setweight(coalesce(subtitle, ''), 'B')
  )) STORED; -- ❌ Not working

有没有办法在 postgres 的生成列中包含权重？

复制Link：https://www.db-fiddle.com/f/4jyoMCicNSZpjMt4jFYoz5/1385

Answer 1

阅读 docs 后，我发现 setweight 正在返回 tsvector。我不得不这样修改它：

ALTER TABLE books ADD COLUMN full_text_search_weighted TSVECTOR
  GENERATED ALWAYS AS (
    setweight(to_tsvector('english', coalesce(title, '')), 'A') ||' '||
    setweight(to_tsvector('english', coalesce(subtitle, '')), 'B')
  ) STORED; -- ✅ Working

现在我们可以使用以下查询对结果进行排序：

SELECT ts_rank(full_text_search_weighted , plainto_tsquery('english', 'book')), title, subtitle
  FROM "books"
  WHERE full_text_search_weighted @@ plainto_tsquery('english', 'book')
  ORDER BY ts_rank(full_text_search_weighted , plainto_tsquery('english', 'book')) DESC;

复制link：https://www.db-fiddle.com/f/sffBR96NJtWej9c1Pcfg2H/0

Postgres：如何在生成的列中包含权重？

Postgres: How can I include weights in a generated column?

postgresql

weighted

tsvector

generated-columns