小编use*_*701的帖子

我有一个包含大约 700 万条记录的表。该表有一个名字和姓氏列，我想使用 levenshtein() 距离函数进行搜索。

select levenshtein('JOHN', first_name) as fn_distance,
       levenshtein('DOE', last_name) as ln_distance,
       id,
       first_name as "firstName",
       last_name as "lastName"
  from person
 where first_name is not null
   and last_name is not null
   and levenshtein('JOHN', first_name) <= 2
   and levenshtein('DOE', last_name) <= 2
 order by 1, 2
 limit 50;

上面的搜索很慢（4 - 5 秒），我可以做些什么来提高性能？应该在两列上创建索引，还是其他什么？

添加以下索引后：

create index first_name_idx on person using gin (first_name gin_trgm_ops);

create index last_name_idx on person using gin(last_name gin_trgm_ops);

查询现在大约需要 11 秒。:(

新查询：

select similarity('JOHN', first_name) as fnsimilarity, …