我必须以不区分大小写的方式对两个字符串执行左连接。
这是区分大小写的(176ms)
SELECT * FROM a LEFT JOIN b ON b.text = a.text
我尝试了一些选项,但速度太慢了。
选项 1 (40000ms)
WITH upper_b AS (
SELECT UPPER(text) FROM b
), upper_a AS (
SELECT UPPER(text) FROM a
)
SELECT * FROM upper_a LEFT JOIN upper_b ON upper_b.text = upper_a.text
选项 2 (60000ms)
SELECT * FROM a LEFT JOIN b ON UPPER(b.text) = UPPER(a.text)