QUERY PLAN
Group (cost=36.78..44.03 rows=290 width=35)
Group Key: u.pinyin1, u.namecut1, u.pinyin2, u.namecut2, u.pinyin3, u.namecut3, u.pinyin4, u.namecut4, urcl.user_id
-> Sort (cost=36.78..37.51 rows=290 width=35)
Sort Key: u.pinyin1 NULLS FIRST, u.namecut1 NULLS FIRST, u.pinyin2 NULLS FIRST, u.namecut2 NULLS FIRST, u.pinyin3 NULLS FIRST, u.namecut3 NULLS FIRST, u.pinyin4 NULLS FIRST, u.namecut4 NULLS FIRST, urcl.user_id
-> Hash Left Join (cost=18.24..24.92 rows=290 width=35)
Hash Cond: (urcl.user_id = u.id)
-> Seq Scan on tbl_user_role_change_logs urcl (cost=0.00..5.90 rows=290 width=4)
-> Hash (cost=16.44..16.44 rows=144 width=35)
-> Seq Scan on tbl_users u (cost=0.00..16.44 rows=144 width=35)