stats_extended unexpectedly became a reserved word

[yejr]

Bug Report

$ tiup playground v6.1.2 --db 2 --pd 3 --kv 3 --tiflash 2

$ tiup client ...

my:root@127.0.0.1:4000=> select 1,'stats_extended' as stats_extended from dual;
error: mysql: 1064: You have an error in your SQL syntax; check the manual that corresponds to your TiDB version for the right syntax to use line 1 column 44 near "stats_extended from dual;"

my:root@127.0.0.1:4000=> select 1,'stats_extended' as `stats_extended` from dual;
 1 | stats_extended
---+----------------
 1 | stats_extended
(1 row)

my:root@127.0.0.1:4000=> select * from mysql.stats_extended limit 10;
(0 rows)

my:root@127.0.0.1:4000=> use mysql;
USE

my:root@127.0.0.1:4000=> select * from stats_extended limit 10;
error: mysql: 1064: You have an error in your SQL syntax; check the manual that corresponds to your TiDB version for the right syntax to use line 1 column 29 near "stats_extended limit 10;"

[CbcWestwolf]

/assign

[CbcWestwolf]

/unassign

[isabella0428]

After examining the code, I think they reserve "stats_extended" on purpose. It also applies to "CURRENT_ROLE", "INTERSECT" and "TABLESAMPLE", in order to avoid parser conflict.

It is also listed as reserved keyword in the doc:
https://docs.pingcap.com/tidb/dev/keywords#S:~:text=STATS_COL_LIST-,STATS_EXTENDED%20(R),-STATS_HEALTHY%20(R)

[bb7133]

Hi @time-and-fate , are you still working on this issue?