Bug about drop index concurrently

postgres=# explain analyze select * from xxx where a=500;

ERROR:  could not open relation with OID 25989

The structure of my table is as follows:

postgres=# \d xxx

                Table "public.xxx"

 Column |  Type   | Collation | Nullable | Default 

--------+---------+-----------+----------+---------

 a      | integer |           |          | 

 b      | text    |           |          | 

postgres=# select count(*) from xxx;

 count  

--------

 800000

(1 row)

postgres=# select * from xxx limit 3;

 a |                b                 

---+----------------------------------

 1 | 203c51477570aa517cfa317155dcc52c

 2 | b58da31baa5c78fee4642fd398bd5909

 3 | c7c475bf0a3ca2fc2afc4812a4d44c58

I think this is a bug that will affect the user's experience. we need to fix it.

 I have imagined that the logic that detects the  query transaction and

 waits for it to end is implemented on the standby,but this may increase the

log application delay and the delay is exacerbated that cause the master and backup. 

This is not desirable if the query concurrency is large.

All in all, I expect that you can provide a solution that can use drop index concurrently 

without affecting the master-slave delay.

Sincerely look forward to your reply and thanks.

adger