Re: \d t: ERROR: XX000: cache lookup failed for relation

On Mon, Jun 04, 2018 at 08:01:41PM +0300, Teodor Sigaev wrote:
> >Also note that my "INSERT" was run in a separate loop, concurrent with the
> >VACUUM and ALTER, but yours is running consecutively.
> 
> both loops run in backgound. I tried to run two scripts -  and got a lot of
> deadlocks but not a probem reproduction.

Ah, I think this is the missing, essential component:
CREATE INDEX ON t(right(i::text,1)) WHERE i::text LIKE '%1';

I can reproduce it running just this loop:

time while :; do for a in `seq 999`; do psql postgres --port 5678 -c "ALTER TABLE t ALTER i TYPE int USING i::int";
done;done
 

Justin