Is your feature request related to a problem? Please describe.

CREATE TABLE t(x TIMESTAMP(6)) should work

See: https://www.postgresql.org/docs/11/static/datatype-datetime.html#DATATYPE-TIMEZONES

time, timestamp, and interval accept an optional precision value p which specifies the number of fractional digits retained in the seconds field. By default, there is no explicit bound on precision. The allowed range of p is from 0 to 6.

Describe the solution you'd like

MVP: An optional precision of 6 should be recognized and ignored (this is the default in CockroachDB)

Optionally: support for other precisions than 6.

Workaround

If the desired precision is 6, then the precision can be omitted altogether to obtain equivalent behavior.