Root cause: Use default 'now'::timestamp will not generate timestamp for each transaction,
PG will convert now to a timestamp as soon as the constant is parsed. To fix it, update it
to defult CURRENT_TIMESTAMP, thie setting is the same as default now(), which returns the
start time of current transaction because ther are fuction calls, hey will give the desired
behavior of defaulting to the time of row insertion.
Reference: https://www.postgresql.org/docs/9.6/static/functions-datetime.html#FUNCTIONS-DATETIME-CURRENT
PG version: 9.6.9
This commit is to enable data migrator to support migrates data
from mysql to pgsql, this is a specific step for user to upgrade
harbor across v1.5.0, as we have move harbor DB to pgsql from
1.5.0. It supports both harbor and notary db data migration,
and be split into two steps with dependency.
It also fix issue #4847, add build DB migrator in make process.
