UUID storage in MySQL


You can store a UUID safely as a “Binary 16”, instead of a “Varchar 36”.

If you still require a human-readable column, its possible to use a “generated” column (from MySQL 5.7 and up):

Source: https://mysqlserverteam.com/storing-uuid-values-in-mysql-tables/

additional info for MySQL 8.0 – https://mysqlserverteam.com/mysql-8-0-uuid-support/

Retrieve the DNS TTL values

$ dig +nocmd +noall +answer example.com
example.com. 7139 IN A

Note: If your default DNS server is not the authoritative server for the zone you are digging dig will show the time remaining (until the next refresh) instead of the raw TTL value in this position.

You can work around this by directing dig to specifically use one of the domain’s servers, for example I know that a.iana-servers.net is authoritative for this domain:

$ dig +nocmd +noall +answer @a.iana-servers.net example.com
example.com. 86400 IN A