Characteristics of reader accounts in Snowflake include:
* A. Reader account users cannot add new data to the account: Reader accounts are intended for data consumption only. Users of these accounts can query and analyze the data shared with them but cannot upload or add new data to the account.
* E. Reader accounts enable data consumers to access and query data shared by the provider: One of the primary purposes of reader accounts is to allow data consumers to access and perform queries on the data shared by another Snowflake account, facilitating secure and controlled data sharing.
References:
* Snowflake Documentation: Reader Accounts

The LOGIN_HISTORY view in SNOWFLAKE.ACCOUNT_USAGE shows from which IP address a user connected to Snowflake. This view is particularly useful for auditing and monitoring purposes, as it helps administrators track login attempts, successful logins, and the geographical location of users based on their IP addresses.
Reference to Snowflake documentation on LOGIN_HISTORY:
* Monitoring Login Attempts

Reference: https://docs.snowflake.com/en/user-guide/tables-clustering-keys.html

External functions are user-defined functions that are stored and executed outside of Snowflake.
External functions make it easier to access external API services such as geocoders, machine learning models, and other custom code running outside of Snowflake. This feature eliminates the need to export and reimport data when using third-party services, significantly simplifying your data pipelines.
https://docs.snowflake.com/en/sql-reference/external-functions.html#:~:text=External%20functions%20are%20user%2Ddefined,code%20running%20outside%20of%20Snowflake.