Column-level security in Snowflake is implemented through Role Access Policies. These policies allow administrators to control access to specific columns of a table or view based on the role of the user accessing the data. By applying a role access policy to a column, administrators can ensure that sensitive information remains secure, and only users with the appropriate roles can view or query the data in that column. This feature enhances the security model by providing fine-grained access control at the column level.
References:
Snowflake Documentation: Implementing Column-level Security

The COPY INTO command in Snowflake can be configured to output data into a single file by setting the MAX_FILE_NUMBER option to 1. This option limits the number of files generated by the command, ensuring that only one file is created regardless of the amount of data being exported.
References:
[ COF-C03 ] SnowPro Core Certification Exam Study Guide
Snowflake Documentation on Data Unloading

To reduce data spilling in Snowflake, using a larger virtual warehouse is effective because it provides more memory and local disk space, whichcan accommodate larger data operations and minimize the need to spill data to disk or remote storage1. References: [COF-C03] SnowPro Core Certification Exam Study Guide

The bulk data load history available after a COPY statement is stored in the metadata of the pipe and is retained for 64 days1.

Snowflake's architecture is described as a multi-cluster, shared data architecture. This design combines the simplicity of a shared-disk architecture with the performance and scale-out benefits of a shared-nothing architecture, using a central repository accessiblefrom all compute nodes2.
References = [ COF-C03 ] SnowPro Core Certification Exam Study Guide, Snowflake Documentation