Storage and Protection

Question 1

Micro-partitioning size

Answer 1

Micro-partitions are usually broken into 50-500mb each (prior to compression).

Question 2

Metadata on micro-partitions

Answer 2

• The range of values for columns in the micro-partition
• The number of distinct values
• Properties used for optimization and efficient query processing

Question 3

Common Metadata Fields

Answer 3

• Object Definitions

- Object Properties

Question 4

Object Definition Metadata

Answer 4

• Policies
• External Functions
• View definitions

Question 5

Object Properties Metadata

Answer 5

• Object Name

- Object Column

Question 6

How are metadata fields usually populated?

Answer 6

Using CREATE and ALTER statements for a given object.

Question 7

Stage Types in Snowflake

Answer 7

• External Stages
• User stages
• Table stages
• Internal named stages

Question 8

External Stages

Answer 8

Storage locations outside of Snowflake in another cloud storage location such as AWS/Azure/GCP. This allows for great flexibility for potential web hosting and ELT solutions prior to accessing the data in Snowflake.

Question 9

User stages

Answer 9

Personal storage locations assigned to each user. These stages are unique to the user and are internal to Snowflake.

Question 10

Table stages

Answer 10

Storage locations held/associated with a table object. This is particularly useful when staging and loading data exclusively meant for that table.

Question 11

Internal Named Stage

Answer 11

Basically a custom defined stage internal to Snowflake within a database/schema.

Question 12

File Format

Answer 12

An object within Snowflake that stores format information required to load data into a table from a stage.

Question 13

File Format Benefits

Answer 13

Because it is an object, it can be re-used within other objects/statements like across several different COPY statements.

Question 14

Snowflake Time Travel

Answer 14

Enables accessing historical data at any point within a defined period (90 days max).

Question 15

Snowflake Time Travel benefits

Answer 15

• Restoring data-related objects
• Duplicating/backing up data from key points in the past
• Analyzing data usage/manipulation over specified periods of time

Question 16

Data Retention (with Time Travel) periods by edition?

Answer 16

Standard Edition - 24 hours

Enterprise - 90 days

Question 17

Data Retention Period for Transient and Temporary Objects?

Answer 17

Defaults to 24 hours, regardless of Snowflake edition

This can be altered though

Question 18

Fail Safe

Answer 18

Separate from Time Travel, Fail-safe ensures historical data is protected in the event of a system failure or other event.

Fail-safe is a 7 day period during which any historical data is recoverable by Snowflake. This period immediately starts after the Time Travel retention period ends.

Question 19

Is Fail-safe meant to be used as a back-up solution

Answer 19

No, it is a solution meant for recovery after a system failure or mistake.

Question 20

Can a Snowflake user/customer recover their data themselves with Fail-safe?

Answer 20

No, Snowflake must do this for them.

Question 21

Temporary/Transient Objects in Fail-safe?

Answer 21

Temporary and Transient objects are not recoverable with Fail safe.

Question 22

What Encryption Method/Algo does Snowflake use?

Answer 22

AES-256 bit encryption with a hierarchical key model rooted in a hardware security model.

Question 23

How often are keys rotated & rekeyed in Snowflake?

Answer 23

Keys are retired and rotated every 30 days, retired keys are then only used for decryption until they are destroyed 1 year after their creation. When retired keys are destroyed the data they protected is rekeyed with new keys.