QN : Introduction to Azure Data Lake Storage Gen2

• data lake : repository of data stored in natural format as blobs or files.

• Azure Data Lake Storage is a comprehensive, massively scalable, secure, and cost-effective data lake solution for high performance analytics built into Azure.

• ADLS is optimized for analytical workloads; High data volumes supported to stream and batch solutions.

• ADLS exposes data (file hierarichical system) through API endpoints making it accesible through modern compute technologies e Microsoft Databricks.

• ADLS uses layered access control model :

  • Azure Role based Access Control : read and write access
  • Azure Attribute-based access control (Azure ABAC) : role assignments
  • Access control lists (ACLs) : File level control Permissions aren't automatically inherited from parent directories after a child item is created. However, you can configure default permissions on a parent directory, which are then applied to new child items at the time they're created.

• Data Processing requires less computational resources since data is stored in directories and sub-directories like a file system.

• Data Redundancy : Data Lake Storage inherits all Azure Blob Storage replication models.

• Locally redundant storage (LRS) keeps multiple copies within a single data center

• Zone-redundant storage (ZRS) replicates data across availability zones in the same region.

• Geo-redundant storage (GRS) or read-access geo-redundant storage (RA-GRS) replicates data to a secondary region.

• Geo-zone-redundant storage (GZRS or RA-GZRS) combines zone and geographic redundancy.