Cloud Data Storage Solutions Flashcards

What distinguishes a data lakehouse from a traditional data lake?

Answer: It combines lake-scale storage with warehouse-style management and ACID tables

A lakehouse layers warehouse features like ACID transactions and governance onto low-cost lake storage.

Which storage choice best supports globally distributed, low-latency reads of a content catalog?

Answer: Object storage fronted by a CDN

A CDN caches objects near users worldwide, delivering low-latency reads from object storage origins.

What is the purpose of a manifest or metadata layer in formats like Delta Lake?

Answer: To track which files belong to a table version for consistent reads

The metadata/transaction log records the set of files per snapshot, enabling ACID reads and time travel.

Which scenario most justifies using a cold storage tier?

Answer: Compliance records that must be retained but are rarely accessed

Cold tiers minimize storage cost for infrequently accessed data like long-term compliance archives.

What does 'storage tiering' aim to optimize in a cloud environment?

Answer: The balance between access cost, retrieval latency, and storage price

Tiering matches data to the storage class whose cost and latency fit its access pattern.

Which technique helps a query engine skip files without opening them in a cloud data lake?

Answer: Min/max column statistics and partition pruning

File-level min/max statistics let engines skip files that cannot contain matching rows.

What is a key consideration when choosing block size or file size for analytical cloud storage?

Answer: Balancing parallelism against per-file overhead, often hundreds of MB per file

Moderately large files (e.g., 128 MB–1 GB) balance read parallelism with metadata and open overhead.