What is the typical micro-partition size before compression?

• A. 50 to 500 MB
• B. 1 to 2 GB
• C. 5 to 10 MB
• D. 2 to 10 GB

Answer: (A)

Micro-partitions are the basic storage unit Snowflake uses to organize data. Before any compression, a typical micro-partition holds about 50 to 500 MB of data. This size is chosen to balance efficient pruning during queries—Snowflake can skip partitions that don’t match filters—while keeping the partition small enough to load, cache, and scan quickly. Data is stored columnar within the partition and then compressed, so the on-disk size after compression is smaller, but the uncompressed size remains in that 50–500 MB range. Sizes much smaller (like 5–10 MB) would increase metadata overhead and reduce pruning efficiency, while sizes in the gigabyte range (1–2 GB or more) would hurt pruning and increase scan costs.