Snowflake
Zero-Copy Cloning
Instantly create full database, schema, or table copies without duplicating storage.
Zero-copy cloning lets you create an instant, fully independent copy of a table, schema, or entire database using the CLONE keyword — without physically copying any data. The clone shares the same underlying micro-partitions as the source at the moment of cloning, so the operation completes in seconds regardless of the source's size.
It's like giving someone a symbolic link to your entire file system that only starts consuming extra disk space once they begin editing files — until then, it's free to create.
Key Concepts
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Because micro-partitions are immutable, cloning simply creates new metadata pointers referencing the existing storage. Storage costs only increase when the clone or the source diverges — i.e., when new data is written to either, Snowflake stores only the new/changed micro-partitions, not a full duplicate.
diverges
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This makes cloning extremely valuable for creating dev/test/staging environments from production data, taking instant "snapshots" before risky operations, or spinning up a copy for a data science experiment — all without the storage cost or time delay of a traditional copy.
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Clones can also be combined with Time Travel, letting you clone a table or database as it existed at a past point in time (CREATE TABLE ... CLONE ... AT/BEFORE), which is powerful for reproducing a bug or auditing historical states.
CREATE TABLE ... CLONE ... AT/BEFORE