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Assuming a 90-day Time Travel retention period, you should expect your storage
costs to increase by roughly 10 to 20 percent. Note that your DML profile may cause this
ballpark figure to be wildly exceeded. As always, test before implementing Time Travel.
The type of table you choose will affect your storage costs for Time Travel and
Fail-Safe.
Retained micro-partitions are used for the following:
•
Time Travel
•
Fail-Safe
•
Secure Direct Data Shares
•
Private Listings
•
Snowflake Marketplace
•
Replication
•
Cloning
•
Disaster recovery
I cover these subjects in great detail in Maturing the Snowflake Data Cloud.
Immutable micro-partitions do have some downsides. High-frequency, low-volume
DML operations affecting multiple micro-partitions will result in micro-partition churn
and increased data storage costs. You can also experience object locking and SQL
statement queueing, which are clear indicators of performance bottlenecks.
In an extreme example, I recently experienced a table containing 2.5-billion rows
having all micro-partitions rewritten over a four-hour period; hence, the Time Travel
setting was one day representing the minimum period possible. Depending on your
requirements, Snowflake has further provisioned an Automatic Clustering service, which
may mitigate against micro-partition fragmentation, which I discuss later in this chapter.
ChaPTer 4
MiCro-ParTiTionS