Permanent vs Transient vs Temporary Tables in Snowflake

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Permanent vs Transient vs Temporary Tables in Snowflake

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Permanent vs Transient vs Temporary Tables in Snowflake

Arabinda Mohapatra

Arabinda Mohapatra

Running Kafka streams after dark, diving into genetic code by daylight, and wrestling with Databricks and Tableflow in every spare moment—sleep is optional

🧊 Snowflake Tables Explained: Permanent vs Transient vs Temporary

Understanding table types in Snowflake is critical for cost, recovery, and data lifecycle decisions.

1️⃣ Permanent Table

  • Default table type in Snowflake
  • Best for: Business-critical, long-term data
  • Time Travel: Up to 90 days (based on account/table setting)
  • Fail-safe: ✅ 7 days (Snowflake-managed, non-configurable)
  • Cost: Highest (because of Time Travel + Fail-safe storage)

👉 Use when data must be recoverable and compliance matters.

2️⃣ Transient Table

  • Designed for intermediate or derived data
  • Time Travel: Up to 1 day (can be set to 0)
  • Fail-safe: ❌ Not available
  • Cost: Lower than permanent tables

👉 Ideal for staging, transformations, temporary business logic outputs.

⚠️ Important rule:

If you create a TRANSIENT SCHEMA, all tables created inside it are automatically TRANSIENT (No need to specify TRANSIENT again at table level)
After creation, transient tables cannot be converted to any other table type.

3️⃣ Temporary Table

  • Session-scoped table
  • Automatically dropped when session ends
  • Time Travel: ❌ Not supported
  • Fail-safe: ❌ Not supported
  • Cost: Lowest

⚠️ Temporary Table Naming Conflicts — Quick Notes

  • Temporary tables are session-based but still belong to a database & schema
  • They do NOT follow global name uniqueness rules

You can have:

A temporary table and A permanent/transient table → with the same name in the same schema

⚠️ Risks & Pitfalls

  • DDL or queries may run on the temporary table instead of the real table
  • Can cause unexpected results or data confusion
  • Hard to debug if you forget a temp table exists

👉 Temporary tables override table name resolution in a session

👉 Always use clear naming and drop temp tables when done

Temporary table always takes precedence within the session
It hides any permanent or transient table with the same name
Drop temporary tables explicitly before sessions end.
Make sure that users explicitly log out of sessions that are inactive.

👉 Best for session-level processing, debugging, quick analysis.

📊 Quick Comparison

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🧠 Key Takeaways

  • Permanent → Production & compliance data
  • Transient → Staging & transformation layers
  • Temporary → Short-lived, session-based workloads
  • Transient schema = all tables are transient (cost saver!)


Refer-

https://docs.snowflake.com/en/user-guide/tables-temp-transient


#Snowflake #DataEngineering #CloudData #TimeTravel #FailSafe #CostOptimization #BigData #LinkedInLearning

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