Overwriting and Refreshing Tables in Databricks

When reloading data from external sources, you may need to refresh existing tables.

Methods:

1. Drop and recreate:

   spark.sql("DROP TABLE IF EXISTS example.databricks.my_table")
   df.write.saveAsTable("example.databricks.my_table")

2. Overwrite with schema handling:

   df.write.option("overwriteSchema", "true").mode("overwrite").saveAsTable("example.databricks.my_table")

Best Practices:

• Use DROP TABLE for inconsistent or manually edited sources (e.g., spreadsheets).
• Use mergeSchema for additive schema changes.
• Always preview with df.show() before writing.