Never use REQUIRED mode for new nested fields of existing columns#403
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Ian Streeter (istreeter) wants to merge 1 commit intodevelopfrom
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Never use REQUIRED mode for new nested fields of existing columns#403Ian Streeter (istreeter) wants to merge 1 commit intodevelopfrom
REQUIRED mode for new nested fields of existing columns#403Ian Streeter (istreeter) wants to merge 1 commit intodevelopfrom
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Piotr Poniedziałek (pondzix)
approved these changes
Apr 29, 2025
There are edge case tables/schemas in which the loader previously tried to alter the table to add a required nested column to a pre-existing struct column. We saw this error message: ``` message": "Provided Schema does not match Table <redacted>:<redacted>.events. Cannot add required fields to an existing schema. (field: <redacted>.<redacted>) ``` This scenario happens only if a schema has been patched after the loader already created the column; or if the table is manually altered; or other similar mis-uses of schemas. This commit works around the issue by forcing nested columns to be NULLABLE if the parent struct column already exists.
Ian Streeter (istreeter)
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There are edge case tables/schemas in which the loader previously tried to alter the table to add a required nested column to a pre-existing struct column. We saw this error message:
This scenario happens only if a schema has been patched after the loader already created the column; or if the table is manually altered; or other similar mis-uses of schemas.
This commit works around the issue by forcing nested columns to be NULLABLE if the parent struct column already exists.