unmatched-keys.md
Data being loaded can contain keys that are not part of the table definition. If you are loading into a flex table (or a flexible complex type column), no data is lost. For a table with strongly-defined columns, however, new keys cannot be loaded because the table does not have a place to put them.
This parser emits warnings if it finds new keys and if both of the following are true:
-
The target table is not a flex table.
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The new key is not nested within a flexible complex type column.
New keys are logged in the UDX_EVENTS system table. If a new key is a complex type with nested keys, only the top-level key is logged. When you see a warning about unmatched keys, you can query this table and then use ALTER TABLE to modify your table definition for future loads.
Querying an external table loads data and thus can trigger these warnings. To prevent them, set the suppress_warnings
parameter to 'unmatched_keys' or 'true':