Predicate evaluation is not offloaded to Exadata Cell in the following cases
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A scan is performed on a flashback table.
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A query that has more than 255 columns referenced
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A query that has more than 255 columns referenced and HCC compressed
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The tablespace is encrypted, and the CELL_OFFLOAD_DECRYPTION parameter is set to false
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The tablespace is encrypted, and the CELL_OFFLOAD_DECRYPTION parameter is set to true
Flashback table scans require database-level processing and cannot be offloaded. Queries over 255 columns exceed cell offload capabilities. When CELL_OFFLOAD_DECRYPTION is false on encrypted tablespaces, offload is disabled for security. Option C is redundant - HCC compression doesn't change the 255 column limit. Option E is incorrect - setting CELL_OFFLOAD_DECRYPTION to true enables offload for encrypted data.
On Exadata, Smart Scan predicate filtering (offload) is skipped in several documented cases: when scanning via flashback (accessing prior versions of data), when a query references more than 255 columns of a (non-HCC) table (an internal limit on offloadable column processing), and when the tablespace is encrypted with CELL_OFFLOAD_DECRYPTION set to FALSE — since the cell then lacks the key material to decrypt data locally, the block must be shipped to the DB layer for decryption and filtering instead. Conversely, with CELL_OFFLOAD_DECRYPTION=TRUE, cells can decrypt and still offload the predicate, so that option is correctly marked false. The '>255 columns AND HCC compressed' variant is marked false because the plain '>255 columns' restriction already covers it without needing the HCC qualifier.