Deleting a Blob
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There are four ways to delete a Blob:
- Delete the row containing the Blob. You can use DSQL to execute a
DELETEstatement. - Replace the Blob with a different one. If a Blob column contains a Blob ID, and you modify the column to refer to a different Blob, the Blob referenced by the previously stored Blob ID will be deleted during the next garbage collection.
- Reset to
NULLthe column referring to the Blob, for example, by using DSQL to execute a statement like the following:
UPDATE PROJECT SET PROJ_DESC = NULL WHERE PROJ_ID = 'VBASE'
- The Blob referenced by the previously stored Blob ID will be deleted during the next garbage collection.
- Discard a Blob after it has been created but before it has been associated with a particular column of a table row. Use the
isc_cancel_blob()function:
isc_cancel_blob(status_vector, &blob_handle);