I updated the patch added to CF 2012-Next [1]. Attached is the updated version of the patch.
For the discussion in [2], I've introduced a new generic option, validate for file_fdw foreign tables, which specifies if file_fdw verifies that tuples meet NOT NULL constraints. The default value for the option is 'false', and if the value is set to 'true', then file_fdw verifies NOT NULL constraints. For example, a user can issue the following to let file_fdw verify the constraint of the msg column. CREATE FOREIGN TABLE ft (id INTEGER, msg TEXT NOT NULL) SERVER fs OPTIONS (filename '/path/to/file', format 'csv', delimiter ',', validate 'true'); At the SELECT time, ABORT is issued when a NOT NULL violation error has been found, like COPY FROM. Once the validation is done successfully using e.g. SELECT COUNT(*), the user can set the option to 'false' using ALTER FOREIGN TABLE. I think this option is needed for flat files due to their lack of ability to check such a constraint. (I added NOT NULL checking to ileIterateForeignScan(), but not to file_acquire_sample_rows(). Should we do that at file_acquire_sample_rows()? I think it is good to just recommend that users do ANALYZE a foreign table after the validation.) For the discussion in [3], I've added a new external function ExecNotNullCheck() and call it from fileIterateForeignScan. Any comments are welcome. Best regards, Etsuro Fujita [1] https://commitfest.postgresql.org/action/patch_view?id=822 [2] http://archives.postgresql.org/message-id/1038.1331738...@sss.pgh.pa.us [3] http://archives.postgresql.org/pgsql-hackers/2012-03/msg00809.php
file_fdw_notnull_v2.patch
Description: Binary data
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