Inaccurate error message when set fdw batch_size to 0

Hi,

When testing the fdw batch insert, I found a possible issue.

If I set the batch_size to 0 , it will throw an error:

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CREATE FOREIGN TABLE test(a int, b varchar)

  SERVER testserver

  OPTIONS (table_name 'testlocal', batch_size '0');

ERROR:  fetch_size requires a non-negative integer value

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The error message here seems not accurate, because

I can see from the code batch_size should be positive ( > 0).

So, is it better to change the error message to “fetch_size requires a positive integer value” ?

I also found fetch_size has the similar issue, attaching a patch to fix this.

Best regards,

houzj