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Re: [HACKERS] Does having a NULL column automatically exclude the table from the tupleDesc cache? - Mailing list pgsql-hackers

From Tom Lane
Subject Re: [HACKERS] Does having a NULL column automatically exclude the table from the tupleDesc cache?
Date
Msg-id 16777.1487179006@sss.pgh.pa.us
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In response to [HACKERS] Does having a NULL column automatically exclude the table from thetupleDesc cache?  (Ryan Murphy <ryanfmurphy@gmail.com>)
Responses Re: [HACKERS] Does having a NULL column automatically exclude thetable from the tupleDesc cache?  (Ryan Murphy <ryanfmurphy@gmail.com>)
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Ryan Murphy <ryanfmurphy@gmail.com> writes:
> My question is this:  HeapTupleNoNulls() is run first to see if there are
> any columns that can be NULL.  It looks like the fetchatt() that uses the
> cache in the tupleDesc can only be used if there are no NULLable columns in
> the table.  Is my understanding correct?

No, that tests whether the particular tuple contains any null fields, not
whether the whole table is declared NOT NULL.
        regards, tom lane

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