pgsql: Avoid retrieval of CHECK constraints and DEFAULT exprs in data-o

Avoid retrieval of CHECK constraints and DEFAULT exprs in data-only dump

Those extra queries are not necessary when doing a data-only dump. With
this change, this means that the dependencies between CHECK/DEFAULT and
the parent table are not tracked anymore for a data-only dump. However,
these dependencies are only used for the schema generation and we have
never guaranteed that a dump can be reloaded if a CHECK constraint uses
a custom function whose behavior changes when loading the data, like
when using cross-table references in the CHECK function.

Author: Julien Rouhaud
Reviewed-by: Daniel Gustafsson, Michael Paquier
Discussion: https://postgr.es/m/20200712054850.GA92357@nol

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/5423853feebd30772b7ff9b306885dcb02b79e76

Modified Files
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src/bin/pg_dump/pg_dump.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)