On 12/09/2014 06:19 PM, Josh Berkus wrote:
On 12/09/2014 09:41 AM, Alvaro Herrera wrote:
The first thing where this matters is tuple descriptor expansion in
parse analysis; at this stage, things such as "*" (in "select *") are
turned into a target list, which must be sorted according to attlognum.
To achieve this I added a new routine to tupledescs,
The two other major cases are:
INSERT INTO table SELECT|VALUES ...
COPY table FROM|TO ...
... although copy should just be a subclass of SELECT.
Question on COPY, though: there's reasons why people would want COPY to
dump in either physical or logical order. If you're doing COPY to
create CSV files for output, then you want the columns in logical order.
If you're doing COPY for pg_dump, then you want them in physical order
for faster dump/reload. So we're almost certainly going to need to have
an option for COPY.
I seriously doubt it, although I could be wrong. Unless someone can show
a significant performance gain from using physical order, which would be
a bit of a surprise to me, I would just stick with logical ordering as
the default.
cheers
andrew
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