Paul M Foster wrote:
Scenario: You have to update a record. One or more fields are unchanged
from the original record being altered. So you have two options: 1)
Include those fields in your UPDATE statement, even though they are
unchanged; 2) Omit unchanged fields from the UPDATE statement.
My first inclination is to omit unchanged fields. However, I have the
idea that PG simply marks the existing record to be dropped, and
generates a whole new row by copying unspecified fields from the
original record.
My question is, which is more efficient? Performance-wise, does it
matter whether unchanged fields are included or omitted on UPDATE
statements
my first order guess is, sending and having to parse the additional
unchanged fields in your UPDATE statement is more expensive than letting
the engine just copy them from the old tuple to the new.
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