Detect overflows in various numerical aggregate transfns Here we add overflow checks to guard against overflowing the int8 sum of all inputs for sum(int2), sum(int4), avg(int2) and avg(int4). Such an overflow is very unlikely for the int2 versions, but somewhat possible to hit for the int4 versions when given billions of large enough inputs. Since our code and machines are getting faster, and with the advent of things like columnar table AMs, it's getting more likely that such an overflow could occur in a real use case.
No guards have been added to the average count. That would require 2^63 input rows, which is not possible to achieve in a single instance of PostgreSQL, given other limitations such as 64-bit LSNs. Fixing this only in master as we can probably get away with that today due to this still being unlikely for users to ever hit. Author: Andrei Lepikhov <[email protected]> Reviewed-by: David Rowley <[email protected]> Reviewed-by: Tom Lane <[email protected]> Reviewed-by: Chao Li <[email protected]> Discussion: https://postgr.es/m/[email protected] Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/903ce587e665af18ef1af24b4632e5ed4bf78edc Modified Files -------------- src/backend/utils/adt/numeric.c | 38 +++++++++++++++++++++++++++++++++----- 1 file changed, 33 insertions(+), 5 deletions(-)
