diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c index b485415975..40b5c0bbdd 100644 --- a/src/backend/utils/adt/numeric.c +++ b/src/backend/utils/adt/numeric.c @@ -8050,9 +8050,13 @@ power_var(NumericVar *base, NumericVar *exp, NumericVar *result) */ ln_dweight = estimate_ln_dweight(base); + /* + * Set the scale for the low-precision calculation, computing ln(base) to + * around 8 significant digits. Note that ln_dweight may be as small as + * -SHRT_MAX, so the scale may exceed NUMERIC_MAX_DISPLAY_SCALE here. + */ local_rscale = 8 - ln_dweight; local_rscale = Max(local_rscale, NUMERIC_MIN_DISPLAY_SCALE); - local_rscale = Min(local_rscale, NUMERIC_MAX_DISPLAY_SCALE); ln_var(base, &ln_base, local_rscale); diff --git a/src/test/regress/expected/numeric.out b/src/test/regress/expected/numeric.out index bd5c774229..7169e0cea0 100644 --- a/src/test/regress/expected/numeric.out +++ b/src/test/regress/expected/numeric.out @@ -1606,6 +1606,12 @@ select coalesce(nullif(0.9999999999 ^ 23300000000000, 0), 0) as rounds_to_zero; 0 (1 row) +select round(((1 - 1.500012345678e-1000) ^ 1.45e1003) * 1e1000); + round +---------------------------------------------------------- + 25218976308958387188077465658068501556514992509509282366 +(1 row) + -- cases that used to error out select 0.12 ^ (-25); ?column? diff --git a/src/test/regress/sql/numeric.sql b/src/test/regress/sql/numeric.sql index 316e46df33..52e56632e0 100644 --- a/src/test/regress/sql/numeric.sql +++ b/src/test/regress/sql/numeric.sql @@ -899,6 +899,7 @@ select 1.2 ^ 345; select 0.12 ^ (-20); select 1.000000000123 ^ (-2147483648); select coalesce(nullif(0.9999999999 ^ 23300000000000, 0), 0) as rounds_to_zero; +select round(((1 - 1.500012345678e-1000) ^ 1.45e1003) * 1e1000); -- cases that used to error out select 0.12 ^ (-25);