diff options
Diffstat (limited to 'src/backend/utils/adt/numeric.c')
| -rw-r--r-- | src/backend/utils/adt/numeric.c | 35 |
1 files changed, 17 insertions, 18 deletions
diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c index 553e261ed00..eea42398541 100644 --- a/src/backend/utils/adt/numeric.c +++ b/src/backend/utils/adt/numeric.c @@ -5172,11 +5172,21 @@ numeric_stddev_internal(NumericAggState *state, vsumX, vsumX2, vNminus1; - const NumericVar *comp; + int64 totCount; int rscale; - /* Deal with empty input and NaN-input cases */ - if (state == NULL || (state->N + state->NaNcount) == 0) + /* + * Sample stddev and variance are undefined when N <= 1; population stddev + * is undefined when N == 0. Return NULL in either case (note that NaNs + * count as normal inputs for this purpose). + */ + if (state == NULL || (totCount = state->N + state->NaNcount) == 0) + { + *is_null = true; + return NULL; + } + + if (sample && totCount <= 1) { *is_null = true; return NULL; @@ -5184,9 +5194,13 @@ numeric_stddev_internal(NumericAggState *state, *is_null = false; + /* + * Deal with NaN inputs. + */ if (state->NaNcount > 0) return make_result(&const_nan); + /* OK, normal calculation applies */ init_var(&vN); init_var(&vsumX); init_var(&vsumX2); @@ -5195,21 +5209,6 @@ numeric_stddev_internal(NumericAggState *state, accum_sum_final(&(state->sumX), &vsumX); accum_sum_final(&(state->sumX2), &vsumX2); - /* - * Sample stddev and variance are undefined when N <= 1; population stddev - * is undefined when N == 0. Return NULL in either case. - */ - if (sample) - comp = &const_one; - else - comp = &const_zero; - - if (cmp_var(&vN, comp) <= 0) - { - *is_null = true; - return NULL; - } - init_var(&vNminus1); sub_var(&vN, &const_one, &vNminus1); |