Aggregate

STDDEV_SAMP

Snowflake

Menghitung sample standard deviation dari nilai numerik. Menggunakan N-1 sebagai pembagi (Bessel's correction).

Tipe hasil: FLOATDiperbarui: 6 Jan 2026

Syntax

SQL

STDDEV_SAMP(expression)

Parameter

expressionnumericwajib

Kolom atau ekspresi numerik

Contoh Penggunaan

Sample Standard Deviation

SQL

1 SELECT
2   department,
3   COUNT(*) as sample_size,
4   ROUND(STDDEV_SAMP(salary), 2) as salary_stddev
5 FROM employee_survey
6 GROUP BY department;

Survey karyawan adalah sample, bukan populasi lengkap, jadi gunakan STDDEV_SAMP.

Hasil

DEPARTMENT	SAMPLE_SIZE	SALARY_STDDEV
Engineering	50	25000.00
Marketing	30	18500.00
Sales	45	22000.00

Quality Control dengan Stddev

SQL

1 SELECT
2   batch_id,
3   AVG(weight) as avg_weight,
4   STDDEV_SAMP(weight) as weight_stddev,
5   CASE
6     WHEN STDDEV_SAMP(weight) > 5 THEN 'HIGH_VARIANCE'
7     WHEN STDDEV_SAMP(weight) > 2 THEN 'MODERATE'
8     ELSE 'LOW_VARIANCE'
9   END as quality_flag
10 FROM production_samples
11 GROUP BY batch_id;

Menggunakan sample stddev untuk quality control dalam manufacturing.

Hasil

BATCH_ID	AVG_WEIGHT	WEIGHT_STDDEV	QUALITY_FLAG
B001	100.5	1.2	LOW_VARIANCE
B002	99.8	6.5	HIGH_VARIANCE

Fungsi Terkait

STDDEVSTDDEV_POPVARIANCEVAR_POPVAR_SAMPCORRCOVAR_POPCOVAR_SAMPPERCENTILE_CONTPERCENTILE_DISCMEDIANMODE

Kembali ke Snowflake Functions

1	SELECT
2	department,
3	COUNT(*) as sample_size,
4	ROUND(STDDEV_SAMP(salary), 2) as salary_stddev
5	FROM employee_survey
6	GROUP BY department;

1	SELECT
2	batch_id,
3	AVG(weight) as avg_weight,
4	STDDEV_SAMP(weight) as weight_stddev,
5	CASE
6	WHEN STDDEV_SAMP(weight) > 5 THEN 'HIGH_VARIANCE'
7	WHEN STDDEV_SAMP(weight) > 2 THEN 'MODERATE'
8	ELSE 'LOW_VARIANCE'
9	END as quality_flag
10	FROM production_samples
11	GROUP BY batch_id;