Teradata中如何检查数据倾斜
查看空间分布：通过DBC.TableSizeV查询表在各AMP的物理空间分布，计算倾斜度。理想情况下倾斜因子应小于10%。
sql
SELECT TABLENAME, SUM(CURRENTPERM) CURRENTPERM,
CAST((100-(AVG(CURRENTPERM)/MAX(CURRENTPERM)*100)) AS DECIMAL(5,2)) AS SKEWFACTOR_PERCENT
FROM DBC.TABLESIZE
WHERE DATABASENAME = '库名'
GROUP BY 1;
