data distribution path

基本解释

Without column data-value distribution information in the catalog, DB2 will assume an even distribution of values, which may lead the optimizer to a sub-optimal access path.
如果編目中沒有列數據值分佈信息，DB2 就會假設值是均勻分佈的，這可能導致優化器選擇非最優的訪問路逕。
Without correct column distribution statistics, DB2 may not have enough information to make the best choice when choosing an access path to the data—especially if data is heavily skewed.
在選擇數據的訪問路逕時，如果沒有正確的列分佈統計數據，DB2 可能沒有足夠的信息來做出最佳的選擇，尤其是如果數據出現嚴重誤差。