A common reason is using a partition key with excessive cardinality. On creating a table, users can optionally specify a column as a partition key by which data will be separated. A new file system directory will be created for every key value. This is typically a data management technique, allowing users to cleanly separate data logically in a table. Operations such as DROP PARTITION subsequently allow fast deletion of data subsets. This powerful feature can, however, easily be misused, with users interpreting it as a simple optimization technique for queries.
穆傑塔巴‧哈梅內伊：伊朗新任最高領袖是誰？，这一点在新收录的资料中也有详细论述
ContentsThe Problem Statement，推荐阅读新收录的资料获取更多信息
two x_j are the same, there exists a unique polynomial。业内人士推荐新收录的资料作为进阶阅读