The data view references a field name that is not available in the data source. 数据视图引用了一个在数据源中无效的域名。
If table statistics are not available, then the estimator uses the number of extents occupied by the table to estimate the base cardinality. 如果表统计数据是无效的,那么估计器使用占用的表扩展来估计基本的行集数。