A key element in the data model is the set of statistics gathered about the data contained in the database and stored in the system catalog tables.

数据模型中的关键元素是一组统计信息，该统计信息收集了有关数据库中所包含的数据和系统目录表中所存储的数据的信息。

youdao

Describes each data element within the bulk data store, such as source organization, application support, data summary, index, catalog, or digests.

描述批量数据存储中的每个数据元素，例如源组织、应用程序支持、数据汇总、索引、目录或摘要。

youdao