稀疏表与块表结合的多租户共享存储模型

针对传统单稀疏表存储模型存储空间利用率低以及块表存储模型重构租户逻辑关系时连接次数多的问题，提出了稀疏表与块表结合的存储模型.该存储模型中将租户基于SaaS应用服务商提供的逻辑表上定制的属性及自定义的逻辑表中的属性映射到列数合适的稀疏表中存储，而将租户一部分常见数据类型的自定义的属性存储到块表中，以此避免因扩展字段的列数超过稀疏表列数导致的数据迁移问题，最后通过定义查询重写器给出了从租户逻辑SQL请求到物理SQL请求的转换.实验结果表明，该存储模型在存储空间利用率及查询效率上相比传统的稀疏表存储模型都有所提升.

Multi-Tenant Shared Storage Model Combining Sparse Tables and Block Table

Aiming at the low utilization of storage space in traditional single-sparse storage model and the problem of more connections in reconstructing the logical relationship of tenants in the block table storage model, the combination of sparse tables and block table storage model is put forward. In the storage model, the attributes in the logic tables provided by the SaaS providers and the attributes in the custom logical tables are mapped into the corresponding sparse tables and the custom attributes of a part of the tenant common data type are stored in the block table, so as to avoid the problem of data migration caused by the number of extended columns exceeding the number of sparse tables. Finally, the query conversion and query efficiency are optimized through the query rewriter. The experimental results show that the storage model improves storage space utilization and query efficiency compared with the traditional sparse table storage model.