each of whom has a unique student ID number. A typical database would use the student ID number as the key; however, one might also reasonably want to be able to look up students by last name. To do this, one would construct a secondary index in which...
3) Index Database 索引数据库 1. Design and Implement of Search Engine Index Database in a Internet; Internet搜索引擎索引数据库的设计与实现 2. In a full-text search system,the setting-up of the index database of full text is a systematic foundation. 在一个全文检索系统中,全文索引数据...
一. Secondary Index(二级索引) 1.1. Secondary Index介绍 • Clustered Index(聚集索引) ◦ 叶子节点存储所有记录(all row data) • Secondary Index(二级索引) ◦ 也可以称为 非聚集索引 ◦ 叶子节点存储的是 索引 和 主键 信息 ◦ 在找到索引后,得到对应的主键,再 回到聚集索引 中找主键对应的记录...
partition table例子,图源自《Database System Concepts》 Local Index: an index built on tuples stored in a particular node; typically, such an index would be built on all the partitions of a given relation. The index contents are stored on the same node as the data. Global Index: an index...
The secondary key index provides predictable and fast access to multiple rows of information in a database.
When to use a secondary index In analyzing application requirements, if more than one candidate exists for the sequence field of a segment, use a secondary index. Choose one sequence field to be defined in the physical DBD. Then set up a secondary index to allow processing of the same segme...
If an attempt is made to store an entity having the same secondary key value as another existing entity, a DatabaseException will be thrown. Because the secondary key is unique, it is useful to lookup entities by secondary key using EntityIndex.get(K). For example: Employee employee = ...
Manolopoulos, Y., Theodoridis, Y., Tsotras, V.J. (2017). Secondary Index. In: Liu, L., Özsu, M. (eds) Encyclopedia of Database Systems. Springer, New York, NY. https://doi.org/10.1007/978-1-4899-7993-3_758-2 Download citation ...
The invention discloses an in-memory database based device and method for constructing and querying an HBase (Hadoop database) secondary index. The device comprises 1) a client, 2) a data processing module and 3) a secondary index module, wherein the client is used for sending out a ...
Instead of building a complete index that stores every single entry in the key columns, HERMIT navigates any incoming key access queries to an existing index built on the correlated columns. This is achieved through the Tiered Regression Search Tree (TRS-Tree), a succinct, ML-enhanced data ...