Selinger, P. Griffiths, et al. "Access path selection in a relational database management system."Proceedings of the 1979 ACM SIGMOD international conference on Management of data. 1979. 这算是最经典的查询优化论文了,在各种查询优化论文推荐列表中都包含了这篇论文(比如:Red book,CMU 15-721,CMU15-...
论文笔记:Access Path Selection In A Relation Database Management System 这篇文章是 1979 年由 IBM 发表的。主要介绍了 System-R 系统的查询优化器设计。 二. Processing Of An SQL Statement
P(T):segment中包含有表T的tuple的pages的比例(TCARD(T) / total pages in segment) 索引统计信息: ICARD(I):索引I的NDV(number of distinct key) NINDX(I):索引I的pages数量 这些统计信息保存在 System R的catalog中,创建表和创建索引时初始化这些统计信息。然后通过 UPDATE STATISTICS 命令定期更新它们,任...
Database selection for processing k nearest neighbors queries in distributed environments. C. T. Yu,P. Sharma,W. Meng,Y. Qin. Proceedings of the ACM/IEEE Joint Conference on Digital Libraries (JCDL 2001) . 2001Yu, C.T., Sharma, P., Meng, W., Qin, Y.: Database selection for ...
After constructing the tree, the algorithm applies to any tuple within the database to classify that tuple45. An MLP is a supervised learning approach that utilizes back-propagating techniques. Because there are many layers of neurons in an MLP, it can be considered a deep learning approach ...
Materialized View Selection in a Multidimensional Database Elena Baralis Stefano Paraboschi Ernest Teniente A Practical Example Consider the MDDB for a large grocery store chain, characterized by a large number of stores, each of which is a supermarket selling a wide variety of different product...
Demolombe, R., “Estimation of the number of tuples satisfying a query expressed in predicate calculus language,” in Proc. Intl. Conf on Very Large Databases ,Montreal, Canada,1980, pp. 55–63. Comer, D., “The ubiquitous B-tree,” ACM Trans. Database Systems ,Vol. 11, No. 2,...
This abundance in data is generally used for two purposes: Predicting and understanding; likewise, feature selection has two essential aims: Model improvement and interpretability. Very often, most of the features defining a data point are redundant, irrelevant, or affected by large noise, and have...
2.1.588 Part 4 Section 2.18.88, ST_SignedTwipsMeasure (Signed Measurement in Twentieths of a Point) 2.1.589 Part 4 Section 2.18.91, ST_TabJc (Custom Tab Stop Type) 2.1.590 Part 4 Section 2.18.100, ST_TextDirection (Text Flow Direction) 2.1.591 Part 4 Section 2.18.101, ...
a mathematical function f that is defined on some collection X of nonempty sets and assigns to each set S in that collection some element f(S) of S. There are choice functions that pick such triplets or bigger tuples in some worlds, but there isn't one that does so in all worlds....