Query Execution in Column-Oriented Database Systems ppt

... I/O intensive join operators, whereas for CPU intensive join operators, explicitly decompressing all join attributes can avoid prohibitive decompression over- head during join processing. In the ... join in the future and study its im- pact on our techniques. Queries: We are interested in queries (particularly joins) involving compressed string-valued attributes. Although que- ries invo...

Ngày tải lên: 30/03/2014, 13:20

... a query; • Using index-only plans; by creating a collection of indices that cover all of the columns used in a query, it is possible for the database system to answer a query without ever going ... low, which improves query performance. Finally, we introduce a new join technique, the “invisible join”, that converts a join into a set of faster predicate applications on individual co...

Ngày tải lên: 23/03/2014, 16:20

... of the query and combining the results at the peer launching the initial query. This approach ignores RDF/S schema information during query routing, while distributed query planning and execution ... s in acc ordance to best effort query processing strategies for P2P systems introduced in [43]. Moreover, promoting intra-peer processing exploits the benefits of query shipping...

Ngày tải lên: 19/02/2014, 12:20

... for performing inter- polation inside a database system that is similar in spirit to MauveDB, including query language extensions and opti- mizations for efficient operation inside of the database ... handling incomplete information in databases. In PODS, 1989. [16] S. Grumbach, P. Rigaux, and L. Segoufin. Manipulating interpolated data is easier than you thought. In VLDB, 2000. [1...

Ngày tải lên: 30/03/2014, 13:20

... White Plains, N.Y., June 1980. [KOOI82] Kooi, R. and Frankfurth, D., " ;Query Optimization in INGRES," IEEE Database Engineering, September 1982. [LITW80] Litwin, W., "Linear Hashing: ... described in [ONG84]. Our initial experience with the system is that dynamic linking is not preferable to static linking. One problem is that initial loading of routines is slow. Also, t...

Ngày tải lên: 22/10/2013, 10:15

... session requires a chain of database links, each database to be added to the chain will examine all databases in the chain so far. If there is a single database in the chain that cannot be trusted, ... statement terminates the session in the remote database pointed to by the SALES database link: ALTER SESSION CLOSE DATABASE LINK sales; To close a database link connection...

Ngày tải lên: 17/01/2014, 09:20

... an organisation in today’s global e-commerce environment. The network cabling infrastructure must be able to support an enterprise’s increasing rates of data transmission now and in the future. ... this White Paper outlines KRONE’s methodology of testing for, achieving and, indeed, guaranteeing Zero Bit Error Rate. WHAT THE STANDARDS SAY The IEEE 802.3 Standard defines the lowest acceptab...

Ngày tải lên: 19/01/2014, 05:20

... result, the instruction did not match the initial essay quality. Nonetheless, in the open- question interviews, many users indicated using the NM as a reference while updating their essay. In addition ... Q14-16 were included to probe user’s post tutoring perceptions. We find a trend that in the NM problems it was easier for users to under- stand the system’s main point (Q14). Howev...

Ngày tải lên: 20/02/2014, 12:20

... mappings, which have important impli- cations in automatically acquiring and inter- preting user vocabularies for conversational systems. 1 Introduction To facilitate effective human machine ... 2000). These psycholinguistics findings have provided a foundation for our investigation. In research on multimodal interactive systems, re- cent work indicates that the speech and gaze inte- gr...

Ngày tải lên: 20/02/2014, 12:20

... The engineers have their own system will be used to represent both notions. work area for creating, changing, testing, and integrating code. At a certain point, the code is made into a baseline 1.3 ... software engineers who are responsible for developing building of the product in an optimal manner. and maintaining the software product, the tester who • Process management: ensuring the car...

Ngày tải lên: 21/02/2014, 11:20