Database Query Processing Using Finite Cursor Machines [chapter]

Martin Grohe, Yuri Gurevich, Dirk Leinders, Nicole Schweikardt, Jerzy Tyszkiewicz, Jan Van den Bussche
2006 Lecture Notes in Computer Science  
We introduce a new abstract model of database query processing, finite cursor machines, that incorporates certain data streaming aspects. The model describes quite faithfully what happens in so-called "one-pass" and "two-pass query processing". Technically, the model is described in the framework of abstract state machines. Our main results are upper and lower bounds for processing relational algebra queries in this model, specifically, queries of the semijoin fragment of the relational
more » ... Keywords Database · Relational algebra · Semijoin · Query processing Introduction We introduce and analyze finite cursor machines, an abstract model of database query processing. 1 Data elements are viewed as "indivisible" abstract objects with a vocabulary of arbitrary, but fixed, functions. Relational databases consist of finitely many finite relations over the data elements. Relations are considered as tables whose rows 1 The model was first presented in a talk at the ASM 2004 workshop [30] .
doi:10.1007/11965893_20 fatcat:ikkv6o65m5ee7bkoxcgudodqra