Statistical profile estimation in database systems
ACM Computing Surveys (CSUR)
Index scans using a finite LRU buffer: a validated I/O model
ACM Transactions on Database Systems (TODS)
Efficient assembly for complex objects
SIGMOD '91 Proceedings of the 1991 ACM SIGMOD international conference on Management of data
The art of computer programming, volume 3: (2nd ed.) sorting and searching
The art of computer programming, volume 3: (2nd ed.) sorting and searching
An effective algorithm for parallelizing sort merge joins in the presence of data skew
DPDS '90 Proceedings of the second international symposium on Databases in parallel and distributed systems
Approximating block accesses in database organizations
Communications of the ACM
Analysis and performance of inverted data base structures
Communications of the ACM
Estimating Block Accessses when Attributes are Correlated
VLDB '86 Proceedings of the 12th International Conference on Very Large Data Bases
A Method for Design and Performance Modeling of Client/Server Systems
IEEE Transactions on Software Engineering
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We describe an algorithm for estimating the number of page fetches for a partial or complete scan of a B-tree index. The algorithm obtains estimates for the number of page fetches for an index scan when given the number of tuples selected and the number of LRU buffers currently available. The algorithm has an initial phase that is performed exactly once before any estimates are calculated. This initial phase, involving LRU buffer modeling, requires a scan of all the index entries and calculates the number of page fetches for different buffer sizes. An approximate empirical model is obtained from this data. Subsequently, an inexpensive estimation procedure is called by the query optimizer whenever it needs an estimate of the page fetches for the index scan. This procedure utilizes the empirical model obtained in the initial phase.