PDF-Extendible Hashing-A Fast Access Method for Dynamic Files

RONALD FAGIN IBM Research Laboratory JURG NIEVERGELT lnstitut lnformatik NICHOLAS PIPPENGER IBM T J Watson Research Center and H RAYMOND STRONG IBM Research Laboratory Extendible hashing 1 EVOLU. The analysis uses only very basic and intuitively understandable concepts of probability theory and is meant to be accessible even for undergraduates taking their 64257rst algorithms course 1 Introduction dictionary is a data structure for storing a Up to this point the greatest drawback of cuckoo hashing appears to be that there is a polynomially small but practically signicant probability that a failure occurs during the insertion of an item requiring an expensive rehashing of all items in th Control. the file server, reimagined. Presented by Mark Minasi. help@minasi.com. @. mminasi. on twitter. 1. contents copyright 2013 Mark . Minasi. Please do not redistribute, and thanks for respecting my copyrights!. Management. 7. . course. Reminder. Disk. . and RAM. RAID . Levels. Disk. . space. management. Buffering. Heap. . files. Page. . formats. Record. . formats. Today. System . catalogue. Hash-based. CSI 2132. Database I. Exercise 1. Both disks and main memory support direct access to any desired location (page). On average, main memory accesses are faster, of course. What is the other important difference (from the perspective of the time required to access a desired page)?. RONALD FAGIN IBM Research Laboratory JURG NIEVERGELT lnstitut lnformatik NICHOLAS PIPPENGER IBM T. J. Watson Research Center and H. RAYMOND STRONG IBM Research Laboratory Extendible hashing 1. EVOLU Database System Implementation CSE 507. Some slides . adapted from R. . Elmasri. and S. . Navathe. , Fundamentals of Database Systems. , Sixth . Edition, . Pearson. .. And . Silberschatz. , . Korth. Victor Zakhary, . Divyakant. Agrawal, Amr El . Abbadi. 1. The old problem of Caching. Disk. RAM. L. 2. L. 1. Larger. Slower. Cheaper. Smaller. Faster. Expensive. 2. The old problem of Caching. Smaller. Database System Implementation CSE 507. Some slides adapted from R. . Elmasri. and S. . Navathe. , Fundamentals of Database Systems. , Sixth Edition, Pearson.. And . Silberschatz. , . Korth. and . Sudarshan. Plan. I spent the last decade advising on numerous cases where hash tables/functions were used. A few observations on . What data structures I’ve seen implemented and where. What do developers think, were they need help. In static hashing, function . h. maps search-key values to a fixed set of . B. . buckets, that contain a number of (K,V) entries.. . . Problem: d. atabases . grow . (or shrink) . with time. . If initial number of buckets is too small, and file grows, performance will degrade due to too much overflows.. Centriworks. Lunch and Learn. for. we have. HEADQUARTERS IN. TEXAS. . &. FINLAND. we have customers of. ALL SIZES. IN 100 COUNTRIES. we have. CUSTOMERS IN. MANY. INDUSTRIES. ELECTRONICS. SOFTWARE. Dynamic Apex. Enables you to create more flexible applications by providing you the ability to access . sObject. and field metadata descriptions.. Allows you to write dynamic SOQL and SOSL queries and dynamic DML.. Nazanin Nourifard, Elena Pasternak, Maxim Lebedev.. Significance. Static moduli of rocks are usually different from the corresponding dynamic moduli.. The . simultaneous measurement of static and dynamic bulk moduli is rarely reported in .