Organization of Records in Files Heap-record can be placed anywhere in the file where there is space ■ Sequential-store records in sequential order,based on the value of the search key of each record ■ In a multitable clustering file organization records of several different relations can be stored in the same file Motivation:store related records on the same block to minimize 1/O B+-tree file organization Ordered storage even with inserts/deletes More on this in Chapter 14 Hashing-a hash function computed on search key;the result specifies in which block of the file the record should be placed More on this in Chapter 14 Database System Concepts-7th Edition 13.10 ©Silberscha乜，Korth and SudarshanDatabase System Concepts - 7 13.10 ©Silberschatz, Korth and Sudarshan th Edition Organization of Records in Files ▪ Heap – record can be placed anywhere in the file where there is space ▪ Sequential – store records in sequential order, based on the value of the search key of each record ▪ In a multitable clustering file organization records of several different relations can be stored in the same file • Motivation: store related records on the same block to minimize I/O ▪ B+ -tree file organization • Ordered storage even with inserts/deletes • More on this in Chapter 14 ▪ Hashing – a hash function computed on search key; the result specifies in which block of the file the record should be placed • More on this in Chapter 14