fig sample -tree with key deleted has been deleted from the -tree if sequential access is always handled through the -treeit would appear that the feed with feedid has been deleted from the table deleting an item from the table in this way is (log noperation while deleting by rewriting the entire file would take (ntime when is millions of recordsthe difference between (log nand (nis significant the same goes for inserting new row or record within the feed table adding one new record to the end of file can be done quicklywithout rewriting the entire file when -tree is used the newly inserted item automatically maintains its sorted position within the file to summarizeb-trees have several characteristics that make them attractive to use in relational databases and for providing access to large quantities or ordered data these properties includeordered sequential access over the key value on (ntime (log ninsert timewhile maintaining the ordering of the items (log ndelete time of items within the -tree if sequential access is handled through the -tree then (log ndelete time is provided for the underlying table as well -trees can be stored in file and -tree nodes can be read on an as needed basis allowing -trees to be larger than available memory -tree index stored in file does not have to be rebuilt each time it is needed in program it is this final point that make -trees and their derivatives so valuable to relational database implementations relational databases need -trees and their derivative implementations to efficiently process join operations while also providing many of the advantages listed above this copy belongs to 'acha