Index compression in databases

摘要

Systems, methods and computer program products for compression of database indexes are described herein. A system embodiment includes a sequence determiner to scan a database index and to determine a start of a range and end of a range of consistently changing values in one or more index pages of said database index and an index updater to update said database index based on a sequence determined by said sequence determiner, while suspending writing of one or more values that lie within start of said range and end of said range of values. A method embodiment includes scanning an index, determining a pattern of changing values in one or more index pages of said index and selectively updating said index based on said determining step to minimize index insertions. The method embodiment further includes determining a start of a range of values and an end of said range of values in an index page, setting appropriate bits to identify said start of range of values and end of range of values, determining if an entry to be inserted can appended to at the end of said range of values, and compressing said index by suspending writing of one or more values that occur between said start of range of values and said end of range of values.

主权项

1. A method for populating a database index, comprising:
identifying a location in a database index where a row identifier is to be inserted, said row identifier referencing a database row storing an index key value associated with said row identifier; determining a pattern of consistently changing row identifiers in vicinity of said identified location prior to insertion of said row identifier and said index key value at said identified location in said database index, wherein said consistently changing row identifiers follow a consistent arithmetic sequence in response to a change of their corresponding index key values; upon determination that said row identifier to be inserted is located within said pattern of consistently changing row identifiers, suspending inserting said row identifier and said index key value in said database index; and upon determination that said row identifier to be inserted is located outside of said pattern of consistently changing row identifiers, inserting said row identifier and said index key value in said database index, based on said determined pattern of consistently changing row identifiers.