理解database cracking

• Overview

  哈，完全不知道这个概念。

• database cracking

  MonetDB was one of the first database to introduce Database Cracking.

  Database Cracking is an incremental partial indexing and/or sorting of the data. It directly exploits the columnar nature of MonetDB.

  Cracking is a technique that shifts the cost of index maintenance from updates to query processing.

  The query pipeline optimizers are used to massage the query plans to crack and to propagate this information.

  The technique allows for improved access times and self-organized behavior.

• 学术角度

  Database cracking (DBC) provides an adaptive data storage environment that meets the needs of modern applications in business and science, reorganizing data on demand and adapting indexes on the fly, automatically, and collaterally to query processing.

  Database Cracking is an appealing approach to adaptive indexing: on every range-selection query, the data is partitioned using the supplied predicates as pivots.

  The core of database cracking is, thus, pivoted partitioning.

  理解range-predicate&pivoted partitioning in Database

• Index structure

  In database management systems, index structures are used to speed up queries.

  An index can be built on an attribute and stores all existing attribute values and their corresponding physical position within the memory space in which the column resides.

  Database cracking relies on reordering the pyhsical database according to the needs of incoming queries.

  Queries on attributes which are indexed using database cracking trigger such a reordering according to the query conditions. This procedure is based on teh idea that index amintaining should be part of the query processing instead of database updates.

• References

1. Revisiting the Theory and Practice of Database Cracking
2. Database Cracking
3. Database Cracking: Fancy Scan, not Poor Man’s Sort!
4. Database Cracking; David Werner