Search results for "Schema evolution"
showing 2 items of 2 documents
Metadata to Support Data Warehouse Evolution
2009
The focus of this chapter is metadata necessary to support data warehouse evolution. We present the data warehouse framework that is able to track evolution process and adapt data warehouse schemata and data extraction, transformation, and loading (ETL) processes. We discuss the significant part of the framework, the metadata repository that stores information about the data warehouse, logical and physical schemata and their versions. We propose the physical implementation of multiversion data warehouse in a relational DBMS. For each modification of a data warehouse schema, we outline the changes that need to be made to the repository metadata and in the database.
Accelerating data queries on Hadoop framework by using compact data formats
2016
There are massive amounts of data generated from IoT, online transactions, click streams, emails, logs, posts, social networking interactions, sensors, mobile phones and their applications etc. The question is where and how to store these data in order to provide faster data access. Understanding and handling Big Data is a big challenge. The research direction in Big Data projects using Hadoop Technology, MapReduce kind of framework and compact data formats such as RCFile, SequenceFile, ORC, Avro, Parquet shows that only two data formats (Avro and Parquet) support schema evolution and compression in order to utilize less storage space. In this paper, file formats like Avro and Parquet are c…