Hibernate also provides data query and retrieval facilities. Alternate automated approaches for generating traces using information retrieval methods have been developed. Databases and search engines differ substantially in terms of coverage and retrieval qualities. Computational linguistics is also used for document retrieval and clustering. Automatic image annotation is used to classify images for image retrieval systems. This will require extra methods for traversal and object retrieval. In order to aid in data retrieval, Yahoo! It also extends Microsoft Office with data retrieval addins. This presents problems for information storage and retrieval. There are times when HTTP GET is less suitable even for data retrieval. Brain imaging studies have shown flashbacks activate areas associated with memory retrieval. This approach has its roots in information retrieval and information filtering research. Memory allows us to store information for later retrieval. Working memory serves as an encoding and retrieval processor. Columnar compression achieves a reduction in disk space at the expense of efficiency of retrieval.