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SAP HANA Developer Guide - Get a Free Blog

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Stopword<br />

ltd<br />

The stopwords will not be searched, so the resulting search terms would be:<br />

Search Terms<br />

Incredible Busy Machines Ltd<br />

Incredible Busy Machines Limited<br />

IBM Ltd<br />

IBM Limited<br />

Fuzzy Search with Term Mappings<br />

Facts About Term Mappings<br />

Term mappings have the following characteristics:<br />

● Term mappings can be used to extend the search by adding additional search terms to the user input.<br />

Whenever the user enters a search term, the search term is expanded and synonyms, hypernyms, hyponyms,<br />

and so on are added. The result that is returned to the user contains additional records or documents related<br />

to the search term that may be useful to the user.<br />

● Term mappings are defined in a column table and can be changed at any time.<br />

The current term-mapping definition is applied when a search is started. The definition of term mappings<br />

does not change the data that is stored in the database tables (in contrast to the definition of synonyms in<br />

Text Analysis, where a change of synonyms requires a reload or reindexing of the text data).<br />

● Term mappings can be grouped.<br />

Each group of term mappings is identified by a list_id that is stored in the term-mapping table. By grouping<br />

term mappings it is possible to apply different sets of term mappings to different columns of a table. For<br />

example, you may want to use some term mappings when searching company names and other term<br />

mappings when searching documents. When starting a search, it is possible to specify the term-mapping<br />

list_ids that shall be applied to each column.<br />

● Term mappings can be assigned a weight.<br />

In this case, records that are found because of a term mapping will get a lower score than records found with<br />

the original user input. From the user's view, the result list is sorted in a more useful way.<br />

● Term mappings are defined as a unidirectional replacement.<br />

For a term-mapping definition of 'term1' -> 'term2', 'term1' is replaced with 'term2', but 'term2' is not replaced<br />

with 'term1'. This is helpful if you want a search with a hypernym to find all hyponyms, but not the other way<br />

round. If a bidirectional replacement is needed (as for synonyms), both directions have to be added to the<br />

term-mapping table.<br />

<strong>SAP</strong> <strong>HANA</strong> <strong>Developer</strong> <strong>Guide</strong><br />

Enabling Search<br />

P U B L I C<br />

© 2012 <strong>SAP</strong> AG. All rights reserved. 295

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