SAP HANA Developer Guide - Get a Free Blog

2. Perform the search on two columns.
SELECT SCORE() AS score, * FROM companies2
WHERE CONTAINS(companyname, 'IBM',
FUZZY(0.7,'textSearch=compare,bestMatchingTokenWeight=0.7'))
AND CONTAINS(contact, 'Master',
FUZZY(0.7,'textSearch=compare,bestMatchingTokenWeight=0.7'))
ORDER BY score DESC;
SCORE ID COMPANYNAME CONTACT
0.91 6 IBM Corp M. Master
3. Perform a freestyle search.
SELECT SCORE() AS score, * FROM companies2
WHERE CONTAINS((companyname,contact), 'IBM Master', FUZZY(0.7))
ORDER BY score DESC;
SCORE ID COMPANYNAME CONTACT
0.8 6 IBM Corp M. Master
Note: Freestyle search always uses TF/IDF to calculate the score and does not support parameters
such as 'textSearch=compare' or 'bestMatchingTokenWeight=0.7' that influence score calculation.
Therefore, we get a different score for the same record.
Fuzzy Search on String Columns
String types support a basic fuzzy string search. The values of a column are compared with the user input using
the fault-tolerant fuzzy string comparison.
When working with string types, the fuzzy string compare always compares the full strings. When, for example,
searching with 'SAP', a record such as 'SAP Deutschland AG & Co. KG' gets a very low score, because only a very
small part of the string is equal (3 of 27 characters match).
A fuzzy search on string types is a replacement for a non-fault-tolerant SQL statement such as
SELECT ... FROM products WHERE product_name = 'coffe krisp biscuit' ...
that would not return any results because of the spelling errors.
Supported SQL data types are VARCHAR and NVARCHAR.
It is possible to speed up the fuzzy search by creating additional data structures called 'fuzzy search indexes',
which are used for a faster calculation of the fuzzy score. These indexes exist in the memory only, so no additional
disk space is needed.
To get the best response times possible, you should enable the fuzzy search indexes for all database columns that
have a high load of fuzzy searches and for all database columns that are used in performance-critical queries.
SAP HANA Developer Guide
Enabling Search
P U B L I C
© 2012 SAP AG. All rights reserved. 271