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Only one of these errors is allowed. Dates with more than one error are not considered similar, so the score is 0.0.
Dates with a score less than the fuzzySimilarity parameter are not returned.
Example:
SELECT TO_DECIMAL(SCORE(),3,2) AS score, * FROM dates
WHERE CONTAINS(dateofbirth, '2000-01-10', FUZZY(0.8))
ORDER BY score DESC;
For this example we get:
2000-01-09 -> 0.00 (not returned to the user)
2000-01-10 -> 1.00
2000-01-11 -> 0.90
2000-01-12 -> 0.90
...
2000-01-21 -> 0.00 (not returned to the user)
...
2000-10-01 -> 0.80
Score Calculation for Date Distance
The maximum allowed distance between dates can be defined using the search option 'maxDateDistance', which
defines a number of days.
The default for this option is 0, that is, the feature is disabled. This is shown in the following example:
SELECT TO_DECIMAL(SCORE(),3,2) AS score, * FROM dates
WHERE CONTAINS(dateofbirth, '2000-01-10', FUZZY(0.95, 'maxDateDistance=5'))
ORDER BY score DESC;
This query returns all dates between 2000-01-05 and 2000-01-15.
The fuzzy score for dates is calculated as follows:
The identical date gets a score of 1.0.
The date that is maxDateDistance days away from the search input gets a score that equals the fuzzySimilarity
parameter (0.95 in the example above).
The score of dates between the identical date and maxDateDistance is calculated as a linear function between the
two dates defined above. In other words, for each day the score is reduced by ((1-fuzzySimilarity) /
maxDateDistance).
For dates outside the range of maxDateDistance, the score is 0.0.
SAP HANA Developer Guide
Enabling Search
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