Sha1Agg

Table of Contents



Returns a single SHA-1 hash of all of the values in each group, as a lower case hex string. Useful for detecting changes to a set of documents.

String Sha1Agg(AggregationArray valuesArray)

Ordering

The values are sorted before they are hashed, so the result does not depend on the order in which documents are read. Two groups with the same values produce the same hash.


round-pushpin Hashes the words of each language.
SELECT LanguageId, Sha1Agg(Text) as Hash FROM WordList:Word GROUP BY LanguageId




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SQL :: Aggregate Functions
Aggregate functions compute one value from a group of rows.
SQL :: Avg
Returns the average (arithmetic mean) of the values in each group.
SQL :: Count
Returns the number of values in each group. Count(0) and Count(*) count the documents in each group.
SQL :: CountDistinct
Returns the number of distinct values in each group. Values are compared without regard to case unless caseSensitive is true.
SQL :: Distinct
Removes duplicate rows from the results of a SELECT.
SQL :: Expressions
Literals, operators, comments and variables in KBSQL.
SQL :: GeometricMean
Returns the geometric mean of the values in each group: the nth root of their product. Useful for growth rates and ratios.
SQL :: Group By
Group by collapses a result set into one row per distinct set of values.
SQL :: Keywords
A breakdown of all of the statements and keywords supported by the query processor.