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Yingyi Bu edited comment on ASTERIXDB-1606 at 8/24/16 5:29 PM: --------------------------------------------------------------- Does any database provide (1)? GREATEST is a function name in most databases, e.g.: https://docs.oracle.com/cd/B19306_01/server.102/b14200/functions060.htm :-) was (Author: buyingyi): Does any database provide (1)? GREATEST is a function name in most database, e.g.: https://docs.oracle.com/cd/B19306_01/server.102/b14200/functions060.htm :-) > Optimize "last value" query > --------------------------- > > Key: ASTERIXDB-1606 > URL: https://issues.apache.org/jira/browse/ASTERIXDB-1606 > Project: Apache AsterixDB > Issue Type: Bug > Reporter: Steven Jacobs > Priority: Minor > > We need to work on optimizing queries looking for a "most recent" or > "greatest" value of a given field. > As an example, consider an append-only dataset filled with user locations > over time, and suppose we want to know the user's last known location. > Currently, we would need to do this as an: > order by $record.timeStamp > limit 1 > We could improve this in two ways: > 1) Improve usability by providing an alias syntax for users, e.g. "where > greatest timeStamp" > 2) Improve the compilation of such a job to only retrieve a single record. -- This message was sent by Atlassian JIRA (v6.3.4#6332)