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https://issues.apache.org/jira/browse/ASTERIXDB-1606?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15433653#comment-15433653
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Steven Jacobs commented on ASTERIXDB-1606:
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This will be great to have in master. What are your thoughts on (1)?
> 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.
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