[ https://issues.apache.org/jira/browse/FLINK-2144?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15350396#comment-15350396 ]
Wenlong Lyu commented on FLINK-2144: ------------------------------------ we also consider increment agg for sliding window currently, evicting window must re-compute all the data of the window, no reducing state mechanism is available. > Incremental count, average, and variance for windows > ---------------------------------------------------- > > Key: FLINK-2144 > URL: https://issues.apache.org/jira/browse/FLINK-2144 > Project: Flink > Issue Type: New Feature > Components: Streaming > Reporter: Gabor Gevay > Priority: Minor > Labels: statistics > > By count I mean the number of elements in the window. > These can be implemented very efficiently building on FLINK-2143: > Store: O(1) > Evict: O(1) > emitWindow: O(1) -- This message was sent by Atlassian JIRA (v6.3.4#6332)