[ https://issues.apache.org/jira/browse/SYSTEMML-1831?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Fei Hu reassigned SYSTEMML-1831: -------------------------------- Assignee: Fei Hu > Improve the efficiency of matrix subsetting > ------------------------------------------- > > Key: SYSTEMML-1831 > URL: https://issues.apache.org/jira/browse/SYSTEMML-1831 > Project: SystemML > Issue Type: Improvement > Reporter: Fei Hu > Assignee: Fei Hu > > For the {{rangeReIndex}} operation, it needs to read the whole input matrix > into memory first and do the subsetting in the memory. It is not efficient > because it needs to read a lot of unnecessary data, and even out of memory if > the size of input matrix exceeds the available memory. > The plan here is to read the keys in the Hadoop sequence file, and identify > the keys overlapped with the input range index. Then the values specified by > the identified keys will be read. -- This message was sent by Atlassian JIRA (v6.4.14#64029)