Fei Hu created SYSTEMML-1831: -------------------------------- Summary: 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
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)