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Lars Hofhansl commented on HBASE-9769: -------------------------------------- Interestingly it depends on which column(s) is (are) selected. Some numbers: 4m rows, 5 cols each, 1 cf, 10 bytes values, VERSIONS=1. Everything measured in seconds. Without patch: ||Wildcard||Col 1||Col 2||Col 4||Col 5||Col 2+4|| |6.4|8.5|14.3|14.6|11.1|20.3| With patch sample1: ||Wildcard||Col 1||Col 2||Col 4||Col 5||Col 2+4|| |6.4|8.4|8.9|9.9|6.4|10.0| Variation here was +- 0.2s. So with this patch scanning is 2x faster than without in some cases, and never slower. No special hint needed, beyond declaring VERSIONS correctly. > Improve performance of a Scanner with explicit column list when rows are > small/medium size > ------------------------------------------------------------------------------------------ > > Key: HBASE-9769 > URL: https://issues.apache.org/jira/browse/HBASE-9769 > Project: HBase > Issue Type: Improvement > Components: Scanners > Affects Versions: 0.98.0, 0.94.12, 0.96.0 > Reporter: Vladimir Rodionov > Assignee: Vladimir Rodionov > Attachments: 9769-0.94-sample1.txt, 9769-0.94-sample.txt > > -- This message was sent by Atlassian JIRA (v6.1#6144)