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Ted Xu commented on CALCITE-2619: --------------------------------- [~julianhyde] sorry for the late reply, I was already working on this issue. However, the change is a bit larger than what I expected. I'd like to raise some more issue before I submit the patch: 1. I think the original verification of charset can only tell a Unicode string is LATIN1 encoded or not, since 'value' of NlsString is a Java String. I would change the 'value' type from String to byte[]. 2. The payload of NlsString is a byte[] but we still need to cache an encoded String to reduce encoding cost. I would also like to have a method 'getValueBytes() : byte[]' if someone need to skip encoding entirely. > Reduce string literal creation cost by removing charset check > ------------------------------------------------------------- > > Key: CALCITE-2619 > URL: https://issues.apache.org/jira/browse/CALCITE-2619 > Project: Calcite > Issue Type: Improvement > Components: core > Reporter: Ted Xu > Assignee: Julian Hyde > Priority: Major > > The cost of creating NlsString is very high, due to its charset check. In > some cases, e.g., expression evaluate because of Partition Prune, the > NlsString creation costs 40%+ of total executor's overhead. > -- This message was sent by Atlassian JIRA (v7.6.3#76005)