[ https://issues.apache.org/jira/browse/CALCITE-2619?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Julian Hyde resolved CALCITE-2619. ---------------------------------- Resolution: Fixed Fix Version/s: 1.18.0 Fixed in [36bd5fb2|http://git-wip-us.apache.org/repos/asf/calcite/commit/36bd5fb2]; thanks for the PR, [~tedxu]! I made some changes to your PR. I changed the two public NlsString constructors to use the same private constructor, made all fields final (so NlsString is now immutable), and obsoleted your ByteString class, using instead a pair of Avatica's ByteString and a Charset in the cache. (Your ByteString had a charset, while Avatica's ByteString only has an array of bytes.) Lastly, I made your cache static; a non-static cache would have been useless. > Reduce string literal creation cost by removing unnecessary 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 > Fix For: 1.18.0 > > > 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)