[ https://issues.apache.org/jira/browse/IMPALA-4192?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16568546#comment-16568546 ]
Michael Ho commented on IMPALA-4192: ------------------------------------ Some initial steps were done in this patch: https://github.com/apache/impala/commit/b38d9826d7ef9bc0ecff548626d30690f935e9c3 > Pull all expressions in a fragment into RuntimeState > ---------------------------------------------------- > > Key: IMPALA-4192 > URL: https://issues.apache.org/jira/browse/IMPALA-4192 > Project: IMPALA > Issue Type: Improvement > Components: Backend > Affects Versions: Impala 2.8.0 > Reporter: Michael Ho > Assignee: Michael Ho > Priority: Major > Labels: codegen > > Currently, Exprs in a fragment are scattered through the TPlanNode in a > fragment. Expr is supposed to be shared by all threads but they are always > accessed through thread-private state ExprContext. With multi-threading, an > Expr in a fragment and its generated IR function should be shared among all > instances of it. > As part of IMPALA-4080, all Expr in a fragment will be moved to query-wide > state instead of having multiple copies of them in the exec nodes of each > instances. In addition, moving Expr to query-wide state prevents the mistakes > of baking in thread private states (e.g. ExprContext pointers) into the > generated IR code for an Expr. -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-all-unsubscr...@impala.apache.org For additional commands, e-mail: issues-all-h...@impala.apache.org