Hi, I've been working on JIRA issue [IOTDB-190 switch to ANTLR v4] these days.
I implemented the SQL parsing module. However, it seems that the parsing efficiency reduces a lot when using ANTLR v4. It turns out that RuleContext.getText() is frequently called, which takes more than 90% of the CPU time. The grammer definition (.g4 file) here is a continuation of previous version (ANTLR v3). There are some grammar definitions that are too detailed, such as decimal numbers, which are categorized into many types. I think making the rules more general may decrease the times of calling getText() method. I plan to reconstruct the grammer definition to improve the parsing efficiency. ---- Yuyuan KANG 在2019-09-06 13:30:00,Yuyuan KANG (Jira)<[email protected]>写道： > Yuyuan KANG created IOTDB-201: > --------------------------------- > > Summary: Query parsing runs slower when using ANTLR v4 > Key: IOTDB-201 > URL: https://issues.apache.org/jira/browse/IOTDB-201 > Project: Apache IoTDB > Issue Type: Improvement > Reporter: Yuyuan KANG > > > The system now uses ANTLR v3. When transformed to ANTLR v4 using previous > grammar definition, experiment result shows that the efficiency of logical > plan generation is negatively impacted. > > > > -- > This message was sent by Atlassian Jira > (v8.3.2#803003)
