| # Tutorial of Nereids minidump |
| Minidump is a basic dump file for Nereids optimizer which arms |
| to replay problems and used as unit test tool for developers. |
| It include minimal necessary informations for Nereids optimizer |
| to replay a scenario in Optimizer. |
| |
| ## Save minidump file |
| In two cases fe would save minidump file |
| - when query throw an exception |
| - when use 'set enable_minidump=true;' switch by User |
| |
| ## File structure of minidump file |
| Minidump files would save in $DORIS_HOME/log/minidump path |
| and named by queryId like: c9bf82b70ce34c28-8d281e31412f3ee6.json |
| File structure of minidump file includes: |
| | key | Value | |
| |:----|:----| |
| |Sql | original sql string | |
| |SessionVariables | sessionVariables different than default | |
| |DatabaseName | database name| |
| |Tables | schemas in table, partition info and some table properties | |
| |ColocateTableIndex | table distribute informations | |
| |ColumnStatistics | all ColumnStatistics in table | |
| |Histogram | all histogram information in table| |
| |ParsedPlan | plan after parsed in json format| |
| |ResultPlan | plan after all optimized in json format| |
| |
| ## Use of nereids_ut.sh |
| When we want to use this shell, we need to go to output/fe/minidump path |
| Now only one parameter is allowed for this shell which is directory |
| of minidump files like $DORIS_HOME/log/minidump |
| ```shell |
| cd output/fe/minidump |
| ./nereids_ut.sh --d $minidump_files_path |
| ``` |
| The running reports can be found in output/fe/minidump/log |
| which is minidump.out |
| |
