kaijianding commented on a change in pull request #11379:
URL: https://github.com/apache/druid/pull/11379#discussion_r663808475
##########
File path:
processing/src/main/java/org/apache/druid/query/groupby/strategy/GroupByStrategyV2.java
##########
@@ -213,7 +216,48 @@ public boolean doMergeResults(final GroupByQuery query)
context.put("finalize", false);
context.put(GroupByQueryConfig.CTX_KEY_STRATEGY,
GroupByStrategySelector.STRATEGY_V2);
context.put(CTX_KEY_OUTERMOST, false);
- if (query.getUniversalTimestamp() != null) {
+ Map<String, Object> timestampFieldContext =
GroupByQueryHelper.findTimestampResultField(query);
+ context.putAll(timestampFieldContext);
+
+ Granularity granularity = query.getGranularity();
+ List<DimensionSpec> dimensionSpecs = query.getDimensions();
+ final String timestampResultField = (String)
timestampFieldContext.get(GroupByQuery.CTX_TIMESTAMP_RESULT_FIELD);
+ final boolean hasTimestampResultField = timestampResultField != null
+ &&
query.getContextBoolean(CTX_KEY_OUTERMOST, true);
+ int timestampResultFieldIndex = 0;
+ if (hasTimestampResultField) {
+ // sql like "group by city_id,time_floor(__time to day)",
+ // the original translated query is granularity=all and dimensions:[d0,
d1]
+ // the better plan is granularity=day and dimensions:[d0]
+ // but the ResultRow structure is changed from [d0, d1] to [__time, d0]
+ // this structure should be fixed as [d0, d1] (actually it is [d0,
__time]) before postAggs are called
+ final Granularity timestampResultFieldGranularity
+ = (Granularity)
timestampFieldContext.get(GroupByQuery.CTX_TIMESTAMP_RESULT_FIELD_GRANULARITY);
+ dimensionSpecs =
+ query.getDimensions()
+ .stream()
+ .filter(dimensionSpec ->
!dimensionSpec.getOutputName().equals(timestampResultField))
+ .collect(Collectors.toList());
+ granularity = timestampResultFieldGranularity;
+ // when timestampResultField is the last dimension, should set
sortByDimsFirst=true,
+ // otherwise the downstream is sorted by row's timestamp first which
makes the final ordering not as expected
+ timestampResultFieldIndex = (int)
timestampFieldContext.get(GroupByQuery.CTX_TIMESTAMP_RESULT_FIELD_INDEX);
+ if (!query.getContextSortByDimsFirst() && timestampResultFieldIndex ==
query.getDimensions().size() - 1) {
+ context.put(GroupByQuery.CTX_KEY_SORT_BY_DIMS_FIRST, true);
+ }
+ // when timestampResultField is the first dimension and
sortByDimsFirst=true,
+ // it is actually equals to sortByDimsFirst=false
+ if (query.getContextSortByDimsFirst() && timestampResultFieldIndex == 0)
{
+ context.put(GroupByQuery.CTX_KEY_SORT_BY_DIMS_FIRST, false);
+ }
+ // when hasTimestampResultField=true and timestampResultField is neither
first nor last dimension,
+ // the DefaultLimitSpec will always do the reordering
+ }
Review comment:
Ok, I have rollback some codes.
Currently, timestampResultField is passed from query context in
`DruidQuery.toGroupByQuery`.
The granularity=all and sortByDimsFirst are still unchanged in `DruidQuery`,
because some code relies on the granularity and sortByDimsFirst like subtotals,
in another word, the basic idea is still to treat this optimization as group by
inner process improvement.
Please check the latest version of code.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
