Don't load global ordinals with the map execution_hint
#37833
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
|
Pinging @elastic/es-analytics-geo |
polyfractal
approved these changes
Jan 31, 2019
| if (executionMode == ExecutionMode.MAP) { | ||
| // global ordinals are not requested so we don't load them | ||
| // and return the biggest cardinality per segment instead. | ||
| long maxOrd = -1; |
There was a problem hiding this comment.
I noticed below there's an assert for -1 down below, and in production with assertions off that'd fall through to a ratio that is under the threshold and triggers a LowCardinality strategy (potentially).
Is this just a sanity assertion, or is there an actual chance of having "no cardinality" in each segment and actually returning -1? What I'm basically asking is if we should handle -1 explicitly below or not :)
There was a problem hiding this comment.
The assertion is only for the global_ordinals execution and in such case we always call ValuesSource.Bytes.WithOrdinals#globalMaxOrd that returns values greater or equals than 0 so I think we're good here.
jasontedor
added a commit
to jasontedor/elasticsearch
that referenced
this pull request
Feb 1, 2019
* master: (36 commits) Ensure joda compatibility in custom date formats (elastic#38171) Do not compute cardinality if the `terms` execution mode does not use `global_ordinals` (elastic#38169) Do not set timeout for IndexRequests in GatewayIndexStateIT (elastic#38147) Zen2ify testMasterFailoverDuringIndexingWithMappingChanges (elastic#38178) SQL: [Docs] Add limitation for aggregate functions on scalars (elastic#38186) Add elasticsearch-node detach-cluster command (elastic#37979) Add tests for fractional epoch parsing (elastic#38162) Enable bw tests for elastic#37871 and elastic#38032. (elastic#38167) Clear send behavior rule in CloseWhileRelocatingShardsIT (elastic#38159) Fix testCorruptedIndex (elastic#38161) Add finalReduce flag to SearchRequest (elastic#38104) Forbid negative field boosts in analyzed queries (elastic#37930) Remove AtomiFieldData#getLegacyFieldValues (elastic#38087) Universal cluster bootstrap method for tests with autoMinMasterNodes=false (elastic#38038) Fix FullClusterRestartIT.testHistoryUUIDIsAdded (elastic#38098) Replace joda time in ingest-common module (elastic#38088) Fix eclipse config for ssl-config (elastic#38096) Don't load global ordinals with the `map` execution_hint (elastic#37833) Relax fault detector in some disruption tests (elastic#38101) Fix java time epoch date formatters (elastic#37829) ...
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
The
termsaggregator loads the global ordinals to retrieve the cardinality of the field to aggregate on. This information is then used to select the strategy to use for the aggregation (breadth_firstordepth_first). However this should be avoided if theexecution_hintis explicitly set tomapsince this mode doesn't really need the global ordinals. Since we still need the cardinality of the field this change picks the maximum cardinality in the segments as an estimation of the total cardinality to select the strategy to use (breadth_firstordepth_first). This estimation is only used if the execution hint is set tomap, otherwise the global ordinals are still used to retrieve the accurate cardinality.Closes #37705