[9.2] Pack dimension values in time-series aggregation (#136216) #136519
Conversation
This file contains hidden or 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
With this change, we pack the dimension into a single value before the second aggregation in time-series queries and unpack it afterward. This avoids generating permutations for multi-valued dimensions in the second aggregation, which is not desirable. For example, the query ``` TS k8s | STATS max(rate(request)) BY host, tbucket(1minute) ``` is rewritten as: ```esql TS k8s | STATS rate=rate(request), host=VALUES(host) BY _tsid, tbucket=TBUCKET(1minute) | EVAL packed_host=PACK_DIMENSION(host) | STATS sum(rate) BY packed_host, tbucket | EVAL host=UNPACK_DIMENSION(packed_host) | KEEP rate, host, tbucket ``` There is some overhead with packing and unpacking values, but we tried to isolate this behavior to time-series queries with dimension fields only. That is why I chose this approach. (cherry picked from commit c8dc04d) # Conflicts: # x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/action/EsqlCapabilities.java
kkrik-es added >non-issue :StorageEngine/TSDB Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
3 participants
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 Outdated suggestions cannot be applied.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.
Backport
This will backport the following commits from
mainto9.2:Questions ?
Please refer to the Backport tool documentation