ehds opened a new pull request, #29362:
URL: https://github.com/apache/flink/pull/29362
…uate DEFINE aggregations and avoid extracting all matched pattern events
<!--
*Thank you very much for contributing to Apache Flink - we are happy that
you want to help us improve Flink. To help the community review your
contribution in the best possible way, please go through the checklist below,
which will get the contribution into a shape in which it can be best reviewed.*
*Please understand that we do not do this to make contributions to Flink a
hassle. In order to uphold a high standard of quality for code contributions,
while at the same time managing a large number of contributions, we need
contributors to prepare the contributions well, and give reviewers enough
contextual information for the review. Please also understand that
contributions that do not follow this guide will take longer to review and thus
typically be picked up with lower priority by the community.*
## Contribution Checklist
- Make sure that the pull request corresponds to a [JIRA
issue](https://issues.apache.org/jira/projects/FLINK/issues). Exceptions are
made for typos in JavaDoc or documentation files, which need no JIRA issue.
- Name the pull request in the form "[FLINK-XXXX] [component] Title of the
pull request", where *FLINK-XXXX* should be replaced by the actual issue
number. Skip *component* if you are unsure about which is the best component.
Typo fixes that have no associated JIRA issue should be named following
this pattern: `[hotfix] [docs] Fix typo in event time introduction` or
`[hotfix] [javadocs] Expand JavaDoc for PuncuatedWatermarkGenerator`.
- Fill out the template below to describe the changes contributed by the
pull request. That will give reviewers the context they need to do the review.
- Make sure that the change passes the automated tests, i.e., `mvn clean
verify` passes. You can set up Azure Pipelines CI to do that following [this
guide](https://cwiki.apache.org/confluence/display/FLINK/Azure+Pipelines#AzurePipelines-Tutorial:SettingupAzurePipelinesforaforkoftheFlinkrepository).
- Each pull request should address only one issue, not mix up code from
multiple issues.
- Each commit in the pull request has a meaningful commit message
(including the JIRA id)
- Once all items of the checklist are addressed, remove the above text and
this checklist, leaving only the filled out template below.
**(The sections below can be removed for hotfixes of typos)**
-->
## What is the purpose of the change
The `IterativeCondition` generated for MATCH_RECOGNIZE DEFINE clauses
currently does eager per-event work: it extracts *all* events matched so far
for each referenced pattern variable from the NFA state (even when only the
current event is needed), and computes *all* aggregates before evaluating the
condition (even when a leading conjunct already decided the result). For long
matched sequences this is O(N) work per event, i.e. O(N²) overall. This change
makes both on-demand.
## Brief change log
- `MatchCodeGenerator`: when a DEFINE condition references the last event
of its own pattern variable (`LAST(C, 0)` semantics), generate a single-element
list wrapping the incoming event instead of extracting all matched events;
extends the existing fast path for `*`
- Pattern event list construction and aggregate computation are wrapped in
per-record memoized `Supplier`s, so `&&` short-circuiting skips the work when
it is not read; one aggregate-row supplier is shared per pattern variable, so
aggregates still run at most once per record
- Added regression tests proving the lazy behaviour with a throwing
sentinel function
## Verifying this change
This change added tests and can be verified as follows:
- Added `testAggregationInDefineNotEvaluatedWhenShortCircuited` to the
stream `MatchRecognizeITCase`: a sentinel function that throws on a marker
value feeds an aggregate guarded by a leading conjunct; the job must succeed
(aggregate never evaluated). A negative control asserts the job fails when the
conjunct passes (aggregate is evaluated). Same pattern as `ThrowingFunction` in
`CoalesceFunctionITCase`
- Existing tests pass: `MatchRecognizeITCase` (stream: heap + rocksdb,
batch), `MatchRecognizeTest` plan tests, `MatchRecognizeValidationTest`
## Does this pull request potentially affect one of the following parts:
- Dependencies: no
- The public API (`@Public(Evolving)`): no
- The serializers: no
- The runtime per-record code paths (performance sensitive): **yes**
(generated per-record
filter code; this is the point of the change)
- Anything that affects deployment or recovery: no
- The S3 file system connector: no
## Documentation
- Does this pull request introduce a new feature? no
- [X] Yes (please specify the tool below)
---
##### Was generative AI tooling used to co-author this PR?
<!--
If generative AI tooling has been used in the process of authoring this PR,
please
change the checkbox below to `[X]` and replace the placeholder in the
"Generated-by"
line with the tool name and version. Otherwise remove the "Generated-by"
line.
See the ASF Generative Tooling Guidance for details:
https://www.apache.org/legal/generative-tooling.html
You are responsible for the quality and correctness of every change in this
PR
regardless of the tooling used. Low-effort AI-generated PRs will be closed.
See
AGENTS.md for the full guidance.
-->
- [ ] Yes (please specify the tool below)
Generated-by: [Tool Name and Version]
--
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]
