* Always return sketches from DS_HLL, DS_THETA, DS_QUANTILES_SKETCH.
These aggregation functions are documented as creating sketches. However,
they are planned into native aggregators that include finalization logic
to convert the sketch to a number of some sort. This creates an
inconsistency: the functions sometimes return sketches, and sometimes
return numbers, depending on where they lie in the native query plan.
This patch changes these SQL aggregators to _never_ finalize, by using
the "shouldFinalize" feature of the native aggregators. It already
existed for theta sketches. This patch adds the feature for hll and
quantiles sketches.
As to impact, Druid finalizes aggregators in two cases:
- When they appear in the outer level of a query (not a subquery).
- When they are used as input to an expression or finalizing-field-access
post-aggregator (not any other kind of post-aggregator).
With this patch, the functions will no longer be finalized in these cases.
The second item is not likely to matter much. The SQL functions all declare
return type OTHER, which would be usable as an input to any other function
that makes sense and that would be planned into an expression.
So, the main effect of this patch is the first item. To provide backwards
compatibility with anyone that was depending on the old behavior, the
patch adds a "sqlFinalizeOuterSketches" query context parameter that
restores the old behavior.
Other changes:
1) Move various argument-checking logic from runtime to planning time in
DoublesSketchListArgBaseOperatorConversion, by adding an OperandTypeChecker.
2) Add various JsonIgnores to the sketches to simplify their JSON representations.
3) Allow chaining of ExpressionPostAggregators and other PostAggregators
in the SQL layer.
4) Avoid unnecessary FieldAccessPostAggregator wrapping in the SQL layer,
now that expressions can operate on complex inputs.
5) Adjust return type to thetaSketch (instead of OTHER) in
ThetaSketchSetBaseOperatorConversion.
* Fix benchmark class.
* Fix compilation error.
* Fix ThetaSketchSqlAggregatorTest.
* Hopefully fix ITAutoCompactionTest.
* Adjustment to ITAutoCompactionTest.
* Frame processing and channels.
Follow-up to #12745. This patch adds three new concepts:
1) Frame channels are interfaces for doing nonblocking reads and writes
of frames.
2) Frame processors are interfaces for doing nonblocking processing of
frames received from input channels and sent to output channels.
3) Cluster-by keys, which can be used for sorting or partitioning.
The patch also adds SuperSorter, a user of these concepts, both to
illustrate how they are used, and also because it is going to be useful
in future work.
Central classes:
- ReadableFrameChannel. Implementations include
BlockingQueueFrameChannel (in-memory channel that implements both interfaces),
ReadableFileFrameChannel (file-based channel),
ReadableByteChunksFrameChannel (byte-stream-based channel), and others.
- WritableFrameChannel. Implementations include BlockingQueueFrameChannel
and WritableStreamFrameChannel (byte-stream-based channel).
- ClusterBy, a sorting or partitioning key.
- FrameProcessor, nonblocking processor of frames. Implementations include
FrameChannelBatcher, FrameChannelMerger, and FrameChannelMuxer.
- FrameProcessorExecutor, an executor service that runs FrameProcessors.
- SuperSorter, a class that uses frame channels and processors to
do parallel external merge sort of any amount of data (as long as there
is enough disk space).
* Additional tests, fixes.
* Changes from review.
* Better implementation for ReadableInputStreamFrameChannel.
* Rename getFrameFileReference -> newFrameFileReference.
* Add InterruptedException to runIncrementally; add more tests.
* Cancellation adjustments.
* Review adjustments.
* Refactor BlockingQueueFrameChannel, rename doneReading and doneWriting to close.
* Additional changes from review.
* Additional changes.
* Fix test.
* Adjustments.
* Adjustments.
True, false, and null have different meanings: true/false mean "legacy"
and "not legacy"; null means use the default set by ScanQueryConfig.
So, we need to respect this in the JsonIgnore setup.
* Remove null and empty fields from native queries
* Test fixes
* Attempted IT fix.
* Revisions from review comments
* Build fixes resulting from changes suggested by reviews
* IT fix for changed segment size
* Scan: Add "orderBy" parameter.
This patch adds an API for requesting non-time orderings, although it
does not actually add the ability to execute such queries.
The changes are done in such a way that no matter how Scan query objects
are constructed, they will have a correct "getOrderBy". This will enable
us to switch the execution to exclusively use "getOrderBy" later on when
it's implemented.
Scan queries are serialized such that they only include "order" (time
order) if the ordering is time-based, and they only include "orderBy" if
the ordering is non-time-based. This maximizes compatibility with
the existing API while also providing a clean look for formatted queries.
Because this patch does not include execution logic, if someone actually
tries to run a query with non-time ordering, then they will get an error
like "Cannot execute query with orderBy [quality ASC]".
* SQL module fixes.
* Add spotbugs-exclude.
* Remove unused method.
* Add "offset" parameter to the Scan query.
It works by doing the query as normal and then throwing away the first
"offset" number of rows on the broker.
* Fix constructor call.
* Fix up JSONs.
* Fix call to ScanQuery.
* Doc update.
* Fix javadocs.
* Spotbugs, LGTM suppressions.
* Javadocs.
* Fix suppression.
* Stabilize Scan query result order, add tests.
* Update LGTM comment.
* Fixup.
* Test different batch sizes too.
* Nicer tests.
* Fix comment.
* Add "offset" parameter to GroupBy query.
It works by doing the query as normal and then throwing away the first
"offset" number of rows on the broker.
* Stabilize GroupBy sorts.
* Fix inspections.
* Fix suppression.
* Fixups.
* Move TopNSequence to druid-core.
* Addl comments.
* NumberedElement equals verification.
* Changes from review.
* Add Spotbugs
Exclude all the issues for now, so we can add them one by one.
(cherry picked from commit ceda4754dc8c703d1e0de85b48cd5f5409cfd5b7)
* Add additional rules to the list
* More rules
* More rules
* Add comments to the xml
* Move the spotbugs-exclude.xml to codestyle/
Gian Merlino
Paul Rogers
Laksh Singla
Lasse Krogh Mammen
Jonathan Wei
Fokko Driesprong
Clint Wylie
Fokko Driesprong