Allow implicit type conversion in Array to QBit cast

[rienath]

Previously, casting Array to QBit required the array element type to exactly match the QBit element type. For example:

CREATE TABLE test (qbit QBit(Float32, 3)) ENGINE = Memory;
INSERT INTO test SELECT [1, 2, 3];  -- Failed with TYPE_MISMATCH

Now array elements are implicitly converted to the target QBit element type using the standard type conversion infrastructure, consistent with how other type conversions work in ClickHouse. Here is an example of a few more queries that now work:

SELECT [1, 2, 3]::QBit(Float64, 3);                       -- Array(UInt8) → QBit(Float64, 3)
SELECT CAST([0.1, 1.1] AS QBit(BFloat16, 2));             -- Array(Float64) → QBit(BFloat16, 2)

and even

INSERT INTO test SELECT arrayMap(i -> i + number, range(3)) AS qbit FROM numbers(3);

Closes: #89663.

Changelog category (leave one):

• Improvement

Changelog entry (a user-readable short description of the changes that goes into CHANGELOG.md):

Allow implicit type conversion when casting Array to QBit. Integer and float arrays can now be inserted directly into QBit columns without explicit type casts.

[clickhouse-gh]

Workflow [PR], commit [7884236]

Summary: ❌

job_name	test_name	status	info	comment
Stateless tests (amd_msan, parallel)		failure
	02801_backup_native_copy	FAIL	cidb, issue	ISSUE EXISTS
Stateless tests (amd_ubsan, parallel)		failure
	02346_text_index_parallel_replicas	FAIL	cidb, issue	ISSUE EXISTS
AST fuzzer (amd_tsan)		failure
	Logical error: Unexpected return type from A. Expected B. Got C. Action:	FAIL	cidb, issue	ISSUE EXISTS
BuzzHouse (amd_debug)		failure
	Logical error: 'Inconsistent AST formatting in SelectWithUnionQuery: the query:	FAIL	cidb	IGNORED
Performance Comparison (amd_release, master_head, 5/6)		failure
	Check Results	failure		IGNORED
Performance Comparison (amd_release, master_head, 6/6)		failure
	Check Results	failure		IGNORED
Unit tests (tsan)		error	issue	ISSUE EXISTS

[Copilot]

Pull request overview

This PR enables implicit type conversion when casting Array to QBit types in ClickHouse. Previously, array element types had to exactly match the target QBit element type, causing TYPE_MISMATCH errors. Now the standard type conversion infrastructure automatically converts array elements to the target type (e.g., Array(UInt8) → QBit(Float64, 3)), making QBit columns easier to populate.

Key Changes:

• Modified the createArrayToQBitWrapper function to apply type conversion to array elements before creating QBit values
• Updated test files to remove explicit type conversions (like toFloat32(), toBFloat16()) that are now unnecessary
• Changed expected error codes from TYPE_MISMATCH to SIZES_OF_ARRAYS_DONT_MATCH for dimension mismatches

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/Functions/FunctionsConversion.h	Implements implicit type conversion in Array→QBit cast by converting nested array elements before creating QBit
tests/queries/0_stateless/03375_l2_distance_transposed_partial_reads_pass.sql	Removes explicit toBFloat16() conversions in test queries
tests/queries/0_stateless/03370_l2_distance_transposed_negative.sql.j2	Removes explicit type conversions from reference vectors in negative test cases
tests/queries/0_stateless/03369_l2_distance_transposed_variadic.sql	Removes toFloat32() wrapper and adds clarifying comment about reference vector type requirements
tests/queries/0_stateless/03367_l2_distance_transposed_2.sql.j2	Removes explicit type conversions and updates error expectation
tests/queries/0_stateless/03367_l2_distance_transposed_2.reference.j2	Adds expected output line for newly working test case
tests/queries/0_stateless/03367_l2_distance_transposed_1.sql.j2	Removes explicit type conversions from reference vectors
tests/queries/0_stateless/03366_qbit_array_map_populate.sql	Removes explicit type conversions in arrayMap expressions
tests/queries/0_stateless/03365_qbit_casts_as_from_array.sql	Removes explicit type conversions in cast operations
tests/queries/0_stateless/03364_qbit_negative.sql	Updates error expectation and removes type conversion
tests/queries/0_stateless/03364_qbit_negative.reference	Adds expected output for newly working INSERT
tests/queries/0_stateless/03363_qbit_create_insert_select.sql	Updates expected error codes from TYPE_MISMATCH to SIZES_OF_ARRAYS_DONT_MATCH

[Copilot]

Pull request overview

Copilot reviewed 12 out of 12 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 12 out of 12 changed files in this pull request and generated 2 comments.

[pamarcos]

@rienath please merge master so that the CI runs the tests. After #92154 was merged, we should be good 👍

[rienath]

@pamarcos thanks for the review! I wasn't replying until I see that the CI is green to save your time :)

[rienath]

The only related failures are the performance tests. They fail because the script tries to run the new version of the test on master, which does not support type conversion, producing the following stack trace

Traceback (most recent call last):
  File "/home/ubuntu/actions-runner/_work/ClickHouse/ClickHouse/./tests/performance/scripts/perf.py", line 329, in <module>
    t.join()
  File "/home/ubuntu/actions-runner/_work/ClickHouse/ClickHouse/./tests/performance/scripts/perf.py", line 45, in join
    raise self.run_exception[1]
  File "/home/ubuntu/actions-runner/_work/ClickHouse/ClickHouse/./tests/performance/scripts/perf.py", line 38, in run
    super().run()
  File "/usr/lib/python3.10/threading.py", line 953, in run
    self._target(*self._args, **self._kwargs)
  File "/home/ubuntu/actions-runner/_work/ClickHouse/ClickHouse/./tests/performance/scripts/perf.py", line 317, in do_create
    connection.execute(q)
  File "/usr/local/lib/python3.10/dist-packages/clickhouse_driver/client.py", line 382, in execute
    rv = self.process_ordinary_query(
  File "/usr/local/lib/python3.10/dist-packages/clickhouse_driver/client.py", line 580, in process_ordinary_query
    return self.receive_result(with_column_types=with_column_types,
  File "/usr/local/lib/python3.10/dist-packages/clickhouse_driver/client.py", line 213, in receive_result
    return result.get_result()
  File "/usr/local/lib/python3.10/dist-packages/clickhouse_driver/result.py", line 50, in get_result
    for packet in self.packet_generator:
  File "/usr/local/lib/python3.10/dist-packages/clickhouse_driver/client.py", line 229, in packet_generator
    packet = self.receive_packet()
  File "/usr/local/lib/python3.10/dist-packages/clickhouse_driver/client.py", line 246, in receive_packet
    raise packet.exception
clickhouse_driver.errors.ServerException: Code: 53.
DB::Exception: Cannot convert from Array(Int64) to QBit(Float64, 100): while converting source column vec to destination column vec. 

[rienath]

Unit tests (tsan)

• The PR is not related to the failure

Stateless tests (amd_msan, parallel)

• 02801_backup_native_copy is flaky #92286

Stateless tests (amd_ubsan, parallel)

• Flaky 02346_text_index_parallel_replicas #89823

AST fuzzer (amd_tsan)

• Logical error: Unexpected return type from A. Expected B. Got C. Action: (STID: 1611-3d19) #91672

BuzzHouse (amd_debug)

• BuzzHouse found unrelated error

Performance tests are giving expected errors as mentioned earlier

[rienath]

We usually don't backport improvements, but this one makes user experience much nicer and Christmas / New Year is soon. Let's make it a gift 🎁