[chore](regression) Merge nereids_p0 test cases into query_p0

[morrySnow]

Proposed changes

Merge unique test content from nereids_p0 regression tests into query_p0 to eliminate duplication.

What problem does this PR solve?

Issue Number: close #xxx

Problem Summary: The regression-test/suites/nereids_p0/ folder was copied from query_p0 approximately 4 years ago to develop the Nereids optimizer. Now that Nereids is the default optimizer, there are 119 files at the same relative path in both folders with overlapping test coverage. This PR merges all unique test content from nereids_p0 into query_p0 to consolidate these tests into a single location.

Scope of changes:

• 42 Groovy test files in regression-test/suites/query_p0/ modified to include unique test cases from nereids_p0
• 24 .out golden output files updated with expected results for newly added tests
• 1 new .out file created (session_variable/test_default_limit.out)
• All enable_nereids_planner settings removed from merged content (Nereids is now default)
• All nereids_test_query_db references replaced with test_query_db
• 77 files where query_p0 already contained all content from nereids_p0 (no changes needed)

Key large merges:

• explain/test_pushdown_explain.groovy: +391 lines of pushdown predicate tests
• sql_functions/spatial_functions/test_gis_function.groovy: +354 lines of spatial function tests
• subquery/test_subquery.groovy: +253 lines of subquery tests
• sql_functions/datetime_functions/test_date_function.groovy: +190+ lines of datetime tests
• join/test_runtimefilter_on_datev2.groovy: +112 lines of runtime filter tests

Release note

None

Check List (For Author)

• Test: No need to test - this is a test file reorganization, merging test content from nereids_p0 into query_p0. The merged tests themselves serve as the test.
• Behavior changed: No
• Does this need documentation: No

[hello-stephen]

Thank you for your contribution to Apache Doris.
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Please clearly describe your PR:

1. What problem was fixed (it's best to include specific error reporting information). How it was fixed.
2. Which behaviors were modified. What was the previous behavior, what is it now, why was it modified, and what possible impacts might there be.
3. What features were added. Why was this function added?
4. Which code was refactored and why was this part of the code refactored?
5. Which functions were optimized and what is the difference before and after the optimization?

[morrySnow]

/review

[morrySnow]

run buildall

[morrySnow]

you should remove the entire nereids_p0 if you confirm all cases in it has been merged into query_p0

[github-actions]

OpenCode automated review failed and did not complete.

Error: Review step was failure (possibly timeout or cancelled)
Workflow run: https://github.com/apache/doris/actions/runs/23679918212

Please inspect the workflow logs and rerun the review after the underlying issue is resolved.

[morrySnow]

/review

[morrySnow]

@morrySnow Updated the PR:

1. Fixed all 25 .out golden output file mismatches — regenerated by running all affected tests against a local Doris cluster
2. Fixed test_pushdown_explain — the REWRITE_SIMPLE_AGG_TO_CONSTANT rule was folding count() to constants using metadata row counts, preventing pushAggOp testing. Added SET disable_nereids_rules and extra test data rows
3. Removed the 119 merged nereids_p0 files — both .groovy test files and corresponding .out golden output files that have been merged into query_p0 are now deleted

Note: nereids_p0 has 485 total files, of which 119 had counterparts in query_p0 (now merged and removed). The remaining 366 files exist only in nereids_p0 and would need separate handling.

[morrySnow]

run buildall

[github-actions]

OpenCode automated review failed and did not complete.

Error: Review step was failure (possibly timeout or cancelled)
Workflow run: https://github.com/apache/doris/actions/runs/23682453853

Please inspect the workflow logs and rerun the review after the underlying issue is resolved.

[morrySnow]

run buildall

[morrySnow]

/review

[morrySnow]

Updated: Moved all remaining 366 nereids_p0 test files + 217 data files to query_p0 and completely removed the nereids_p0 directory (both suites and data).

Changes in latest commit:

• Moved unique groovy/SQL/data files to query_p0 at the same relative paths
• Removed enable_nereids_planner / enable_fallback_to_original_planner SET statements
• Updated suite tags from nereids_p0 to query_p0
• Fixed hardcoded database names (regression_test_nereids_p0_* → regression_test_query_p0_*)
• Replaced nereids_test_query_db with test_query_db
• Deleted entire regression-test/suites/nereids_p0/ and regression-test/data/nereids_p0/

[github-actions]

Code Review Summary — PR #61842

Overview

This PR consolidates regression tests by merging unique test content from nereids_p0 into query_p0 and deleting the nereids_p0 duplicates (1107 files, 68 modified groovy files, ~1000 deleted files). The merge is well-executed overall — database references (nereids_test_query_db → test_query_db) and Nereids planner settings have been properly cleaned up.

Critical Checkpoint Conclusions

Checkpoint	Conclusion
Goal accomplished?	Yes. Unique nereids_p0 content is merged into query_p0; nereids_p0 is deleted. No test coverage is lost.
Modification focused/minimal?	Appropriate for scope — pure test reorganization with no production code changes.
Concurrency	N/A — test files only.
Lifecycle management	N/A
Configuration items	N/A
Incompatible changes	N/A
Parallel code paths	N/A
Test coverage	This PR is about tests — the merged tests themselves verify functionality.
Observability	N/A
Transaction/persistence	N/A
Data writes	N/A
FE-BE variable passing	N/A
Performance	N/A
Other issues	Minor issues noted below

Issues Found (all minor/low severity)

1. Typo: "seession" → "session" in test_pushdown_explain.groovy (3 occurrences in newly added content). Cosmetic but should be fixed.

2. Tables dropped after use in test_subquery.groovy — the newly merged content drops tables both before creation AND after use (e.g., test_one_row_relation, table_23_undef_undef, table_100_undef_*, scalar_subquery_t). Per AGENTS.md: "After completing tests, do not drop tables; instead drop tables before using them in tests, to preserve the environment for debugging."

3. def tableScale6 pattern in test_date_function.groovy — uses def tableScale6 = "dtv2s6" instead of hardcoding the table name directly in SQL. Per AGENTS.md: "For ordinary single test tables, do not use def tableName form; instead hardcode your table name in all SQL." (Low priority since this is inherited from nereids_p0 and the existing file already uses def tableName.)

4. Tables dropped after use in test_date_function.groovy — test_period_union is dropped both before and after use.

5. Massive qt_sql tag reuse in test_gis_function.groovy — all ~354 newly added queries use the bare qt_sql tag. While this works (the framework matches tags positionally), it makes .out file maintenance fragile and debugging difficult. This is a pre-existing pattern in the file that is significantly amplified by this PR.

Verdict

No blocking issues. The merge is mechanically correct — nereids planner settings are properly removed, database references are updated, content is logically integrated, and .out files match the groovy queries. The issues found are minor style/convention violations, mostly inherited from the original nereids_p0 source material.

[morrySnow]

run buildall

[morrySnow]

/review

[github-actions]

Code Review Summary

Scope: This PR consolidates unique test content from nereids_p0 regression tests into query_p0, eliminating duplication now that the Nereids optimizer is the default. ~1201 files changed (34k additions, 88k deletions), almost entirely test file reorganization.

Reviewed Checkpoints

1. Obsolete settings removed — Confirmed: zero new additions of enable_nereids_planner, enable_fallback_to_original_planner, or nereids_test_query_db in any added lines. All legacy Nereids-specific settings have been properly cleaned up.

2. Test patterns — Tests correctly use qt_, order_qt_, test { }, and explain { } patterns. Tables are dropped with IF EXISTS before creation (34 instances verified).

3. Session variable management — Properly handled. For example in test_subquery.groovy, disable_nereids_rules is set and reset correctly around relevant test blocks.

4. .out golden files — Updated consistently to match new qt_ test case additions and path renames from nereids_p0 to query_p0.

5. No newline-at-EOF issues in newly added content.

Minor Issue

In regression-test/suites/query_p0/aggregate/aggregate_group_by_metric_type.groovy, there is a DROP TABLE test_group_by_array at the end of the test without IF EXISTS. Per test standards, tables should be dropped before use (not after), and should use IF EXISTS. This is a pre-existing issue carried over from nereids_p0, so it's minor and non-blocking.

Verdict

The PR is a straightforward and well-executed test consolidation. No functional concerns found.