feat: add cost to explain pruning stats

[KKould]

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Summary

• fixes: feat: add cost to explain pruning stats #15911

root@localhost:8000/default/default> EXPLAIN ANALYZE SELECT * FROM article where article_id < 3;

EXPLAIN ANALYZE
SELECT
  *
FROM
  article
where
  article_id < 3

-[ EXPLAIN ]-----------------------------------
Filter
├── output columns: [article.article_id (#0), article.author_id (#1), article.viewer_id (#2), article.view_date (#3)]
├── filters: [is_true(article.article_id (#0) < 3)]
├── estimated rows: 3.00
└── TableScan
    ├── cpu time: 80.847814ms
    ├── wait time: 423.744107ms
    ├── output rows: 4
    ├── output bytes: 80.00 B
    ├── bytes scanned: 80.00 B
    ├── runtime filter inlist/min-max time: 2.413µs
    ├── table: default.default.article
    ├── scan id: 0
    ├── output columns: [article_id (#0), author_id (#1), viewer_id (#2), view_date (#3)]
    ├── read rows: 4
    ├── read size: < 1 KiB
    ├── partitions total: 6
    ├── partitions scanned: 4
    ├── pruning stats: [segments: <range pruning: 6 to 4 cost: 6 ms>, blocks: <range pruning: 4 to 4 cost: 1 ms>]
    ├── push downs: [filters: [is_true(article.article_id (#0) < 3)], limit: NONE]
    └── estimated rows: 6.00

21 rows explain in 14.880 sec. Processed 0 rows, 0 B (0 row/s, 0 B/s)

Tests

• Unit Test
• Logic Test
• Benchmark Test
• No Test - TODO: Cost is dynamic and difficult to test in logic tests.

Type of change

• Bug Fix (non-breaking change which fixes an issue)
• New Feature (non-breaking change which adds functionality)
• Breaking Change (fix or feature that could cause existing functionality not to work as expected)
• Documentation Update
• Refactoring
• Performance Improvement
• Other (please describe):

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This change is 

[Copilot]

Pull request overview

This PR adds cost tracking to the explain pruning statistics feature, controlled by a new session setting explain_pruner_cost. The implementation measures the time spent in different pruning phases (segment range, block range, bloom filter, inverted index, and vector index) and displays this information in EXPLAIN ANALYZE output.

• Introduces a PruningCostController that uses RAII guards to measure pruning costs
• Adds timing measurements for all pruning operations (segments and blocks)
• Extends the PruningStatistics struct to include cost fields (in microseconds)
• Adds formatting support to display costs in explain output

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/query/storages/fuse/src/pruning/pruning_statistics.rs	Adds PruningCostController, PruningCostGuard, and cost tracking fields to FusePruningStatistics
src/query/storages/fuse/src/pruning/segment_pruner.rs	Integrates cost measurement for segment range pruning
src/query/storages/fuse/src/pruning/block_pruner.rs	Integrates cost measurement for block range, bloom, and inverted index pruning
src/query/storages/fuse/src/pruning/vector_index_pruner.rs	Integrates cost measurement for vector index pruning
src/query/storages/fuse/src/pruning/fuse_pruner.rs	Collects cost statistics and populates the PruningStatistics structure
src/query/storages/fuse/src/pruning/mod.rs	Exports new cost controller types
src/query/settings/src/settings_default.rs	Adds explain_pruner_cost setting (default: 0)
src/query/settings/src/settings_getter_setter.rs	Adds getter for explain_pruner_cost setting
src/query/sql/src/planner/planner.rs	Extends QueryKind::Explain to include ExplainAnalyze
src/query/service/src/physical_plans/format/common.rs	Adds cost suffix formatting for pruning statistics display
src/query/catalog/src/plan/pruning_statistics.rs	Extends PruningStatistics with cost fields and backward-compatible serialization

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[BohuTANG]

@codex review

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. What shall we delve into next?

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