[Core] support limit pushdown with pk table #6914
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JingsongLi
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Dec 29, 2025
| files = postFilterManifestEntries(files); | ||
| } | ||
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| if (supportsLimitPushManifestEntries()) { |
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Purpose
一、Background
Issue: #6847
Append table limit pushdown : #6848
This pr is to support limit pushdown with pk table.
二、Code Logic
We try best to filtering manifest entries before data reading.
Limit pushdown is only enabled for DEDUPLICATE/FIRST_ROW merge engines without deletion vectors, as accurate counting requires no merge operations or deleted rows.
We groups files by (partition, bucket) pairs and processes buckets sequentially. For each bucket, the algorithm checks if safe pushdown is possible: files must have no overlapping (same LSM level, excluding level 0) and no delete rows.
1、If safe, it accumulates row counts from file metadata until reaching the limit, then stops processing remaining buckets. 2、If unsafe (overlapping files or delete rows exist), all files in that bucket are included.
Linked issue: close #xxx
Tests
API and Format
Documentation