[core] Rebuild file index over the correct column after schema evolution - #10122
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jackylee-ch wants to merge 2 commits into
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FileIndexProcessor computes projectedIndexCols as the index columns' positions in the file schema, and creates the index writer with fileSchema.project(projectedIndexCols). The reader, however, was built with ReadBuilder.withProjection(projectedIndexCols), which resolves the indices against the current table schema. Once a schema change shifts column positions (for example dropping a middle column and adding another), the file-schema index no longer matches the table-schema index, so the reader returns a different column and the file index is rebuilt over it. A later query on the indexed column then silently prunes files that actually match. Read the columns with withReadType(fileSchema.project(projectedIndexCols)), the same file-schema projection the writer uses, so the reader and writer stay in the file's own column space. rewrite_file_index reads a single data file whose committed schema is that file schema, and file indexes are probed at query time with predicates devolved to the file schema, so the per-file index must be built in the file's column and type space. The name-mapping half of schema evolution was added with the rewrite_file_index procedure in apache#6562, but the reader projection was never aligned to it.
Akash3121
approved these changes
Sep 23, 2026
| Map<String, String> options = new HashMap<>(); | ||
| options.put(CoreOptions.BUCKET.key(), "1"); | ||
| options.put(CoreOptions.FILE_FORMAT.key(), "parquet"); | ||
| options.put(CoreOptions.FILE_INDEX + ".bloom-filter.columns", "v"); |
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non blocking
Could this test use file-index.bitmap.columns instead of a Bloom filter? A Bloom-filter positive is probabilistic, so remain() == true does not strictly prove that 100 was indexed from v ; a false positive could allow the old wrong-column behavior to pass. The bitmap index returns an exact empty result for an absent value, making this regression deterministic while preserving the same schema-evolution scenario.
Switch the schema-evolution regression test from a bloom filter to a bitmap index. A bloom-filter positive is probabilistic, so remain() == true does not strictly prove the value was indexed from the correct column - a false positive could let the old wrong-column behavior pass. A bitmap index returns an exact empty result for an absent value, so the test now reads the (embedded) index and asserts the indexed value is present while an absent value is not.
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Purpose
FileIndexProcessor(therewrite_file_indexprocedure) rebuilds a data file's file index. It computesprojectedIndexColsas the index columns' positions in the file schema and builds the writer withfileSchema.project(projectedIndexCols). But the reader usedReadBuilder.withProjection(projectedIndexCols), whichReadBuilderImplresolves against the current table schema.For a file whose
schemaIddiffers from current, the spaces diverge once columns shift:[k, a, v](bloom onv) → dropa, addwleavesvat file-index 2 while current-index 2 is noww. The reader then readsw(null-filled for the old file), so the bloom is rebuilt over nulls and a laterv = 100query silently prunes the file.Fix: read with
withReadType(fileSchema.project(projectedIndexCols))— the writer's own file-schema projection — so reader and writer share the file's column space. Current-schema files are unchanged.Tests
testRebuildsIndexOnCorrectColumnAfterColumnDropAndAdd: bloom onvin[k, a, v], writev=100, dropa, addw, rebuild, assert thevbloom still reports100present. Fails on master (wrong column →100absent); passes here.