zhoulii opened a new issue, #7811: URL: https://github.com/apache/paimon/issues/7811
### Search before asking - [x] I searched in the [issues](https://github.com/apache/paimon/issues) and found nothing similar. ### Paimon version 1.14 ### Compute Engine flink 1.18 ### Minimal reproduce step ```java @Test public void testMetaSelectorWithEmptyStringKey() { // Simulate the real NPE scenario: btree index file with empty string as firstKey KeySerializer stringSerializer = KeySerializer.create(new VarCharType()); byte[] emptyKey = stringSerializer.serialize(BinaryString.EMPTY_UTF8); byte[] normalKey = stringSerializer.serialize(BinaryString.fromString("www.example.com")); BTreeIndexMeta metaWithEmptyFirstKey = new BTreeIndexMeta(emptyKey, normalKey, false); BTreeIndexMeta metaWithNormalKeys = new BTreeIndexMeta( stringSerializer.serialize(BinaryString.fromString("aaa.com")), stringSerializer.serialize(BinaryString.fromString("zzz.com")), false); BTreeIndexMeta metaOnlyNulls = new BTreeIndexMeta(null, null, true); List<GlobalIndexIOMeta> files = Arrays.asList( new GlobalIndexIOMeta( new Path("file_empty"), 1, metaWithEmptyFirstKey.serialize()), new GlobalIndexIOMeta( new Path("file_normal"), 1, metaWithNormalKeys.serialize()), new GlobalIndexIOMeta( new Path("file_nulls"), 1, metaOnlyNulls.serialize())); FieldRef ref = new FieldRef(1, "page_host", new VarCharType()); BTreeFileMetaSelector selector = new BTreeFileMetaSelector(files, stringSerializer); // visitEqual should not throw NPE Optional<List<GlobalIndexIOMeta>> result = selector.visitEqual(ref, BinaryString.fromString("www.example.com")); Assertions.assertThat(result).isNotEmpty(); assertFiles(result.get(), Arrays.asList("file_empty", "file_normal")); // visitLessThan should not throw NPE result = selector.visitLessThan(ref, BinaryString.fromString("bbb.com")); Assertions.assertThat(result).isNotEmpty(); assertFiles(result.get(), Arrays.asList("file_empty", "file_normal")); // visitGreaterThan should not throw NPE result = selector.visitGreaterThan(ref, BinaryString.fromString("www.example.com")); Assertions.assertThat(result).isNotEmpty(); // visitIn should not throw NPE result = selector.visitIn( ref, Arrays.asList( BinaryString.fromString("www.example.com"), BinaryString.fromString("zzz.com"))); Assertions.assertThat(result).isNotEmpty(); // visitBetween should not throw NPE result = selector.visitBetween( ref, BinaryString.EMPTY_UTF8, BinaryString.fromString("zzz.com")); Assertions.assertThat(result).isNotEmpty(); } ``` ### What doesn't meet your expectations? When querying a table with a btree global index on a STRING/VARCHAR column, a NullPointerException is thrown: <img width="2674" height="1932" alt="Image" src="https://github.com/user-attachments/assets/a0c76990-dd78-4dda-a413-653f7c4288ee"; /> ### Anything else? _No response_ ### Are you willing to submit a PR? - [x] I'm willing to submit a PR! -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
