Details
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Bug
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Status: Patch Available
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Major
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Resolution: Unresolved
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1.8.2
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None
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None
Description
According to http://avro.apache.org/docs/1.8.2/spec.html#Decimal
For the purposes of schema resolution, two schemas that are decimal logical types match if their scales and precisions match.
This is not enforced.
I wrote a file with (precision 5, scale 2) and tried to read it with a reader schema with (precision 3, scale 1). I expected an AvroTypeException to be thrown, but none was thrown.
Test data file attached. The code to read it is:
ReadDecimal.java
import java.io.File;
import org.apache.avro.Schema;
import org.apache.avro.file.DataFileReader;
import org.apache.avro.generic.GenericDatumReader;
import org.apache.avro.generic.GenericRecord;
import org.apache.avro.io.DatumReader;
public class ReadDecimal {
public static void main(String[] args) throws Exception {
Schema schema = new Schema.Parser().parse("{\n" + " \"type\" : \"record\",\n" + " \"name\" : \"some_schema\",\n"
+ " \"namespace\" : \"com.howdy\",\n" + " \"fields\" : [ {\n" + " \"name\" : \"name\",\n"
+ " \"type\" : \"string\"\n" + " }, {\n" + " \"name\" : \"value\",\n" + " \"type\" : {\n"
+ " \"type\" : \"bytes\",\n" + " \"logicalType\" : \"decimal\",\n" + " \"precision\" : 3,\n"
+ " \"scale\" : 1\n" + " }\n" + " } ]\n" + "}");
DatumReader<GenericRecord> datumReader = new GenericDatumReader<>(schema);
// dec.avro has precision 5, scale 2
DataFileReader<GenericRecord> dataFileReader = new DataFileReader<>(
new File("/tmp/dec.avro"), datumReader);
GenericRecord foo = null;
while (dataFileReader.hasNext()) {
foo = dataFileReader.next(foo); // AvroTypeException expected due to change in scale/precision but none occurs
}
}
}
