[Bug] Precision Loss in castFromStringInternal for Valid Float Values (e.g., -0.0009163)

[hunshenshi]

Search before asking

• I searched in the issues and found nothing similar.

Paimon version

paimon-flink-1.18-1.0-SNAPSHOT.jar

Compute Engine

flink

Minimal reproduce step

create table in mysql

CREATE TABLE `example_table` (
  `id` bigint NOT NULL,
  `value` float DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci

and insert data

INSERT INTO example_table (id, value) VALUES (1, -0.0009163);

What doesn't meet your expectations?

Float f = Float.valueOf(s);
if (f.toString().length() != s.length()) {
    throw new NumberFormatException(
            s + " cannot be cast to float due to precision loss");
} else {
    return f;
}

Precision checking should not strictly rely on comparing the lengths of the values. As a result, values such as -0.0009163 and similar ones, which can be safely represented in MySQL FLOAT, are mistakenly rejected.

Anything else?

No response

Are you willing to submit a PR?

• I'm willing to submit a PR!

[hunshenshi]

@herefree can you help me review this? thank you.