A code to reproduce https://github.com/yugabyte/yugabyte-db/issues/18461

YugabyteTest.java

package org.example;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import org.example.ConnectionFactory.Id;

public class YugabyteTest {
  private static class Stats {
    private final ConnectionFactory.Id connFactoryId;

    AtomicInteger insertedCount = new AtomicInteger();
    AtomicInteger deletedCount = new AtomicInteger();
    AtomicInteger selectedCount = new AtomicInteger();
    CopyOnWriteArrayList<Exception> exceptions = new CopyOnWriteArrayList<>();

    public Stats(Id connFactoryId) {
      this.connFactoryId = connFactoryId;
    }

    @Override
    public String toString() {
      return "Stats{" +
          "connFactoryId=" + connFactoryId +
          ", insertedCount=" + insertedCount +
          ", deletedCount=" + deletedCount +
          ", selectedCount=" + selectedCount +
          ", exceptions=" + aggregateExceptions() +
          '}';
    }

    private Map<String, Integer> aggregateExceptions() {
      Map<String, Integer> summary = new HashMap<>();
      exceptions.forEach(ex -> {
          String key = ex.getMessage();
          summary.put(key, summary.computeIfAbsent(key, k -> 0) + 1);
        });
      return summary;
    }
  }

  private void init(ConnectionFactory connFactory) throws SQLException {
    try (Connection conn = connFactory.connect();
        Statement stmt = conn.createStatement()) {
      stmt.execute("CREATE TABLE IF NOT EXISTS float_tbl (pk double precision PRIMARY KEY)");
    }

    try (Connection conn = connFactory.connect();
        Statement stmt = conn.createStatement()) {
      stmt.execute("TRUNCATE TABLE float_tbl");
    }
  }

  private void execute(ConnectionFactory connFactory, Stats stats, float key) throws SQLException {
    try (Connection conn = connFactory.connect();
        PreparedStatement ps = conn.prepareStatement("INSERT INTO float_tbl (pk) VALUES (?)")) {
      ps.setFloat(1, key);
      if (ps.executeUpdate() > 0) {
        stats.insertedCount.incrementAndGet();
      }
    }

    try (Connection conn = connFactory.connect();
        PreparedStatement ps = conn.prepareStatement("DELETE FROM float_tbl WHERE pk = ?")) {
      ps.setFloat(1, key);
      if (ps.executeUpdate() > 0) {
        stats.deletedCount.incrementAndGet();
      }
    }

    try (Connection conn = connFactory.connect();
        PreparedStatement ps = conn.prepareStatement("SELECT pk FROM float_tbl WHERE pk = ?")) {
      ps.setFloat(1, key);
      ResultSet resultSet = ps.executeQuery();
      if (resultSet.next()) {
        stats.selectedCount.incrementAndGet();
      }
    }
  }

  public static void main(String[] args) throws SQLException {
    YugabyteTest yugabyteTest = new YugabyteTest();

    for (ConnectionFactory.Id connFactoryId : Arrays.asList(Id.YUGABYTE, Id.PG, Id.MYSQL)) {
      ConnectionFactory connFactory = ConnectionFactory.of(connFactoryId);

      yugabyteTest.init(connFactory);

      int n = 10000;
      Stats stats = new Stats(connFactoryId);
      Random random = new Random();
      AtomicInteger count = new AtomicInteger();
      random.doubles(n, Float.MIN_VALUE, Float.MAX_VALUE).parallel().forEach(key -> {
        int currentCount = count.getAndIncrement();
        if (currentCount % 1000 == 0) {
          // System.out.println("count: " + currentCount);
        }
        // System.out.println(key);
        try {
          yugabyteTest.execute(connFactory, stats, (float) key);
        }
        catch (Exception e) {
          stats.exceptions.add(e);
          try {
            TimeUnit.MILLISECONDS.sleep(500);
          } catch (InterruptedException ex) {
            throw new RuntimeException(ex);
          }
        }
      });

      System.out.println(stats);
    }
  }
}

STDOUT

Stats{connFactoryId=YUGABYTE, insertedCount=9998, deletedCount=0, selectedCount=9998, exceptions={ERROR: duplicate key value violates unique constraint "float_tbl_pkey"=2}}
Stats{connFactoryId=PG, insertedCount=10000, deletedCount=10000, selectedCount=0, exceptions={}}
Stats{connFactoryId=MYSQL, insertedCount=10000, deletedCount=10000, selectedCount=0, exceptions={}}