Eav\AbstractEntity.php

<?php
namespace Db\Benchmark\Domain\Model\Eav;

/*                                                                        *
 * This script belongs to the TYPO3 Flow package "Db.Benchmark".          *
 *                                                                        *
 *                                                                        */

use Doctrine\Common\Collections;
use TYPO3\Flow\Annotations as Flow;
use Doctrine\ORM\Mapping as ORM;

/**
 * An Entity which contains dynamic attributes via the EAV pattern.
 *
 * @ORM\MappedSuperclass
 */
abstract class AbstractEntity {

	/**
	 * @var \Doctrine\Common\Collections\Collection<EntityAttribute>
	 * @ORM\ManyToMany(orphanRemoval=true, cascade={"ALL"}, indexBy="name")
	 * @ORM\JoinTable(inverseJoinColumns={@ORM\JoinColumn(unique=true)})
	 */
	protected $additionalAttributes;

	public function __construct() {
		$this->additionalAttributes = new \Doctrine\Common\Collections\ArrayCollection();
	}

	/**
	 * Magic setter and getter implementation for Eav Entity Attributes
	 * 
	 * @param string $method
	 * @param array $arguments
	 * @throws \InvalidArgumentException
	 * @return mixed
	 */
	public function __call($method, $arguments) {
		...
	}
}
?>

Eav\EntityAttribute.php

<?php
namespace Db\Benchmark\Domain\Model\Eav;

/*                                                                        *
 * This script belongs to the TYPO3 Flow package "Db.Benchmark".          *
 *                                                                        *
 *                                                                        */

use TYPO3\Flow\Annotations as Flow;
use Doctrine\ORM\Mapping as ORM;

/**
 * An entity attribute that can contain dynamic datatype values
 *
 * TODO: This should be an abstract mapped superclass instead
 * @Flow\Entity
 */
class EntityAttribute {

	/**
	 * The name
	 * @var string
	 * @ORM\Id
	 */
	protected $name;

	/**
	 * The type
	 * @var string
	 * @ORM\Column(length=16)
	 */
	protected $type;

	/**
	 * The value
	 * @var string
	 * @ORM\Column(type="text")
	 */
	protected $value;

	/**
	 * @param string $name
	 * @param mixed $value
	 * @param string $type
	 * @throws \InvalidArgumentException
	 */
	public function __construct($name, $value, $type = NULL) {
		..
	}
	
	..
}
?>

EavEntity.php

<?php
namespace Db\Benchmark\Domain\Model;

/*                                                                        *
 * This script belongs to the TYPO3 Flow package "Db.Benchmark".          *
 *                                                                        *
 *                                                                        */

use TYPO3\Flow\Annotations as Flow;
use Doctrine\ORM\Mapping as ORM;

/**
 * @Flow\Entity
 */
class EavEntity extends Eav\AbstractEntity {

    .. some standard properties
}

With these annotations:
#1295973082: No class schema found for "Db\Benchmark\Domain\Model\Eav\AbstractEntity"

With @flow\Entity in Eav\AbstractEntity:
#1367592354: Method "Flow_Aop_Proxy_buildMethodsAndAdvicesArray" on class "Db\Benchmark\Domain\Model\EavEntity" is not defined.

@flow\Proxy(false) all classes (no AOP/DI needed):
Entity 'Db\Benchmark\Domain\Model\Eav\AbstractEntity' has no method 'Flow_Aop_Proxy_fixMethodsAndAdvicesArrayForDoctrineProxies' to be registered as lifecycle callback.

-> FlowAnnotationDriver always registers fix* lifecycle callbacks even when entity is unproxied, which is not needed, as the fixes only deal with AOP/DI behaviour, which is not expected to work on unproxied classes.