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  this work for additional information regarding copyright ownership.
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  (the "License"); you may not use this file except in compliance with
  the License.  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
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  See the License for the specific language governing permissions and
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<!-- The DOCTYPE should be as follows for metadata documents.
<!DOCTYPE jdo
    PUBLIC "-//The Apache Software Foundation//DTD Java Data Objects Metadata 3.2//EN"
    "https://db.apache.org/jdo/xmlns/jdo_3_2.dtd">
-->
<!ELEMENT jdo (extension*, (package|query|fetch-plan)+, extension*)>
<!ATTLIST jdo catalog CDATA #IMPLIED>
<!ATTLIST jdo schema CDATA #IMPLIED>

<!ELEMENT package (extension*, (interface|class|sequence)+, extension*)>
<!ATTLIST package name CDATA ''>
<!ATTLIST package catalog CDATA #IMPLIED>
<!ATTLIST package schema CDATA #IMPLIED>

<!ELEMENT interface (extension*, datastore-identity?, primary-key?, inheritance?, version?, join*, foreign-key*, index*, unique*, property*, query*, fetch-group*, extension*)>
<!ATTLIST interface name CDATA #REQUIRED>
<!ATTLIST interface table CDATA #IMPLIED>
<!ATTLIST interface identity-type (datastore|application|nondurable) #IMPLIED>
<!ATTLIST interface objectid-class CDATA #IMPLIED>
<!ATTLIST interface requires-extent (true|false) 'true'>
<!ATTLIST interface detachable (true|false) 'false'>
<!ATTLIST interface embedded-only (true|false) #IMPLIED>
<!ATTLIST interface catalog CDATA #IMPLIED>
<!ATTLIST interface schema CDATA #IMPLIED>
<!ATTLIST interface cacheable (true|false) 'true'>
<!ATTLIST interface serialize-read (true|false) 'false'>
<!ATTLIST interface use-default-conversion (true|false) 'false'>

<!ELEMENT property (extension*, (array|collection|map)?, join?, embedded?, element?, key?, value?, order?, column*, foreign-key?, index?, unique?, extension*)>
<!ATTLIST property name CDATA #REQUIRED>
<!ATTLIST property persistence-modifier (persistent|transactional|none) #IMPLIED>
<!ATTLIST property default-fetch-group (true|false) #IMPLIED>
<!ATTLIST property load-fetch-group CDATA #IMPLIED>
<!ATTLIST property null-value (default|exception|none) 'none'>
<!ATTLIST property dependent (true|false) #IMPLIED>
<!ATTLIST property embedded (true|false) #IMPLIED>
<!ATTLIST property primary-key (true|false) 'false'>
<!ATTLIST property value-strategy CDATA #IMPLIED>
<!ATTLIST property sequence CDATA #IMPLIED>
<!ATTLIST property serialized (true|false) #IMPLIED>
<!ATTLIST property field-type CDATA #IMPLIED>
<!ATTLIST property table CDATA #IMPLIED>
<!ATTLIST property column CDATA #IMPLIED>
<!ATTLIST property delete-action (restrict|cascade|null|default|none) #IMPLIED>
<!ATTLIST property indexed (true|false|unique) #IMPLIED>
<!ATTLIST property unique (true|false) #IMPLIED>
<!ATTLIST property mapped-by CDATA #IMPLIED>
<!ATTLIST property recursion-depth CDATA #IMPLIED>
<!ATTLIST property field-name CDATA #IMPLIED>
<!ATTLIST property cacheable (true|false) 'true'>
<!ATTLIST property converter CDATA #IMPLIED>
<!ATTLIST property use-default-conversion (true|false) 'false'>

<!ELEMENT class (extension*, implements*, datastore-identity?, primary-key?, inheritance?, version?, join*, foreign-key*, index*, unique*, column*, field*, property*, query*, fetch-group*, extension*)>
<!ATTLIST class name CDATA #REQUIRED>
<!ATTLIST class identity-type (application|datastore|nondurable) #IMPLIED>
<!ATTLIST class objectid-class CDATA #IMPLIED>
<!ATTLIST class table CDATA #IMPLIED>
<!ATTLIST class requires-extent (true|false) 'true'>
<!ATTLIST class persistence-capable-superclass CDATA #IMPLIED>
<!ATTLIST class detachable (true|false) 'false'>
<!ATTLIST class embedded-only (true|false) #IMPLIED>
<!ATTLIST class persistence-modifier (persistence-capable|persistence-aware|non-persistent) #IMPLIED>
<!ATTLIST class catalog CDATA #IMPLIED>
<!ATTLIST class schema CDATA #IMPLIED>
<!ATTLIST class cacheable (true|false) 'true'>
<!ATTLIST class serialize-read (true|false) 'false'>
<!ATTLIST class use-default-conversion (true|false) 'false'>

<!ELEMENT primary-key (extension*, column*, extension*)>
<!ATTLIST primary-key name CDATA #IMPLIED>
<!ATTLIST primary-key column CDATA #IMPLIED>

<!ELEMENT join (extension*, primary-key?, column*, foreign-key?, index?, unique?, extension*)>
<!ATTLIST join table CDATA #IMPLIED>
<!ATTLIST join column CDATA #IMPLIED>
<!ATTLIST join outer (true|false) 'false'>
<!ATTLIST join delete-action (restrict|cascade|null|default|none) #IMPLIED>
<!ATTLIST join indexed (true|false|unique) #IMPLIED>
<!ATTLIST join unique (true|false) #IMPLIED>

<!ELEMENT version (extension*, column*, index?, extension*)>
<!ATTLIST version strategy CDATA #IMPLIED>
<!ATTLIST version column CDATA #IMPLIED>
<!ATTLIST version indexed (true|false|unique) #IMPLIED>

<!ELEMENT datastore-identity (extension*, column*, extension*)>
<!ATTLIST datastore-identity column CDATA #IMPLIED>
<!ATTLIST datastore-identity strategy CDATA 'native'>
<!ATTLIST datastore-identity sequence CDATA #IMPLIED>

<!ELEMENT implements (extension*, property*, extension*)>
<!ATTLIST implements name CDATA #REQUIRED>

<!ELEMENT inheritance (extension*, join?, discriminator?, extension*)>
<!ATTLIST inheritance strategy CDATA #IMPLIED>

<!ELEMENT discriminator (extension*, column*, index?, extension*)>
<!ATTLIST discriminator column CDATA #IMPLIED>
<!ATTLIST discriminator value CDATA #IMPLIED>
<!ATTLIST discriminator strategy CDATA #IMPLIED>
<!ATTLIST discriminator indexed (true|false|unique) #IMPLIED>

<!ELEMENT column (extension*)>
<!ATTLIST column name CDATA #IMPLIED>
<!ATTLIST column target CDATA #IMPLIED>
<!ATTLIST column target-field CDATA #IMPLIED>
<!ATTLIST column jdbc-type CDATA #IMPLIED>
<!ATTLIST column sql-type CDATA #IMPLIED>
<!ATTLIST column length CDATA #IMPLIED>
<!ATTLIST column scale CDATA #IMPLIED>
<!ATTLIST column allows-null (true|false) #IMPLIED>
<!ATTLIST column default-value CDATA #IMPLIED>
<!ATTLIST column insert-value CDATA #IMPLIED>
<!ATTLIST column position CDATA #IMPLIED>

<!ELEMENT field (extension*, (array|collection|map)?, join?, embedded?, element?, key?, value?, order?, column*, foreign-key?, index?, unique?, extension*)>
<!ATTLIST field name CDATA #REQUIRED>
<!ATTLIST field persistence-modifier (persistent|transactional|none) #IMPLIED>
<!ATTLIST field field-type CDATA #IMPLIED>
<!ATTLIST field table CDATA #IMPLIED>
<!ATTLIST field column CDATA #IMPLIED>
<!ATTLIST field primary-key (true|false) 'false'>
<!ATTLIST field null-value (exception|default|none) 'none'>
<!ATTLIST field default-fetch-group (true|false) #IMPLIED>
<!ATTLIST field embedded (true|false) #IMPLIED>
<!ATTLIST field serialized (true|false) #IMPLIED>
<!ATTLIST field dependent (true|false) #IMPLIED>
<!ATTLIST field value-strategy CDATA #IMPLIED>
<!ATTLIST field delete-action (restrict|cascade|null|default|none) #IMPLIED>
<!ATTLIST field indexed (true|false|unique) #IMPLIED>
<!ATTLIST field unique (true|false) #IMPLIED>
<!ATTLIST field sequence CDATA #IMPLIED>
<!ATTLIST field load-fetch-group CDATA #IMPLIED>
<!ATTLIST field recursion-depth CDATA #IMPLIED>
<!ATTLIST field mapped-by CDATA #IMPLIED>
<!ATTLIST field cacheable (true|false) 'true'>
<!ATTLIST field converter CDATA #IMPLIED>
<!ATTLIST field use-default-conversion (true|false) 'false'>

<!ELEMENT foreign-key (extension*, (column* | field* | property*), extension*)>
<!ATTLIST foreign-key table CDATA #IMPLIED>
<!ATTLIST foreign-key deferred (true|false) #IMPLIED>
<!ATTLIST foreign-key delete-action (restrict|cascade|null|default|none) 'restrict'>
<!ATTLIST foreign-key update-action (restrict|cascade|null|default|none) 'restrict'>
<!ATTLIST foreign-key unique (true|false) #IMPLIED>
<!ATTLIST foreign-key name CDATA #IMPLIED>

<!ELEMENT collection (extension*)>
<!ATTLIST collection element-type CDATA #IMPLIED>
<!ATTLIST collection embedded-element (true|false) #IMPLIED>
<!ATTLIST collection dependent-element (true|false) #IMPLIED>
<!ATTLIST collection serialized-element (true|false) #IMPLIED>

<!ELEMENT map (extension)*>
<!ATTLIST map key-type CDATA #IMPLIED>
<!ATTLIST map embedded-key (true|false) #IMPLIED>
<!ATTLIST map dependent-key (true|false) #IMPLIED>
<!ATTLIST map serialized-key (true|false) #IMPLIED>
<!ATTLIST map value-type CDATA #IMPLIED>
<!ATTLIST map embedded-value (true|false) #IMPLIED>
<!ATTLIST map dependent-value (true|false) #IMPLIED>
<!ATTLIST map serialized-value (true|false) #IMPLIED>

<!ELEMENT key (extension*, embedded?, column*, foreign-key?, index?, unique?, extension*)>
<!ATTLIST key column CDATA #IMPLIED>
<!ATTLIST key table CDATA #IMPLIED>
<!ATTLIST key delete-action (restrict|cascade|null|default|none) #IMPLIED>
<!ATTLIST key update-action (restrict|cascade|null|default|none) #IMPLIED>
<!ATTLIST key indexed (true|false|unique) #IMPLIED>
<!ATTLIST key unique (true|false) #IMPLIED>
<!ATTLIST key mapped-by CDATA #IMPLIED>
<!ATTLIST key converter CDATA #IMPLIED>
<!ATTLIST key use-default-conversion (true|false) 'false'>

<!ELEMENT value (extension*, embedded?, column*, foreign-key?, index?, unique?, extension*)>
<!ATTLIST value column CDATA #IMPLIED>
<!ATTLIST value table CDATA #IMPLIED>
<!ATTLIST value delete-action (restrict|cascade|null|default|none) #IMPLIED>
<!ATTLIST value update-action (restrict|cascade|null|default|none) #IMPLIED>
<!ATTLIST value indexed (true|false|unique) #IMPLIED>
<!ATTLIST value unique (true|false) #IMPLIED>
<!ATTLIST value mapped-by CDATA #IMPLIED>
<!ATTLIST value converter CDATA #IMPLIED>
<!ATTLIST value use-default-conversion (true|false) 'false'>

<!ELEMENT array (extension*)>
<!ATTLIST array element-type CDATA #IMPLIED>
<!ATTLIST array embedded-element (true|false) #IMPLIED>
<!ATTLIST array dependent-element (true|false) #IMPLIED>
<!ATTLIST array serialized-element (true|false) #IMPLIED>

<!ELEMENT element (extension*, embedded?, column*, foreign-key?, index?, unique?, extension*)>
<!ATTLIST element column CDATA #IMPLIED>
<!ATTLIST element table CDATA #IMPLIED>
<!ATTLIST element delete-action (restrict|cascade|null|default|none) #IMPLIED>
<!ATTLIST element update-action (restrict|cascade|null|default|none) #IMPLIED>
<!ATTLIST element indexed (true|false|unique) #IMPLIED>
<!ATTLIST element unique (true|false) #IMPLIED>
<!ATTLIST element mapped-by CDATA #IMPLIED>
<!ATTLIST element converter CDATA #IMPLIED>
<!ATTLIST element use-default-conversion (true|false) 'false'>

<!ELEMENT order (extension*, column*, index?, extension*)>
<!ATTLIST order column CDATA #IMPLIED>
<!ATTLIST order mapped-by CDATA #IMPLIED>

<!ELEMENT fetch-group (extension*, (fetch-group|field|property)*, extension*)>
<!ATTLIST fetch-group name CDATA #REQUIRED>
<!ATTLIST fetch-group post-load (true|false) #IMPLIED>

<!ELEMENT fetch-plan (fetch-group*)>
<!ATTLIST fetch-plan name CDATA #REQUIRED>
<!ATTLIST fetch-plan max-fetch-depth CDATA #IMPLIED>
<!ATTLIST fetch-plan fetch-size CDATA #IMPLIED>

<!ELEMENT embedded (extension*, discriminator?, (field|property)*, extension*)>
<!ATTLIST embedded owner-field CDATA #IMPLIED>
<!ATTLIST embedded null-indicator-column CDATA #IMPLIED>
<!ATTLIST embedded null-indicator-value CDATA #IMPLIED>

<!ELEMENT sequence (extension*)>
<!ATTLIST sequence name CDATA #REQUIRED>
<!ATTLIST sequence datastore-sequence CDATA #IMPLIED>
<!ATTLIST sequence factory-class CDATA #IMPLIED>
<!ATTLIST sequence strategy (nontransactional|contiguous|noncontiguous) #REQUIRED>
<!ATTLIST sequence allocation-size CDATA #IMPLIED>
<!ATTLIST sequence initial-value CDATA #IMPLIED>

<!ELEMENT index (extension*, (column* | field* | property*), extension*)>
<!ATTLIST index name CDATA #IMPLIED>
<!ATTLIST index table CDATA #IMPLIED>
<!ATTLIST index unique (true|false) 'false'>

<!ELEMENT query (#PCDATA|extension)*>
<!ATTLIST query name CDATA #REQUIRED>
<!ATTLIST query language CDATA #IMPLIED>
<!ATTLIST query unmodifiable (true|false) 'false'>
<!ATTLIST query unique (true|false) #IMPLIED>
<!ATTLIST query result-class CDATA #IMPLIED>
<!ATTLIST query fetch-plan CDATA #IMPLIED>

<!ELEMENT unique (extension*, (column* | field* | property*), extension*)>
<!ATTLIST unique name CDATA #IMPLIED>
<!ATTLIST unique table CDATA #IMPLIED>
<!ATTLIST unique deferred (true|false) 'false'>

<!ELEMENT extension ANY>
<!ATTLIST extension vendor-name CDATA #REQUIRED>
<!ATTLIST extension key CDATA #IMPLIED>
<!ATTLIST extension value CDATA #IMPLIED>