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https://issues.apache.org/jira/browse/CMIS-896?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14349187#comment-14349187
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Nicolas Brandt commented on CMIS-896:
-------------------------------------

I don't doubt that there is a better way to do it than the one I submitted :).

And yes, we could provide cmis:objectTypeId but, unless I misunderstood the 
spec, it is only allowed in this case (section 2.1.14.1.3 of the spec) :
{quote}
If the select clause of the query statement contains properties from a single 
type reference then the repository
MAY represent these pseudo-objects with additional object information.
{quote}

So we can't do that for query like this one :\\
{noformat}select doc.cmis:objectId, sec.aProperty from cmis:document doc inner 
join aSecondaryType sec on sec.cmis:objectId = doc.cmis:objectId{noformat}

And even if the end user add {{doc.cmis:objectTypeId}} into the SELECT clause 
of the previous query, the performance slowdown is still here because of 
{{sec.aProperty}}.

> Improve how JSON response of CMIS query function is built
> ---------------------------------------------------------
>
>                 Key: CMIS-896
>                 URL: https://issues.apache.org/jira/browse/CMIS-896
>             Project: Chemistry
>          Issue Type: Improvement
>          Components: opencmis-server
>    Affects Versions: OpenCMIS 0.12.0
>            Reporter: Nicolas Brandt
>            Assignee: Florian Müller
>            Priority: Minor
>         Attachments: query.patch
>
>
> JSON responses of CMIS queries seems to be built in an inefficient way.
> {code:java|title=org.apache.chemistry.opencmis.commons.impl.JSONConverter.java}
>     /**
>      * Converts a bag of properties.
>      */
>     public static JSONObject convert(final Properties properties, final 
> String objectId, final TypeCache typeCache,
>             final PropertyMode propertyMode, final boolean succinct, final 
> DateTimeFormat dateTimeFormat) {
>         if (properties == null) {
>             return null;
>         }
>         // get the type
>         TypeDefinition type = null;
>         if (typeCache != null) {
>             PropertyData<?> typeProp = 
> properties.getProperties().get(PropertyIds.OBJECT_TYPE_ID);
>             if (typeProp instanceof PropertyId) {
>                 String typeId = ((PropertyId) typeProp).getFirstValue();
>                 if (typeId != null) {
>                     type = typeCache.getTypeDefinition(typeId);
>                 }
>             }
>             if (type == null && objectId != null && propertyMode != 
> PropertyMode.CHANGE) {
>                 type = typeCache.getTypeDefinitionForObject(objectId);
>             }
>         }
>         JSONObject result = new JSONObject();
>         for (PropertyData<?> property : properties.getPropertyList()) {
>             assert property != null;
>             assert property.getId() != null;
>             PropertyDefinition<?> propDef = null;
>             if (typeCache != null) {
>                 propDef = typeCache.getPropertyDefinition(property.getId());
>             }
>             if (propDef == null && type != null) {
>                 propDef = type.getPropertyDefinitions().get(property.getId());
>             }
>             if (propDef == null && typeCache != null && objectId != null && 
> propertyMode != PropertyMode.CHANGE) {
>                 typeCache.getTypeDefinitionForObject(objectId);
>                 propDef = typeCache.getPropertyDefinition(property.getId());
>             }
>             String propId = (propertyMode == PropertyMode.QUERY ? 
> property.getQueryName() : property.getId());
>             if (propId == null) {
>                 throw new CmisRuntimeException("No query name or alias for 
> property '" + property.getId() + "'!");
>             }
>             result.put(propId, convert(property, propDef, succinct, 
> dateTimeFormat));
>         }
>         return result;
>     }
> {code}
> According to the quoted source code, building the JSON response of query 
> {{select cmis:objectId, cmis:name from cmis:document}} requires to call the 
> function ObjectService.getObjectById per each row returned.
> When the query returns 1000 rows and the CMIS server is backed with a 
> database it causes a significant performance slowdown.
> For example with the two following queries (each of them returns 1000 rows):
>  bq. select * from cmis:document
>  bq. select cmis:objectId, cmis:name from cmis:document
> The second one is more than 5x slower than the first one.
> A solution may be to add PropertyType and Cardinality informations into 
> PropertyData objects, so it's no longer necessary to retrieve properties 
> definitions.
> I have attached a svn diff file with the changes.



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