How do I implement weighting on fulltext search results ?

I'm working on Nuxeo EP 5.6HF29 with Postgresql 9.1. I'm looking for a way to implement weighting on search results based on a multi criteria query. The NXQL query looks like this :

Select * from Document where ecm:fulltext = 'Discipline' or ecm:fulltext_title = 'Discipline'

Nuxeo converts the NXQL query to Postgresql SQL and it looks like that :

SELECT "_C1" FROM(
    SELECT "hierarchy"."id" AS "_C1"
    FROM "hierarchy" JOIN "fulltext" ON "fulltext"."id" = "hierarchy"."id"
    WHERE(
        ("hierarchy"."primarytype" IN ('SectionRoot', 'concours', 'Workspace', 'RelationSearch', 'BlogSite', 'ManagementRoot', 'Tag', 'AdministrativeStatusContainer', 'DocumentRoute', 'Thread', 'search_results', 'Space', 'documentrh', 'TemplateRoot', 'DocumentRouteStep', 'Domain', 'WorkspaceRoot', 'Comment', 'QueryNav', 'ConditionalStepFolder', 'SimpleTask', 'WebPage', 'ConditionalTask', 'StepFolder', 'WCOpenSocial', 'MailMessage', 'Forum', 'ContextualLink', 'PictureBook', 'Unit', 'TaskRoot', 'Post', 'WCHtml', 'DocumentRouteInstancesRoot', 'FollowLifeCycleTransitionTask', 'PublishTask', 'DocumentRouteModelsRoot', 'AdministrativeStatus', 'UserWorkspacesRoot', 'Picture', 'Document', 'Folder', 'WCPicture', 'FacetedSearch', 'RouteNode', 'File', 'AdvancedSearch', 'WebSite', 'FacetedSearchDefault', 'Gadget', 'Note', 'TaskDoc', 'HiddenFolder', 'Section', 'UserProfile', 'MailFolder', 'OrderedFolder', 'BasicAuditSearch', 'CommentRoot', 'BlogPost')
    )
    AND (((TO_TSQUERY('fr', '(Discipline)') @@ NX_TO_TSVECTOR("fulltext"."fulltext"))) OR ((TO_TSQUERY('fr', '(Discipline)') @@ NX_TO_TSVECTOR("fulltext"."fulltext_title"))))
)
UNION ALL
    SELECT "_H"."id" AS "_C1"
    FROM "hierarchy" "_H"
    JOIN "proxies" ON "_H"."id" = "proxies"."id"
    JOIN "hierarchy" ON "proxies"."targetid" = "hierarchy"."id"
    JOIN "fulltext" ON "fulltext"."id" = "hierarchy"."id"
    WHERE (
        ("hierarchy"."primarytype" IN ('SectionRoot', 'concours', 'Workspace', 'RelationSearch', 'BlogSite', 'ManagementRoot', 'Tag', 'AdministrativeStatusContainer', 'DocumentRoute', 'Thread', 'search_results', 'Space', 'documentrh', 'TemplateRoot', 'DocumentRouteStep', 'Domain', 'WorkspaceRoot', 'Comment', 'QueryNav', 'ConditionalStepFolder', 'SimpleTask', 'WebPage', 'ConditionalTask', 'StepFolder', 'WCOpenSocial', 'MailMessage', 'Forum', 'ContextualLink', 'PictureBook', 'Unit', 'TaskRoot', 'Post', 'WCHtml', 'DocumentRouteInstancesRoot', 'FollowLifeCycleTransitionTask', 'PublishTask', 'DocumentRouteModelsRoot', 'AdministrativeStatus', 'UserWorkspacesRoot', 'Picture', 'Document', 'Folder', 'WCPicture', 'FacetedSearch', 'RouteNode', 'File', 'AdvancedSearch', 'WebSite', 'FacetedSearchDefault', 'Gadget', 'Note', 'TaskDoc', 'HiddenFolder', 'Section', 'UserProfile', 'MailFolder', 'OrderedFolder', 'BasicAuditSearch', 'CommentRoot', 'BlogPost'))
        AND (((TO_TSQUERY('fr', '(Discipline)') @@ NX_TO_TSVECTOR("fulltext"."fulltext"))) OR ((TO_TSQUERY('fr', '(Discipline)') @@ NX_TO_TSVECTOR("fulltext"."fulltext_title"))))
    )) AS "_T"
    LIMIT 201 OFFSET 0

I want to rank search results based on the weighting applied on the title and fulltext columns. By specifying two criterias in the query, the Postgresql ranking function disapears (and there is no way to apply the desired weight on each column) For example : Select * from Document where ecm:fulltext = 'Discipline' generates

SELECT "_C1" FROM(
    SELECT "hierarchy"."id" AS "_C1", TS_RANK_CD(NX_TO_TSVECTOR("fulltext"."fulltext"), TO_TSQUERY('fr', '(Discipline)'), 32) AS _nxscore
    FROM "hierarchy" JOIN "fulltext" ON "fulltext"."id" = "hierarchy"."id"
    WHERE(
        ("hierarchy"."primarytype" IN ('SectionRoot', 'concours', 'Workspace', 'RelationSearch', 'BlogSite', 'ManagementRoot', 'Tag', 'AdministrativeStatusContainer', 'DocumentRoute', 'Thread', 'search_results', 'Space', 'documentrh', 'TemplateRoot', 'DocumentRouteStep', 'Domain', 'WorkspaceRoot', 'Comment', 'QueryNav', 'ConditionalStepFolder', 'SimpleTask', 'WebPage', 'ConditionalTask', 'StepFolder', 'WCOpenSocial', 'MailMessage', 'Forum', 'ContextualLink', 'PictureBook', 'Unit', 'TaskRoot', 'Post', 'WCHtml', 'DocumentRouteInstancesRoot', 'FollowLifeCycleTransitionTask', 'PublishTask', 'DocumentRouteModelsRoot', 'AdministrativeStatus', 'UserWorkspacesRoot', 'Picture', 'Document', 'Folder', 'WCPicture', 'FacetedSearch', 'RouteNode', 'File', 'AdvancedSearch', 'WebSite', 'FacetedSearchDefault', 'Gadget', 'Note', 'TaskDoc', 'HiddenFolder', 'Section', 'UserProfile', 'MailFolder', 'OrderedFolder', 'BasicAuditSearch', 'CommentRoot', 'BlogPost')
    )
    AND (((TO_TSQUERY('fr', '(Discipline)') @@ NX_TO_TSVECTOR("fulltext"."fulltext"))))
)
UNION ALL
    SELECT "_H"."id" AS "_C1", TS_RANK_CD(NX_TO_TSVECTOR("fulltext"."fulltext"), TO_TSQUERY('fr', '(Discipline)'), 32) AS _nxscore
    FROM "hierarchy" "_H"
    JOIN "proxies" ON "_H"."id" = "proxies"."id"
    JOIN "hierarchy" ON "proxies"."targetid" = "hierarchy"."id"
    JOIN "fulltext" ON "fulltext"."id" = "hierarchy"."id"
    WHERE (
        ("hierarchy"."primarytype" IN ('SectionRoot', 'concours', 'Workspace', 'RelationSearch', 'BlogSite', 'ManagementRoot', 'Tag', 'AdministrativeStatusContainer', 'DocumentRoute', 'Thread', 'search_results', 'Space', 'documentrh', 'TemplateRoot', 'DocumentRouteStep', 'Domain', 'WorkspaceRoot', 'Comment', 'QueryNav', 'ConditionalStepFolder', 'SimpleTask', 'WebPage', 'ConditionalTask', 'StepFolder', 'WCOpenSocial', 'MailMessage', 'Forum', 'ContextualLink', 'PictureBook', 'Unit', 'TaskRoot', 'Post', 'WCHtml', 'DocumentRouteInstancesRoot', 'FollowLifeCycleTransitionTask', 'PublishTask', 'DocumentRouteModelsRoot', 'AdministrativeStatus', 'UserWorkspacesRoot', 'Picture', 'Document', 'Folder', 'WCPicture', 'FacetedSearch', 'RouteNode', 'File', 'AdvancedSearch', 'WebSite', 'FacetedSearchDefault', 'Gadget', 'Note', 'TaskDoc', 'HiddenFolder', 'Section', 'UserProfile', 'MailFolder', 'OrderedFolder', 'BasicAuditSearch', 'CommentRoot', 'BlogPost'))
        AND (((TO_TSQUERY('fr', '(Discipline)') @@ NX_TO_TSVECTOR("fulltext"."fulltext"))))
    )) AS "_T"
    ORDER BY _nxscore
    LIMIT 201 OFFSET 0

I want to implement a multi criteria query (with custom weights) directly in the Java source code (query based on the official documentation of Postgresql available here : Controlling Text Search) :

SELECT "_C1" FROM(
    SELECT "hierarchy"."id" AS "_C1", TS_RANK_CD('{0.1,0.4,0.6,1.0}', setweight(to_tsvector(coalesce(fulltext_title,'')), 'A') || setweight(to_tsvector(coalesce(fulltext,'')), 'D'), TO_TSQUERY('fr', '(Discipline)')) AS _nxscore
    FROM "hierarchy" JOIN "fulltext" ON "fulltext"."id" = "hierarchy"."id"
    LEFT JOIN "misc" "_F1" ON "hierarchy"."id" = "_F1"."id"
    WHERE (
        ("hierarchy"."primarytype" IN ('SectionRoot', 'concours', 'Workspace', 'RelationSearch', 'BlogSite', 'ManagementRoot', 'Tag', 'AdministrativeStatusContainer', 'DocumentRoute', 'Thread', 'search_results', 'Space', 'documentrh', 'TemplateRoot', 'DocumentRouteStep', 'Domain', 'WorkspaceRoot', 'Comment', 'QueryNav', 'ConditionalStepFolder', 'SimpleTask', 'WebPage', 'ConditionalTask', 'StepFolder', 'WCOpenSocial', 'MailMessage', 'Forum', 'ContextualLink', 'PictureBook', 'Unit', 'TaskRoot', 'Post', 'WCHtml', 'DocumentRouteInstancesRoot', 'FollowLifeCycleTransitionTask', 'PublishTask', 'DocumentRouteModelsRoot', 'AdministrativeStatus', 'UserWorkspacesRoot', 'Picture', 'Document', 'Folder', 'WCPicture', 'FacetedSearch', 'RouteNode', 'File', 'AdvancedSearch', 'WebSite', 'FacetedSearchDefault', 'Gadget', 'Note', 'TaskDoc', 'HiddenFolder', 'Section', 'UserProfile', 'MailFolder', 'OrderedFolder', 'BasicAuditSearch', 'CommentRoot', 'BlogPost'))
        AND ((TO_TSQUERY('fr', '(Discipline)') @@ NX_TO_TSVECTOR("fulltext"."fulltext_title")) OR (TO_TSQUERY('fr', '(Discipline)') @@ NX_TO_TSVECTOR("fulltext"."fulltext")))
)
UNION ALL
    SELECT "_H"."id" AS "_C1", TS_RANK_CD('{0.1,0.4,0.6,1.0}',setweight(to_tsvector(coalesce(fulltext_title,'')), 'A') || setweight(to_tsvector(coalesce(fulltext,'')), 'D'), TO_TSQUERY('fr', '(Discipline)')) AS _nxscore
    FROM "hierarchy" "_H"
    JOIN "proxies" ON "_H"."id" = "proxies"."id"
    JOIN "hierarchy" ON "proxies"."targetid" = "hierarchy"."id"
    JOIN "fulltext" ON "fulltext"."id" = "hierarchy"."id"
    LEFT JOIN "misc" "_F1" ON "hierarchy"."id" = "_F1"."id"
    WHERE (
        ("hierarchy"."primarytype" IN ('SectionRoot', 'concours', 'Workspace', 'RelationSearch', 'BlogSite', 'ManagementRoot', 'Tag', 'AdministrativeStatusContainer', 'DocumentRoute', 'Thread', 'search_results', 'Space', 'documentrh', 'TemplateRoot', 'DocumentRouteStep', 'Domain', 'WorkspaceRoot', 'Comment', 'QueryNav', 'ConditionalStepFolder', 'SimpleTask', 'WebPage', 'ConditionalTask', 'StepFolder', 'WCOpenSocial', 'MailMessage', 'Forum', 'ContextualLink', 'PictureBook', 'Unit', 'TaskRoot', 'Post', 'WCHtml', 'DocumentRouteInstancesRoot', 'FollowLifeCycleTransitionTask', 'PublishTask', 'DocumentRouteModelsRoot', 'AdministrativeStatus', 'UserWorkspacesRoot', 'Picture', 'Document', 'Folder', 'WCPicture', 'FacetedSearch', 'RouteNode', 'File', 'AdvancedSearch', 'WebSite', 'FacetedSearchDefault', 'Gadget', 'Note', 'TaskDoc', 'HiddenFolder', 'Section', 'UserProfile', 'MailFolder', 'OrderedFolder', 'BasicAuditSearch', 'CommentRoot', 'BlogPost'))
        AND ((TO_TSQUERY('fr', '(Discipline)') @@ NX_TO_TSVECTOR("fulltext"."fulltext_title")) OR (TO_TSQUERY('fr', '(Discipline)') @@ NX_TO_TSVECTOR("fulltext"."fulltext")))
    )) AS "_T"
JOIN hierarchy ON hierarchy.id = "_C1"
ORDER BY _nxscore DESC LIMIT 201 OFFSET 0

How do I proceed ?

Thank you for your help. David