sparql delete query optimization

Question

I have a query delete/insert that I'd like to optimize if possible. The query does delete/insert on up to 50 objects at a time. My Jmeter tests show that the DELETE clause takes 4 times longer in comparison to INSERT: delete takes around 3300 ms and insert takes about 860 ms. I'd like to improve the DELETE clause. I was thinking of using FILTER, but was told it would not scale well. Any recommendation is much appreciated. What I have right now is:

DELETE { 
?s ?p ?o.
?collection dc:identifier  ?cid;
    rdf:type  ?ct;
    rdf:li  ?list.
?list   rdf:first ?first; 
    rdf:rest  ?rest.
} 
WHERE
{
    { ?s dc:identifier "11111"^^xsd:int; ?p ?o. } 
    UNION { ?s dc:identifier "22222"^^xsd:int; ?p ?o.} 
    UNION {?s dc:identifier "33333"^^xsd:int; ?p ?o.} 
    UNION{} UNION{}.......

    OPTIONAL{
        ?s  dc:hasPart ?collection.
        ?collection dc:identifier  ?cid;
            rdf:type    ?ct;
            rdf:li  ?list.
        ?list   rdf:first ?first;
           rdf:rest  ?rest.
}
INSERT DATA 
{
    GRAPH <http://test.org/>
    {.....}
    GRAPH <http://test.org/>
    {.....}
    GRAPH....
}

Answer 1

Without having your data, or even knowing what triple store you're using, we can't really help much in optimization. It might just be that deletes are more expensive than insertions. That said, one thing that might help is to use values rather than unions in your where block. That is, instead of:

{ ?s dc:identifier "11111"^^xsd:int; ?p ?o. } 
UNION { ?s dc:identifier "22222"^^xsd:int; ?p ?o.} 
UNION {?s dc:identifier "33333"^^xsd:int; ?p ?o.} 
UNION{} UNION{}.......

do:

values ?identifier { "11111"^^xsd:int "22222"^^xsd:int "33333"^^xsd:int "44444"^^xsd:int }
?s dc:identifier ?identifier ; ?p ? o