[JENA-2177] The execution of DELETE has extraordinary large latency and RAM

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Information Provided
• Affects Version/s: Jena 4.0.0
• Component/s: ARQ

Environment

Windows 10 
jdk1.8.0_181
jre1.8.0_261
IDE : Eclipse Photon Release (4.8.0)

It occurs in multiple environments.

• Assignee: Unassigned
• Reporter: Hemant Tiwari
• Created: 05/Oct/21 13:14
• Updated: 03/Dec/21 06:54
• Resolved: 07/Oct/21 12:10

Description

Hi,

Issuing a DELETE with 10+  WHERE clauses has a lot of execution latency.

Reproduction Route :
1. Insert a small amount of data (~ 50 Statements)
2. Issue a DELETE with ~ 15 clauses.

Observation:
The execution of DELETE has extraordinary large latency and RAM.

Example of DELETE Query used:

String deleteQuery = "DELETE {\n" +
            "        <http://www.abc.org/2147502238> ?p0 ?o0 .\n" +
            "        <http://www.abc.org/2147502239> ?p1 ?o1 .\n" +
            "        <http://www.abc.org/2147502240> ?p2 ?o2 .\n" +
            "        <http://www.abc.org/2147502241> ?p3 ?o3 .\n" +
            "        <http://www.abc.org/2147502242> ?p4 ?o4 .\n" +
            "        <http://www.abc.org/2147502243> ?p5 ?o5 .\n" +
            "        <http://www.abc.org/2147502244> ?p6 ?o6 .\n" +
            "        <http://www.abc.org/2147502245> ?p7 ?o7 .\n" +
            "        <http://www.abc.org/2147502246> ?p8 ?o8 .\n" +
            "        <http://www.abc.org/2147502247> ?p9 ?o9 .\n" +
            "        <http://www.abc.org/2147502248> ?p10 ?o10 .\n" +
            "        <http://www.abc.org/2147502249> ?p11 ?o11 .\n" +
            "        <http://www.abc.org/2147502250> ?p12 ?o12 .\n" +
            "    }\n" +
            "    WHERE {\n" +
            "        <http://www.abc.org/2147502238> ?p0 ?o0 .\n" +
            "        <http://www.abc.org/2147502239> ?p1 ?o1 .\n" +
            "        <http://www.abc.org/2147502240> ?p2 ?o2 .\n" +
            "        <http://www.abc.org/2147502241> ?p3 ?o3 .\n" +
            "        <http://www.abc.org/2147502242> ?p4 ?o4 .\n" +
            "        <http://www.abc.org/2147502243> ?p5 ?o5 .\n" +
            "        <http://www.abc.org/2147502244> ?p6 ?o6 .\n" +
            "        <http://www.abc.org/2147502245> ?p7 ?o7 .\n" +
            "        <http://www.abc.org/2147502246> ?p8 ?o8 .\n" +
            "        <http://www.abc.org/2147502247> ?p9 ?o9 .\n" +
            "        <http://www.abc.org/2147502248> ?p10 ?o10 .\n" +
            "        <http://www.abc.org/2147502249> ?p11 ?o11 .\n" +
            "        <http://www.abc.org/2147502250> ?p12 ?o12 .\n" +
            "    }\n" 

Investigation :

In org.apache.jena.sparql.modify package UpdateProcessorBase.java function execute()
"Iter.sendToSink(request.iterator(), sink);" seems to be the cause.

With 50 Statements in JENA and above DELETE Query it takes ~ 112 seconds.