[JENA-1988] Separating B+ tree into different Node representations.

• Type: Question
• Status: Closed
• Priority: Major
• Resolution: Information Provided
• Affects Version/s: Jena 3.16.0
• Fix Version/s: Jena 3.16.0
• Component/s: TDB
• Labels: features newbie performance test
• Assignee: Andy Seaborne
• Reporter: Martin Pekár
• Created: 29/Oct/20 19:06
• Updated: 17/Apr/21 17:25
• Resolved: 20/Jan/21 18:15

Description

In a project to optimize the indexing, I am trying to have 4 indexes, one for each Node type (variable, literal, URI and blank). To implement this, I added 4 copies of the nodeHashToId Index instance in the NodeTableNative class. Then, for every operation on the nodeHashToId, for example using containsNode() in the NodeTableNative class, I first check the type of Node given as parameter and then check for existence in the appropriate nodeHashToId copy.

Now, for some reason I get a NullPointerException when running the tests. Many of these exceptions appear in the BufferChannelFile class in the size() method because the call to file.channel() return null.

My question is then, is NodeTableNative__ even the right place to implement this optimization, and second, if it is the right place to implement, can you help me understand why this exception is thrown?