[SOLR-805] DisMax queries are not being cached in QueryResultCache

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 1.3
• Fix Version/s: 1.4
• Component/s: search

Environment

Using Sun JDK 1.5 and Solr 1.3.0 release on Windows XP

• Assignee: Unassigned
• Reporter: Todd Feak
• Created: 08/Oct/08 22:53
• Updated: 13/Aug/09 14:03
• Resolved: 24/Oct/08 14:15

Description

I have a DisMax Search Handler set up in my solrconfig.xml to weight results based on which field a hit was found in. Results seem to be coming back fine, but the exact same query issued twice will not result in a cache hit.

I have run far enough in the debugger to determine that the hashCode for the BooleanQuery object is returning a different value each time for the same query. This leads me to believe there is some random factor involved in it's calculation, such as a default Object hashCode() implementation somewhere in the chain. Non DisMax queries seem to be caching just fine.

Where I see this behavior exhibited is on line 47 of the QueryResultKey constructor. I have not dug in far enough to determine exactly where the hashCode is being incorrectly calculated. I will try and dig in further tomorrow, but wanted to get some attention on the bug.

Issue Links

• relates to: LUCENE-1415 MultiPhraseQuery has incorrect hashCode() implementation - Leads to Solr Cache misses