multi-term search the default "OR" in Confluence 5.2.x, 5.3.x.

multi-term search the default "OR" in Confluence 5.2.x, 5.3.x.
Please confirm the following test results.

Test Results (5.3.x)

Query: Confluence Search
https://confluence.atlassian.com/dosearchsite.action?queryString=Confluence%20Search&startIndex=0&where=conf_all
Page 1 of 5479. Showing 54782 results

Query: Confluence OR Search
https://confluence.atlassian.com/dosearchsite.action?queryString=Confluence%20OR%20Search&startIndex=0&where=conf_all
Page 1 of 5479. Showing 54782 results

Query: Confluence AND Search
https://confluence.atlassian.com/dosearchsite.action?queryString=Confluence%20AND%20Search&startIndex=0&where=conf_all
Page 1 of 639. Showing 6390 results

Query: +Confluence +Search
https://confluence.atlassian.com/dosearchsite.action?queryString=%2BConfluence%20%2BSearch&startIndex=0&where=conf_all
Page 1 of 639. Showing 6390 results

Confirmation

Is this specifications change?
Can this be changed by setting?
We want to make a default AND.

https://confluence.atlassian.com/display/DOC/Confluence+5.2+Release+Notes
Confluence 5.2.x versionup Lucene ver 4.3.0.
Is it the influence?

I confirm "AND search" in Confluence version 4.x.
I think that it was the following issues.
https://jira.atlassian.com/browse/CONF-5874

Appendix:

QueryParser.setDefaultOperator(QueryParser.Operator.AND);
ref. http://lucene.apache.org/core/4_3_0/queryparser/org/apache/lucene/queryparser/classic/QueryParser.Operator.html