Optimize concurrent queries
---------------------------
Key: JCR-2025
URL: https://issues.apache.org/jira/browse/JCR-2025
Project: Jackrabbit Content Repository
Issue Type: Improvement
Components: jackrabbit-core
Reporter: Marcel Reutegger
Priority: Minor
There are a number of bottlenecks that prevent scalability of concurrent
queries:
- Take norms are created repeatedly because a new
SearchIndex$CombinedIndexReader is created for each query. This prevents
caching of fake norms on the level of the CombinedIndexReader. Creating fake
norms for index readers that span multiple sub reader is inefficient and should
be avoided. Like with other Jackrabbit specific queries, there should be one
for TermQuery, which is aware of sub readers. Its weight should then create one
scorer for each sub reader. This effectively reuses the fake norms on the sub
reader.
- There should be a UUID cache that maps document number to UUID. This is
basically the inverse of the existing DocNumberCache. UUID lookup is regularly
a bottleneck in the SegmentReader where the method document() is synchronized
and does I/O.
- Queries often contain constraints that limit the result to nodes with a
certain flag set to a literal. These constraints should be cached in the query
handler.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
