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Thomas Mueller commented on OAK-4888: ------------------------------------- Documentation in revision 1783902. > Warn or fail queries above a configurable cost value > ---------------------------------------------------- > > Key: OAK-4888 > URL: https://issues.apache.org/jira/browse/OAK-4888 > Project: Jackrabbit Oak > Issue Type: Improvement > Components: query > Reporter: Alexander Klimetschek > Assignee: Thomas Mueller > Labels: docs-impacting > Fix For: 1.5.13, 1.6.0 > > > *Problem:* It's easy to run into performance problems with queries that are > not backed by an index or miss the right one. Developers writing these > queries typically do not have the real large production data, and thus don't > see that a query would scale badly, and would not see any traversal warnings, > as these only happen with a large number of results. > *Proposal:* Oak's query engine already calculates a cost estimate to make a > decision which index to use, or even if there is any at all. This cost > estimate could be used to find out if a query is not supported by an index or > with one that is not suitable enough (e.g. ordering by property that is not > indexed) > If a query is above a certain cost value, a big warning could be put out or > even the query could be made to fail (maybe a per query option, that you > might want to have to "fail" by default to ensure people are not overlooking > the problem). The cost limit should be configurable, as it might depend on > the hardware power. -- This message was sent by Atlassian JIRA (v6.3.15#6346)