IBX-8019: Added performance consideration notice to LocationService::loadLocationChildren

[webhdx]

Question	Answer
JIRA issue	IBX-8019
Type	improvement
Target Ibexa version	v3.3
BC breaks	no

#401 fixed the issue but some performance related issues became apparent. Due to current database schema shape we cannot provide further optimizations. In cases where there are many children, the query has to fetch all records and join version and language tables. This becomes even worse when Permission criterions are applied adding even more JOINs to the query. Test example from the ticket causes 100000 locations to be loaded which is necessary to perform location sort. This is where majority of query time comes from.

The recommendation is to use SearchService::findLocations instead of LocationService::loadLocationChildren where possible. I've added a notice to the method in order to warn people about potential performance issues.

Existing \eZ\Publish\Core\QueryType\BuiltIn\ChildrenQueryType can be used instead of manually creating the query for SearchService.

Related PRs:

• IBX-8019: Added performance consideration notice to LocationService::loadLocationChildren #407
• IBX-8019: Replaced LocationService::loadLocationChildren use with SearchService ezplatform-admin-ui#2119
• IBX-8019: Replaced LocationService::loadLocationChildren usages with SearchService::findLocations ezrecommendation-client#114

Checklist:

• Provided PR description.
• Tested the solution manually.
• Provided automated test coverage.
• Checked that target branch is set correctly (master for features, the oldest supported for bugs).
• Ran PHP CS Fixer for new PHP code (use $ composer fix-cs).
• Asked for a review (ping @ezsystems/engineering-team).

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarCloud

[tomaszszopinski]

QA approved on IbexaDXP exp 3.3.37.