[OAK-9423] JCR_SQL2 with ISCHILDNODE slow performance on large Repository

• Type: Bug
• Status: Open
• Priority: Critical
• Resolution: Unresolved
• Component/s: core
• Assignee: Unassigned
• Reporter: Aliaksei
• Created: 04/May/21 15:42
• Updated: 25/May/21 13:01

Description

Very simple query 

 

select n.* from [nt:hierarchyNode] as n where ISCHILDNODE(n, '/myfolder');

Executed up to 40 seconds on Repository with ~5000 files and ~7000 folders. When similar query on the same repo

 

 

select n.* from [nt:hierarchyNode] as n where ISDESCENDANTNODE(n, '/myfolder')

took only ~20ms.

 

According to logs it looks like query with ISCHILDNODE traversing all repository - not only "/myfolder" but all the rest folders.

I found myself that problem might be in 

org.apache.jackrabbit.oak.plugins.index.property.strategy.ContentMirrorStoreStrategy:PathIterator

 

PathIterator(Filter filter, String indexName, String pathPrefix, boolean prependPathPrefix) {
    this.filter = filter;
    this.pathPrefix = pathPrefix;
    this.indexName = indexName;
    boolean shouldDescendDirectly = filter.getPathRestriction().equals(Filter.PathRestriction.ALL_CHILDREN);

 

I'm pretty sure that shouldDescendDirectly should be true also for .DIRECT_CHILDREN.

I even tested it in debug mode and changed value in runtime. Query executed correctly with acceptable speed.