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https://issues.apache.org/jira/browse/OAK-34?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13245164#comment-13245164
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Thomas Mueller commented on OAK-34:
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> Currently the query needs to be parsed twice.
A query only needs to be parsed twice if the method JCR API method
Query.getBindVariableNames() is used. I guess normally this method isn't used,
as the application already knows the bind variable names.
> The prepare() method would return a pre-parsed query
That's possible, but it would add another interface (Query) which isn't really
necessary most of the time. Also, it wouldn't be necessary to avoid parsing
queries twice (if this is what you are worried about). Instead of passing the
parsed query to oak-jcr, the query engine in oak-core could keep a query cache.
That would also speed up executing repeated queries.
> clients could build queries for their own languages
Currently, the query parsers are within oak-core. If additional query parsers
are required, then I think oak-core is the place where they should be
registered. I would like to avoid exposing the abstract syntax tree to oak-jcr.
> QueryResult which has an inner interface called Row
Sounds good to me, I will change it.
> Result.getRows() should probably return an Iterable
I also thought about that, but I would like to keep it until we have a good use
case for Iterable.
> Maybe Result.getRows() should allow for specifying offset and limit.
Some optimizations might require to know the offset and limit before executing
the query (the easiest optimization is using a limit of 0), therefore I would
like to specify the offset and limit right when executing the query.
> Define query API
> ----------------
>
> Key: OAK-34
> URL: https://issues.apache.org/jira/browse/OAK-34
> Project: Jackrabbit Oak
> Issue Type: New Feature
> Components: core
> Reporter: Michael Dürig
> Labels: query
>
> Define a oak-core API for handling queries. How do we handle name space
> mappings, value bindings, limit, offset, access rights. See OAK-28
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