[
https://issues.apache.org/jira/browse/SPARK-20233?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Wenchen Fan reassigned SPARK-20233:
-----------------------------------
Assignee: Ioana Delaney
> Apply star-join filter heuristics to dynamic programming join enumeration
> -------------------------------------------------------------------------
>
> Key: SPARK-20233
> URL: https://issues.apache.org/jira/browse/SPARK-20233
> Project: Spark
> Issue Type: Sub-task
> Components: SQL
> Affects Versions: 2.2.0
> Reporter: Ioana Delaney
> Assignee: Ioana Delaney
> Priority: Critical
> Fix For: 2.2.0
>
>
> This JIRA integrates star-join detection with the cost-based optimizer.
> The join enumeration using dynamic programming generates a set of feasible
> joins. The sub-optimal plans can be eliminated by a sequence of independent,
> optional filters. The optional filters include heuristics for reducing the
> search space. For example,
> # Star-join: Tables in a star schema relationship are planned together since
> they are assumed to have an optimal execution.
> # Cartesian products: Cartesian products are deferred as late as possible to
> avoid large intermediate results (expanding joins, in general).
> # Composite inners: “Bushy tree” plans are not generated to avoid
> materializing intermediate result.
> For reference, see “Measuring the Complexity of Join Enumeration in Query
> Optimization” by Ono et al.
> This JIRA implements the star join filter.
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org
For additional commands, e-mail: issues-h...@spark.apache.org
