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https://issues.apache.org/jira/browse/OPTIQ-302?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Julian Hyde updated OPTIQ-302:
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Fix Version/s: 0.8
> Use heuristic rule to plan queries with large numbers of joins
> --------------------------------------------------------------
>
> Key: OPTIQ-302
> URL: https://issues.apache.org/jira/browse/OPTIQ-302
> Project: Optiq
> Issue Type: Bug
> Reporter: GitHub Import
> Labels: github-import
> Fix For: 0.8
>
>
> If a query has a large number of joins, the planning time and space grows
> exponentially in N, the number of joins. About about N=8 it is not possible
> to plan a query exhaustively.
> `LoptOptimizeJoinRule` is a heuristic join rule that uses a greedy algorithm.
> It operates on a `MultiJoinRel`, which must first have been created using
> `ConvertMultiJoinRule`. Enabling this rule, and disable the join
> transformation rules `SwapJoinRule` and `PushJoinThroughJoinRule`, it is
> possible to plan queries with N=60 and higher.
> ---------------- Imported from GitHub ----------------
> Url: https://github.com/julianhyde/optiq/issues/302
> Created by: [julianhyde|https://github.com/julianhyde]
> Labels:
> Created at: Wed Jun 18 03:27:16 CEST 2014
> State: open
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