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Path ID Negative 1 and 0 in Execution Engine Profiles

mferrallmferrall Vertica Customer
edited August 2022 in General Discussion

Hello, I've been exploring query profiling, and ran into two Path ID's that I don't see in our Query Explain Plan, 0 and -1.

For 0, I see nodes sending data to a single node, I assume this is where data is sent to the query originator?

However, Path ID -1 is more confusing. For some basic queries, I see 'Root'. Does that account for transfer to the client?

In other queries, for example, in the one below where I force a Merge Join (doing this for understanding, not for production queries), the only sort operation I see occurs in PathId -1. However, I'd expect it to occur on a path id associated with the join. I also see filter operations, which I'd expect to see associated with reading from disk.

My best guess at this moment is that -1 is used for paths that aren't expressed as individual paths, but are 'implied paths', ie the sort operations, filter operation, and root. Is that correct, or does it indicate something else?


  , COUNT(*)
   JOIN /*+JTYPE(FM)*/ dim
        ON fact.account_id = da.account_id
WHERE > '2022-08-01'

Summary of the -1 Path ID in Excel


  • HibikiHibiki Vertica Employee Employee

    @mferrall Thank you for sharing this information. Sort and StorageUnion don't appear in path ID = -1. We will fix it in the future release.

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