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https://issues.apache.org/jira/browse/PHOENIX-6412?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Lars Hofhansl updated PHOENIX-6412:
-----------------------------------
Description:
Currently uncovered columns are merged row-by-row, performing a Get to the data
region for each matching row in the index region.
Each Get needs to seek all the store scanners, and doing this per row is quite
expensive.
Instead we could batch inside the RegionScannerFactory.getWrappedScanner() ->
RegionScanner.nextRaw() method. Collect N index rows and then execute a single
skip scan.
I might be able to get to that, but there's someone who is interested in taking
this up I would not mind :)
was:
Currently uncovered columns are merge row-by-row performing a Get to the data
region for each matching row in the index region.
Each Get needs to seek all the store scanners, and doing this per row is quite
expensive.
Instead we could batch inside the RegionScannerFactory.getWrappedScanner() ->
RegionScanner.nextRaw() method. Collect N index rows and then execute a skip
scan.
I might be able to get to that, but there's someone who is interested in taking
this up I would not mind :)
> Consider batching uncovered column merge for local indexes
> ----------------------------------------------------------
>
> Key: PHOENIX-6412
> URL: https://issues.apache.org/jira/browse/PHOENIX-6412
> Project: Phoenix
> Issue Type: Improvement
> Reporter: Lars Hofhansl
> Priority: Minor
> Fix For: 5.2.0
>
>
> Currently uncovered columns are merged row-by-row, performing a Get to the
> data region for each matching row in the index region.
> Each Get needs to seek all the store scanners, and doing this per row is
> quite expensive.
> Instead we could batch inside the RegionScannerFactory.getWrappedScanner() ->
> RegionScanner.nextRaw() method. Collect N index rows and then execute a
> single skip scan.
> I might be able to get to that, but there's someone who is interested in
> taking this up I would not mind :)
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