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Slow Index Creation, why is it not consuming more memory. - Mailing list pgsql-performance

From Tory M Blue
Subject Slow Index Creation, why is it not consuming more memory.
Date
Msg-id CAEaSS0Zirkg32sea3pUDQSzdxxwQ8DWcNb5v2x2cQiMS-tAKEg@mail.gmail.com
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Responses Re: Slow Index Creation, why is it not consuming more memory.  (Peter Geoghegan <peter.geoghegan86@gmail.com>)
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Just trying to figure something out.

9.3.4, CentOS6.5
256GB Ram

Maintenance_work_mem = 125GB
Effective_Cache = 65GB

I have 2 indexes running, started at the same time, they are not small and one will take 7 hours to complete.

I see almost zero disk access, very minor, not what I want to see when I have an index that will be as large as it is! , but whatever.

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND   

18059 postgres  20   0 5119m 2.4g  20m R 100.0  0.9  12:31.05 postmaster                                               

18091 postgres  20   0 9794m 6.9g  20m R 100.0  2.7  11:41.61 postmaster 

Why are 2 index using different amounts of resident mem, when they have the keys to the castle, and why are they not taking more?

I've tried this with as low as 4GB of maintenance_work_mem and the numbers in TOP stay the same.

Work_mem is 7GB.

What am I not understanding missing?

Thanks
Tory

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