Re: PG as in-memory db? How to warm up and re-populate buffers? How to read in all tuples into memory? - Mailing list pgsql-performance

From Stefan Keller
Subject Re: PG as in-memory db? How to warm up and re-populate buffers? How to read in all tuples into memory?
Date
Msg-id CAFcOn28PmJxWAvZXbakvuXnpJ+VZSdqmWzOo3hf5fc4zCsutvg@mail.gmail.com
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In response to Re: PG as in-memory db? How to warm up and re-populate buffers? How to read in all tuples into memory?  (Jeff Janes <jeff.janes@gmail.com>)
Responses Re: PG as in-memory db? How to warm up and re-populate buffers? How to read in all tuples into memory?
List pgsql-performance
2012/2/29 Jeff Janes <jeff.janes@gmail.com>:
>> It's quite possible the vacuum full is thrashing your disk cache due
>> to maintainance_work_mem. You can overcome this issue with the tar
>> trick, which is more easily performed as:
>>
>> tar cf /dev/null $PG_DATA/base
>
> But on many implementations, that will not work.  tar detects the
> output is going to the bit bucket, and so doesn't bother to actually
> read the data.

Right.
But what about the commands cp $PG_DATA/base /dev/null or cat
$PG_DATA/base > /dev/null ?
They seem to do something.

-Stefan

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