Re: pgbench - allow to specify scale as a size

On 2/20/18 05:06, Fabien COELHO wrote:
>> Now the overhead is really 60-65%. Although the specification is unambiguous,
>> but we still need some maths to know whether it fits in buffers or memory...
>> The point of Karel regression is to take this into account.
>>
>> Also, whether this option would be more admissible to Tom is still an open
>> question. Tom?
>
> Here is a version with this approach: the documentation talks about
> "actual data size, without overheads", and points out that storage
> overheads are typically an additional 65%.

I think when deciding on a size for a test database for benchmarking,
you want to size it relative to RAM or other storage layers. So a
feature that allows you to create a database of size N but it's actually
not going to be anywhere near N seems pretty useless for that.

(Also, we have, for better or worse, settled on a convention for byte
unit prefixes in guc.c. Let's not introduce another one.)

--
Peter Eisentraut http://www.2ndQuadrant.com/
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