Re: binary representation of datatypes - Mailing list pgsql-hackers

From Matthieu Imbert
Subject Re: binary representation of datatypes
Date
Msg-id 48FED64D.1000502@ens-lyon.fr
Whole thread Raw
In response to Re: binary representation of datatypes  (Jeroen Vermeulen <jtv@xs4all.nl>)
Responses Re: binary representation of datatypes
Re: binary representation of datatypes
List pgsql-hackers
Jeroen Vermeulen wrote:
> Matthieu Imbert wrote:
> 
>> scenario 1 - parse the textual representation of all results of
>> requests to the database and convert textual timestamps to a binary
>> format that i choose among those ones (number of microseconds since
>> 2000-01-01, or a structure similar to pg_tm (but with
>> microsecond precision), or a time-format similar to one defined in
>> rfc1305, or something else)
>>
>> or
>>
>> scenario 2 - directly use pgsql binary timestamp format. I think the
>> latter is far more efficient. I'm new to postgresql, but from
>> what i understand, here are the conversions involved in both scenarios
>> (hopping that my ascii art won't be garbled by your mail
>> clients ;-) :
>>
>>
>> scenario 1:
>> .---------.  .----------.  .---------.  .----------.  .--------------.  .----------.  .---------.
>> |timestamp|  |pgsql     |  |timestamp|  |pgsql     |  |timestamp     |  |my        |  |my       |
>> |storage  |->|internal  |->|storage  |->|network   |->|as            |->|timestamp |->|timestamp|
>> |in       |  |to        |  |in       |  |to        |  |textual       |  |conversion|  |format   |
>> |database |  |network   |  |network  |  |textual   |  |representation|  |routines  |  |         |
>> |backend  |  |conversion|  |         |  |conversion|  |              |  |          |  |         |
>> |         |  |function  |  |         |  |function  |  |              |  |          |  |         |
>> '---------'  '----------'  '---------'  '----------'  '--------------'  '----------'  '---------'
> 
> I think this scenario has two boxes too many.  Why would the backend
> convert to network representation before converting to text?
> 
> 
> Jeroen
> 

You mean that when results are asked in textual representation (the default), data is sent on network directly as
text?

-- 
Matthieu


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