Re: [psycopg] OT? plpython2u

On 10/21/2016 10:24 AM, Emanuel Calvo wrote:
>
>
> Hey Nahum,
>
> you may want to do that update in batches using id ranges. Also, should
> avoid the
> single transaction method if you have replicas.
>
> BTW, don't know why we are speaking in english, as this is an _español_
> mailing list. Just heads up. :)

Probably because this started on the psycopg list and was Cc'ed to pgsql-es-ayuda:

https://www.postgresql.org/message-id/CABqArLimjV5Binh33sw2C8EV%3Dp_fJstrAj-OCR0%2BGT_MX-JhhA%40mail.gmail.com

>
> Regards,
>
> On Thu, Oct 20, 2016 at 10:27 PM Nahum Castro <nahumcastro(at)gmail(dot)com
> <mailto:nahumcastro(at)gmail(dot)com>> wrote:
>
> At last here is the solution to resize images on bytea columns with
> plpythonu
> Thanks to all especially to Adrian
>
> CREATE OR REPLACE FUNCTION public.ajustar(randstring bytea)
> RETURNS bytea
> LANGUAGE plpythonu
> AS $function$
> from io import BytesIO
> import PIL
> from PIL import Image
> basewidth = 300
> mem_file = BytesIO()
> mem_file.write(randstring)
> img = Image.open(mem_file)
> wpercent = (basewidth/float(img.size[0]))
> hsize = int((float(img.size[1])*float(wpercent)))
> img = img.resize((basewidth,hsize), PIL.Image.ANTIALIAS)
> salida = io.BytesIO
> img.save(salida, format='JPEG')
> hex_data = output.getvalue()
> img.close()
> return hex_data
> $function$
>
> And here is how to resize all images from database:
>
> update personal set foto=ajustar(foto) where foto is not null;
>
> 2016-10-20 19:48 GMT-05:00 Nahum Castro <nahumcastro(at)gmail(dot)com
> <mailto:nahumcastro(at)gmail(dot)com>>:
>
> As far as I know the process to resize the image is:
>
> read(bytea) -> load_to_memory(image) -> resize(image) ->
> recode_to_bytea(image) -> store(bytea)
>
> You helped me with the first two.
>
> When I run the function ajustar(image)
> update personal set image=ajustar(image)
>
> I tried to do a direct resizing from bytea but python can't
> understand the hexadecimal data from bytea as an jpeg image.
> Though I tried with with plpython2u.
> Thanks
>
> 2016-10-20 19:00 GMT-05:00 Adrian Klaver
> <adrian(dot)klaver(at)aklaver(dot)com <mailto:adrian(dot)klaver(at)aklaver(dot)com>>:
>
> On 10/20/2016 04:51 PM, Nahum Castro wrote:
>
> Hello Adrian.
>
> The result image to replace the big one.
>
>
> So if you are replacing the data in a bytea column with a
> function that returns bytea, why encode it?
>
> Unless I am missing something why not just UPDATE with the
> raw(bytea) return value?
>
>
> I have a table with images @ 12K but, went on vacation
> an when returned
> someone replaced the pictures with high resolution
> images @6M. The app
> then become very slow and halted.
>
> I have already made the script in python to resize all
> the images from a
> folder before to upload to the database, so it occurred
> to me do the
> same but on the database.
>
> Thanks again.
>
> 2016-10-20 18:32 GMT-05:00 Adrian Klaver
> <adrian(dot)klaver(at)aklaver(dot)com
> <mailto:adrian(dot)klaver(at)aklaver(dot)com>
> <mailto:adrian(dot)klaver(at)aklaver(dot)com
> <mailto:adrian(dot)klaver(at)aklaver(dot)com>>>:
>
> On 10/20/2016 02:42 PM, Nahum Castro wrote:
>
> Hello,
>
> The script always returns.
> select encode(ajustar(foto), 'escape') from
> personal where id=193;
> encode
>
> -----------------------------------------------------------------
> <PIL.Image.Image image mode=RGB size=300x347 at
> 0x7F08A11B1650>
>
>
>
> So what do you want it to return a where do you want
> to return?
>
>
> --
> Adrian Klaver
> adrian(dot)klaver(at)aklaver(dot)com
> <mailto:adrian(dot)klaver(at)aklaver(dot)com>
> <mailto:adrian(dot)klaver(at)aklaver(dot)com
> <mailto:adrian(dot)klaver(at)aklaver(dot)com>>
>
>
>
>
> --
> *Nahum Castro González*
> Blvd. Perdigón 214, Brisas del Lago.
> CP 37207
> León, Guanajuato, México
> Tel (477)1950304
> Cel (477)1274694
>
>
>
> --
> Adrian Klaver
> adrian(dot)klaver(at)aklaver(dot)com <mailto:adrian(dot)klaver(at)aklaver(dot)com>
>
>
>
>
> --
> *Nahum Castro González*
> Blvd. Perdigón 214, Brisas del Lago.
> CP 37207
> León, Guanajuato, México
> Tel (477)1950304
> Cel (477)1274694
>
>
>
>
> --
> *Nahum Castro González*
> Blvd. Perdigón 214, Brisas del Lago.
> CP 37207
> León, Guanajuato, México
> Tel (477)1950304
> Cel (477)1274694
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com

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