[Tutor] string pickling and sqlite blob'ing

[Dinesh B Vadhia]

Hi Vince

That's terrific!  Once a string is compressed with gzip.zlib does it make a difference whether it is stored it in a TEXT or BLOB column?

Dinesh




From: vince spicer 
Sent: Wednesday, June 24, 2009 10:49 AM
To: Dinesh B Vadhia 
Cc: tutor at python.org 
Subject: Re: [Tutor] string pickling and sqlite blob'ing


Pickle is more for storing complex objects (arrays, dict, etc). pickling a string makes it bigger.

I have stored large text chunks in text and/or blob columns compressed with gzip.zlib.compress and extracted with gzip.zlib.decompress

Comparison:

import cPickle as Pickle
import gzip

x = "asdfasdfasdfasdfasdfasdfasdfasdfasdf"

print len(x)
>> 36

print len(Pickle.dumps(x))
>> 44

print len(gzip.zlib.compress(x))
>> 14


Vince


On Wed, Jun 24, 2009 at 11:17 AM, Dinesh B Vadhia <dineshbvadhia at hotmail.com> wrote:

I want to pickle (very long) strings and save them in a sqlite db.  The plan is to use pickle dumps() to turn a string into a pickle object and store it in sqlite.  After reading the string back from the sqlite db, use pickle loads() to turn back into original string.  

- Is this a good approach for storing very long strings?  

- Are the pickle'd strings stored in the sqlite db as a STRING or BLOB? 

Cheers.

Dinesh



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