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From:Janek Bogucki Date:May 11 2009 11:15am
Subject:Re: Unix compress equivalent
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Hi Olaf,

If you only need to compress the column *while* loading it from the csv file then use load
data infile with a user variable to do the compression at load time,.

mysql> create table t(uncompressed varchar(4000), compressed varbinary(1000));
Query OK, 0 rows affected (0.07 sec)

mysql> \! echo -e 'abcde\nfghijk\n' > /tmp/test.csv

mysql> load data infile '/tmp/test.csv' into table t (@raw) set uncompressed = @raw,
> compressed = compress(@raw);
Query OK, 3 rows affected (0.00 sec)
Records: 3  Deleted: 0  Skipped: 0  Warnings: 0

mysql> select uncompressed, @a:=hex(compress(uncompressed)), @b:=hex(compressed), @a =
> @b from t;
+--------------+--------------------------------------+--------------------------------------+---------+
| uncompressed | @a:=hex(compress(uncompressed))      | @b:=hex(compressed)               
  | @a = @b |
+--------------+--------------------------------------+--------------------------------------+---------+
| abcde        | 05000000789C4B4C4A4E49050005C801F0   | 05000000789C4B4C4A4E49050005C801F0
  |       1 |
| fghijk       | 06000000789C4B4BCFC8CCCA060008870274 |
06000000789C4B4BCFC8CCCA060008870274 |       1 |
|              |                                      |                                   
  |       1 |
+--------------+--------------------------------------+--------------------------------------+---------+
3 rows in set (0.04 sec)


Cheers,
-Janek

On Fri, 2009-05-08 at 12:29 -0400, Olaf Stein wrote:
> Hi all
> 
> What is the equivalent in unix (more specifically python) to the compress()
> function.
> 
> I am trying to make csv file for use with load data infile and am wondering
> how to compress the strings that I would usually compress with compress() in
> a regular sql statement. The field I am writing this into is longblob and I
> need the compressed version here to be identical to what compress() would do
> 
> Thanks
> olaf
> 
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Thread
Unix compress equivalentOlaf Stein8 May
  • Re: Unix compress equivalentOlaf Stein8 May
    • Re: Unix compress equivalentwalter harms10 May
  • Re: Unix compress equivalentJanek Bogucki11 May
    • Re: Unix compress equivalentOlaf Stein11 May