Re: [cx-oracle-users] Bug/report cx_Oracle

[Anthony T. <an...@co...>]

If you are referring to this situation:

import cx_Oracle

connection = cx_Oracle.connect("user/pw@tns")
cursor = connection.cursor()
cursor.arraysize = 5
cursor.execute("select someblob from sometable")
rows = cursor.fetchall()

where the number of rows returned is greater than 5, then yes, you are
correct. Unfortunately, that is the way that Oracle works. Internally a
LOB locator is what is actually fetched but it is only valid as long as
no additional fetches take place. The arraysize you specify defines the
number of rows that are fetched in each internal fetch. If you ask for
all of the rows, as many internal fetches will take place as needed and
so the original LOB locators will be overwritten. A couple of other
people have mentioned this problem to me as well so perhaps I ought to
add some code to check for this situation and at least raise an error,
eh? Any thoughts on that?

In the meantime, your problem will disappear completely if you use the
following method:

while 1:
    row = cursor.fetchone()
    if row is None:
        break
    do_some_stuff()

OR, if you are in Python 2.2 and running cx_Oracle 3.0 or greater

for row in cursor:
    do_some_stuff()

On Mon, 2003-07-07 at 08:07, Birgit Dreyer wrote:
> Hello,
> 
> if you select LOBs with an arraysize smaller than the resulted select
> lists, your LOB Locators points to the LOBs of the first array.
> 
> regards,
> 
> Birgit
> 
> 
> 
> 
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-- 
Anthony Tuininga
an...@co...
 
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