[Zope] Z-SQL Method performance

[Jens Vagelpohl]

in a nutshell, the external method will be faster because you can use it to 
circumvent security checking.

when a large result from a ZSQL method is coming back to a page that 
renders it then zope will do a security check on every single item (not 
just every line) of that record to determine if the current user is allowed 
to see this item. so if your result set has 10,000 rows and 5 columns in 
each row then the security machinery will check 50,000 times.

one exception where the security machinery will not check are simply python 
types (the return values from a ZSQL method are objects that contain the 
results and not simple types), such as strings, lists, dictionaries etc. so 
if you use an external method to get the result set and then convert it 
inside the external method to such a simple type and hand that back to DTML 
you will see a marked increase in speed.

jens


On Thursday, April 4, 2002, at 04:08 , Luca Manini wrote:

>> It's almost surely not the Z SQL Method but the DTML rendering
>> that makes it slow.
>
>> Use an External Method to generate the HTML from the query
>> result.
>
>> Dieter
>
>     Just out of curiosity:
>
>     1 - (technical)  why would the external method by faster?
>     2 - (meta)       rendering HTML is "the" DTML job, isn't it?
>
> 	bye, Luca.
>