[reportlab-users] Large tables are very slow to produce

[Mark Matthews]

On 09/11/2007, at 12:27 PM, Andy Robinson wrote:


> Try making 5000 1-row tables and see how much faster it gets.  That

> will tell us if it's a problem with recursively sizing the whole

> things, and under the hood it's just as good a solution.

>

> Or, if your data breaks into more sensible sized bands with some kind

> of group sub-totals, make each band a table of its own.  If a table

> usually fits on one page, you'll get good performance.  This also

> makes formatting easier too as you don't need to do clever

> computations on which rows to apply different styles to.

>

> The problem is that we may be trying to auto-size the whole thing

> (longTable is supposed to fix this), or perhaps eating a lot of

> memory.  If you are explicitly setting the column widths yourself,

> which makes for tidier documents and makes things faster anyway,

> there's no reason to have one huge table.

>

> Hope this helps,


Thanks for the immediate response;

As an aside (I had read this: http://two.pairlist.net/pipermail/reportlab-users/2004-May/003027.html 
  and wondered if this was recommended)

1)  a 1000 line table, with repeating rows takes: ~1m5s
2) If I split this into 100 10 line table it takes 8s


-------------------------------------------------
Mark Matthews
General Manager
Object Craft Pty Ltd
Phone: +61 3 9654 9099
http://www.object-craft.com.au