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Data item expressions from a library [message #482233]

Tue, 25 August 2009 15:05

Eclipse User

We're trying to use a library to define a Data element which we use across
multiple reports. The element's expression is a non-trivial formula.

Functionally, this is working, however this approach is killing
performance (in 2.3.2.1 at least). We're seeing report generation time go
from 12s to 5 minutes, and the rptdocument go from 18MB to 146MB, although
the outputs seem to match.

I know there are some caching enhancements in 2.5, but we're stuck w/ 2.3
for now, so I'd love to hear ideas for a work-around, if any exist other
than copy/pasting our expression into local Data elements on each report.

I can also reproduce this w/o a library. Essentially the acceptable
performance occurs when the Data element references a binding on the
table, and the poor performance occurs when the Data element has its own
bindings (which is how it would come from a library).

Thanks,

James

Re: Data item expressions from a library [message #482234 is a reply to message #482233]

Tue, 25 August 2009 15:07

Eclipse User

Clarification of first paragraph - I'm comparing the same report, except
that one uses a library-defined Data element while on the other I've
manually added the Data element and set it's expression.

Re: Data item expressions from a library [message #482424 is a reply to message #482234]

Wed, 26 August 2009 09:48

Eclipse User

James,

Have you tried using a text element with the value-of expression in a
library? It would be good if you could reproduce the problem using the
sample db so we can see what is causing the issue.

Jason

James Koch wrote:
> Clarification of first paragraph - I'm comparing the same report, except
> that one uses a library-defined Data element while on the other I've
> manually added the Data element and set it's expression.
>

Re: Data item expressions from a library [message #482454 is a reply to message #482424]

Wed, 26 August 2009 11:34

Eclipse User

We'll give the text element a try.

To reproduce w/ the sample DB, here are two rptdesign files:

http://jameskoch.googlepages.com/GroupingLabelPerf-Library.r ptdesign

http://jameskoch.googlepages.com/GroupingLabelPerf-Local.rpt design

The "local" one just has the data item added the way the designer does it
(a new table binding is created, and referenced by the data item).

The "library" one is how it appears when we drag a library-defined data
element over (it has its own bindings).

There's no noticeable performance issue here but the size difference in
the rptdocument is observable - "local" is 2,375K and "library" is 4,498
for the same output. I suspect multiple round-trips to the data source
are happening under "library", causing a dramatic slow down in cases like
ours where a beefier PROC is running each time.

Re: Data item expressions from a library [message #482518 is a reply to message #482454]

Wed, 26 August 2009 17:14

Eclipse User

James,

Can you post the library you used?
BTW I did not see a reference to a library in the example report.

Jason

James Koch wrote:
> We'll give the text element a try.
>
> To reproduce w/ the sample DB, here are two rptdesign files:
>
> http://jameskoch.googlepages.com/GroupingLabelPerf-Library.r ptdesign
>
> http://jameskoch.googlepages.com/GroupingLabelPerf-Local.rpt design
>
> The "local" one just has the data item added the way the designer does
> it (a new table binding is created, and referenced by the data item).
>
> The "library" one is how it appears when we drag a library-defined data
> element over (it has its own bindings).
>
> There's no noticeable performance issue here but the size difference in
> the rptdocument is observable - "local" is 2,375K and "library" is 4,498
> for the same output. I suspect multiple round-trips to the data source
> are happening under "library", causing a dramatic slow down in cases
> like ours where a beefier PROC is running each time.
>

Re: Data item expressions from a library [message #482691 is a reply to message #482518]

Thu, 27 August 2009 10:41

Eclipse User

Jason,

In the http://jameskoch.googlepages.com/Gro...rary.rptdesign, James has
mimicked the binding of the data element "From Library" just like as if it
was added from the library.

Hope this helps.

Re: Data item expressions from a library [message #482720 is a reply to message #482691]

Thu, 27 August 2009 12:49

Eclipse User

Ok now I understand. The group data element contains a data binding
which is nested in the table binding, which is most likely why it is
growing. It is probably parsing the data set twice because of the
nested binding. I changed your report to use a text element and the
size went back to the original size.

Jason

SuperTime wrote:
> Jason,
>
> In the http://jameskoch.googlepages.com/Gro...rary.rptdesign, James has
> mimicked the binding of the data element "From Library" just like as if
> it was added from the library.
>
> Hope this helps.
>
>

Chart and Table aligned [message #482891 is a reply to message #482454]

Fri, 28 August 2009 09:19

Eclipse User

Hello,

Is it possible to have a chart (let's say a bar-chart) and just below of
it a table with the values.

I can do that manually, but is not a clean (not to mention elegant) way: I
have to play with the sizes (chart/table) until it somehow fits: the
borders of the columns of the table (nearly) match the X-Axis gridlines.

I would be also happy with a better workaround if not a straight-fwd
solution :)

Thanks!
Tero

Re: Chart and Table aligned [message #482932 is a reply to message #482891]

Fri, 28 August 2009 11:10

Eclipse User

Tero,

Can you post an example? In 2.5 you can set label spans in the chart to
help align two charts. This may help with your situation.

Jason

Tero wrote:
> Hello,
>
> Is it possible to have a chart (let's say a bar-chart) and just below of
> it a table with the values.
> I can do that manually, but is not a clean (not to mention elegant) way:
> I have to play with the sizes (chart/table) until it somehow fits: the
> borders of the columns of the table (nearly) match the X-Axis gridlines.
>
> I would be also happy with a better workaround if not a straight-fwd
> solution :)
>
> Thanks!
> Tero
>

Re: Data item expressions from a library [message #485426 is a reply to message #482720]

Fri, 11 September 2009 13:16

Eclipse User

Wow, a thread-jacking!

I've made an interesting related finding here. Even w/ non-library data items in our header (IOW, there's no duplicate data-item-level binding, which was our original issue), we get a 45% performance boost when we switch to text elements.

Some facts & wild theories:
- We have a 10-20 line expression needed for our header/footer labels.
- When you add them as a DataItem you get an associated Table Binding.
- I'm guessing that this means the expression is evaluated on every row, rather than just on the change of groups.
- We have a large # of rows, so there's a huge cost to compute the expression w/ every row, so switching to a text element gives us a giant boost by (presumably) evaluating only on change of group.

[Updated on: Fri, 11 September 2009 13:17] by Moderator

Re: Data item expressions from a library [message #485431 is a reply to message #485426]

Fri, 11 September 2009 13:30

Eclipse User

James,

Is this page or table headers?

Jason

James Koch wrote:
> Wow, a thread-jacking!
>
> I've made an interesting related finding here. Even w/ non-library data
> items in our header (IOW, there's no duplicate data-item-level binding,
> which was our original issue), we get a 45% performance boost when we
> switch to text elements.
>
> Some facts & wild theories:
> - We have a 10-20 line expression needed for our header/footer labels.
> - When you add them as a DataItem you get an associated Table Binding.
> - I'm guessing that this means the expression is evaluated on every row,
> rather than just on the change of groups. - We have a large # of rows,
> so there's a huge cost to compute the expression w/ every row, so
> switching to a text element gives us a giant boost.

Re: Data item expressions from a library [message #485959 is a reply to message #485431]

Tue, 15 September 2009 13:05

Eclipse User

Table headers. 2.3.2.1.

Re: Data item expressions from a library [message #485983 is a reply to message #485959]

Tue, 15 September 2009 15:19

Eclipse User

James,

Any chance you could open a bug with these results?

Jason

James Koch wrote:
> Table headers. 2.3.2.1.
>

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