The advantage of SXSSF over HSSF and XSSF is that the spreadsheet is built
to disk, rather than java memory. It sounds counter intuitive, but the
stream to disk is faster. I believe that the time savings increases
exponentially with the spreadsheet memory footprint. I said previously,
that I saw similar sized spreadsheet >10,000 rows generate in half the time
with SXSSF. Why would your user base squawk at improved generation times?
I've also generated >1 million records in around half an hour. This was
something that crashed XSSF perviously due to memory constraints.
To fully take advantage of the memory savings, you need to make sure you're
using the SS_begin_object_group(100) and ss_end_object_group() in your
code.
To use SXSSF, you'll of course, need the latest POI java .jar files.
You'll also need to add the following two methods to your HSSF_H include
source file, assuming that you're using Scott Klement's stuff: By the way,
this doesn't require a recompile on the HSSF service program itself, this
only affects the source include.
D SXSSF_Workbook_Class...
D C 'org.apache.poi.xssf.streaming-
D .SXSSFWorkbook'
D SXSSFWorkbook S O CLASS(*JAVA:
SXSSF_WORKBOOK_CLASS)
D SXSSF_Workbook_Class...
D C 'org.apache.poi.xssf.streaming-
D .SXSSFWorkbook'
D SXSSFWorkbook S O CLASS(*JAVA:
SXSSF_WORKBOOK_CLASS)
*-----------------------------------------------------------------
* SXSSF_dispose(): Delete temporary file when done with save
*------------------------------------------------------------------
D SXSSF_dispose PR n
D EXTPROC(*JAVA
D : SXSSF_Workbook_Class
D :'dispose')
From: "John Allen" <jallen@xxxxxxxxxxx>
To: "'RPG programming on the IBM i \(AS/400 and iSeries\)'"
<rpg400-l@xxxxxxxxxxxx>
Date: 12/19/2014 12:05 PM
Subject: RE: New SXSSF spreadsheet generation
Sent by: "RPG400-L" <rpg400-l-bounces@xxxxxxxxxxxx>
I see a lot of references to using POI and SXSSF to create
XLSX files.
But they almost all refer to speed in generic terms "Slow",
"Faster", "twice as fast"
Can you or anyone else give me an idea what Faster or Slow
means in terms of x minutes to create Y rows with Z columns
I know that it depends on the number of columns and rows and
formatting and system etc. etc.
I am looking for some better defined (but still a little
generic) performance numbers
How long would it take to create an average spreadsheet
(5-10 columns with 10,000 rows)
Is this 3 minutes (which is slow to some people and fast to
others) or 15 minutes or whatever
We are already creating some rather large XLS files and
would like to switch to XLSX but I can't if the users that
are used to getting the XLS file in less than a minute will
have to wait 5 or 10 minutes.
I really don't want to take all the time to download
everything and program a test just to find out the speed is
unacceptable.
If I have at least some general performance numbers I know
if I should take the time for writing my own test on our own
data.
If several of you guys that are using SXSSF could give me
times that you are experiencing and what size spreadsheet
I can make a good WAG to see if I would be completely
wasting my time or if I should move forward with my own
test.
Thanks in advance
John
-----Original Message-----
From: darren@xxxxxxxxx [mailto:darren@xxxxxxxxx]
Sent: Wednesday, November 26, 2014 10:37 AM
To: midrange-RPG RPG message board
Subject: New SXSSF spreadsheet generation
We installed the newest Apache POI 3.10.1 API's for
generating spreadsheets that are called from Scott Klements'
service program series. The upgrade from 3.6 was pretty
painless, and I've found a great new feature in the
"Buffered Streaming" SXSSF workbook generations. I'm
finding I'm able to generate huge spreadsheets with
virtually no growth in heap memory, which means we can
generate even bigger spreadsheets without java dumps, and
the actual generation is about twice as fast.
http://poi.apache.org/spreadsheet/index.html
--
This is the RPG programming on the IBM i (AS/400 and
iSeries) (RPG400-L) mailing list To post a message email:
RPG400-L@xxxxxxxxxxxx To subscribe, unsubscribe, or change
list options,
visit:
http://lists.midrange.com/mailman/listinfo/rpg400-l
or email: RPG400-L-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at
http://archive.midrange.com/rpg400-l.
-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 2014.0.4765 / Virus Database: 4189/8633 - Release
Date: 11/26/14
--
This is the RPG programming on the IBM i (AS/400 and iSeries) (RPG400-L)
mailing list
To post a message email: RPG400-L@xxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit:
http://lists.midrange.com/mailman/listinfo/rpg400-l
or email: RPG400-L-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at
http://archive.midrange.com/rpg400-l.
midrange.com
