[xslt] libxslt performance problem

["Kaarle Kaila" <kaarle kaila fi>]

hi,

I have been using libxml and libxslt in my MFC (Microsoft VC++6)
genealogical applications to create reports from the database since 2004.

Only now I needed to create somewhat larger reports than before and I did
encounter performance problems. I have a database that contains around 25000
persons that go into 2900 families. There is quite a lot of textual
information for the persons too.

My application could not create the report in one go so I had to split the
report into 4 parts 1000 families in 3 parts and the indexes in part 4. To
create one such report from a memory based dom-tree takes 3 min 30 secs
using libxslt. My Java test-application could manage the whole report (of
2900 familes) but required additional heap space. Where do I specify the
heap space for libxslt.

I made a comparison using saxon 6.6.5 takes 25 s.

My xslt stylesheets have some libxslt specific (xslt 1.1) elements and do
not run on all xslt engines. I had heard that saxon would be close on it did
function in this case. Some of my xslt stylesheets works only with libxslt.
Seems I have misused some features like the document instruction etc.

I don't remember the version of my libxslt but I built it in the summer
2004. It wasn't so easy so I have not retried it.