I ran into a peculiar issue with importing an XML file from DrugBank into BaseX. It involves the file header, which looks like this:
<?xml version="1.0" encoding="UTF-8"?>
<drugbank xmlns="http://www.drugbank.ca" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.drugbank.ca http://www.drugbank.ca/docs/drugbank.xsd" version="5.0" exported-on="2017-08-31">
The XML file (which is quite large ~3GB) loads in cleanly but queries executed against it produce no output (no errors reported).
When I change the header to the following and re-import the file everything works fine:
<?xml version="1.0" encoding="UTF-8"?>
<drugbank>
I had this issue for a while (go thought this every month) so thought it might be good to share. I am currently using BaseX 8.6.4.
Any idea why this is happening? Attached is the console trace for both cases (they show subtle differences in the query plans).