Hi Dave,
Like you, because of my RDBMS background, I had to feel the ‘document’ paradigm in order to obtain good performance results.
I suggest you do not try to update your catalog document in place using XQuery Update facility.
A simple solution is to add each daily-update, and annotate it with a my-sort-value value you can sort on (the date in your use case).
When looking for a given SKU, use an index to obtain the list of entry elements, ordered by descending my-sort-value, and take the first item.
When you hit performance or storage limits, create a collection containing only the latest version of each entry element.
But as your data is not really document oriented, did you consider using JSON repositories like couchbase ?
You could choose to store each entry element in a separate document with SKU as key.
Coupled with just a little preprocessing step - that could be written easly in XQuery - transforming your entries element in a JSON array of entry objects,
you will obtain incredible performance.
Couchbase as a ‘SQL like’ language to query your bucket of documents called N1QL.
Best regards,
Fabrice
De : BaseX-Talk [mailto:basex-talk-bounces@mailman.uni-konstanz.de]
De la part de Dave Kopecek
Envoyé : dimanche 14 octobre 2018 00:10
À : basex-talk@mailman.uni-konstanz.de
Objet : Re: [basex-talk] Database Updates
Here are some tweaked examples & better problem definition:
Given a database created from catalog.xml below, what's the best way to update & add records received daily as in file daily-update.xml?
For every <ENTRY> node in daily-update.xml
-- If ENTRY/SKU found in catalog.xml replace the entire <ENTRY> node in catalog.xml with the one from daily-update.xml
-- If ENTRY/SKU not found in catalog.xml add the <ENTRY> node from daily-update.xml to catalog.xml
catalog.xml
<?xml version="1.0" encoding="UTF-8"?>
<CATALOG>
<ENTRIES>
<ENTRY>
<SKU>1</SKU>
<TITLE>Empire Burlesque</TITLE>
<ARTIST>Dylan</ARTIST>
<PRICE>10.90</PRICE>
</ENTRY>
<ENTRY>
<SKU>2</SKU>
<TITLE>Hide your heart</TITLE>
<ARTIST>Bonnie Tyler</ARTIST>
<PRICE>9.90</PRICE>
</ENTRY>
</ENTRIES>
</CATALOG>
daily-update.xml
<?xml version="1.0" encoding="UTF-8"?>
<CATALOG>
<ENTRIES>
<ENTRY>
<SKU>1</SKU>
<TITLE>Empire Burlesque</TITLE>
<ARTIST>Bob Dylan</ARTIST>
<PRICE>29.99</PRICE>
<NEWTHING>some value</NEWTHING>
</ENTRY>
<ENTRY>
<SKU>5</SKU>
<TITLE>Tupelo Honey</TITLE>
<ARTIST>Van Morrison</ARTIST>
<PRICE>8.20</PRICE>
</ENTRY>
</ENTRIES>
</CATALOG>
catalog.xml after daily update:
<CATALOG>
<ENTRIES>
<ENTRY>
<SKU>1</SKU>
<TITLE>Empire Burlesque</TITLE>
<ARTIST>Bob Dylan</ARTIST>
<PRICE>29.99</PRICE>
<NEWTHING>some value</NEWTHING>
</ENTRY>
<ENTRY>
<SKU>2</SKU>
<TITLE>Hide your heart</TITLE>
<ARTIST>Bonnie Tyler</ARTIST>
<PRICE>9.90</PRICE>
</ENTRY>
<ENTRY>
<SKU>5</SKU>
<TITLE>Tupelo Honey</TITLE>
<ARTIST>Van Morrison</ARTIST>
<PRICE>8.20</PRICE>
</ENTRY>
</ENTRIES>
</CATALOG>
Thanks,
-Dave
On Fri, Aug 17, 2018 at 11:27 AM Dave Kopecek <dave.kopecek@gmail.com> wrote: