Hub Central builds a TDE template for each entity for me, so why am I getting “SQL-TABLENOTFOUND — Unknown table”?
Author: Dave Cassel
SPARQL Update and locks
MarkLogic’s sem.sparqlUpdate normally runs as a separate transaction, which has implications for how locks are managed.
Peer reviewing a NiFi flow
We’re used to doing reviews for source code. NiFi flows look different, but when they are part of your application’s code, it’s useful to have a review prior to committing. Here’s what I look for when I’m reviewing a flow.
Making updates safe for parallel processing
Protect yourself from the Lost Update problem in MarkLogic.
Setting an attribute with a dynamic property name
The NiFi EvaluateJsonPath processor lets you specify a JSON path, which will be applied to the content of a flow file. For most situations that works great, but what if you want to retrieve a value where the property you want to read depends on a flow file attribute? EvaluateJsonPath doesn’t support the expression language on dynamic attributes. Use an ExecuteScript processor instead.
Why hire us?
How can 4V Services help you achieve your goals?
Comparing xs.dateTime values
When working with MarkLogic’s xs.dateTime values, always use the provided operators. Read on to see why.
Processing upstream deletes
We can load data into a data hub from a variety of upstream data sources. What if we want to delete documents that have been deleted upstream? In the ideal case we’re using a Change Data Capture system and we get notifications about those deletions, but sometimes we don’t have that. How can we detect what’s been deleted if we don’t get notified?
Working with JSON in XQuery
Searching for one result
MarkLogic is both a database and a search engine. Sometimes, you know you only want one result from your search. What’s a good way to do that?