Is it possible to create an index on the nodes/relationships of a graph in AGE? If so, what is the syntax?
I was unable to find anything about it in the documentation.
There is an issue currently open related to this:
https://github.com/apache/age/issues/45
At this moment seems there no complete support for this. There is an Open PR for OpenCypher as well:
https://github.com/opencypher/openCypher/pull/166
If however you are okay with Neo4j you can look into it.
For more information regarding implementation in Cypher queries: https://github.com/Mats-SX/openCypher/blob/c542f94f07fb934254748f4f2ce44612d45866a3/cip/vendor-extensions/neo4j/CIP2016-12-14-Neo4j-indexes.adoc
Related
I am using ckan 2.6.0
According with the documentation: http://docs.ckan.org/en/latest/api/legacy-api.html
I am trying to use the endpoint /rest/dataset and works (only for public data but works), it only returns an array of datasets names, and nothing else, an example can be found here http://demo.ckan.org/api/1/rest/dataset
Is there a way to get a complete listing for datasets ? I also tried the search endpoint and returns the same array.
For example I would like to get the title, description, tags, file types, etc, like in the image below:
The REST api is deprecated/unmaintained and has been for a long time. Follow the up-to-date API documentation here.
package_search is your best bet: http://demo.ckan.org/api/action/package_search
That gives you a batch of datasets. Get more by paging through using the 'start' and 'rows' parameters.
If you simply want them all, then it's much better still to use a bulk download that some sites offer, such as data.gov.uk, which supplies it complete as a simple JSONL download: Meta-data for data.gov.uk datasets.
I don't expect to get an answer on this but if anyone can help it would be greatly appreciated.
We're using HP Application Lifecycle Management 12.2 (ALM or QC/QualityCenter as it's called). I'm trying to retrieve test resources from the project using the REST api but I suspect I've come across a defect in the API.
I'm trying to filter the response by using a query, and any other query works fine but when I try to use the 'folder-name' field it fails with the following message:
Failed to set params in the parametrized query
It doesn't matter what format I try to escape the query with, I've tried the following:
/resources/?query={folder-name[%27folder%27]}
/resources/?query={folder-name['folder']}
/resources/?query=%7bfolder-name%5b%27folder%27%5d%7d
I've also reproduced this on an 11.52 QC instance so it's not just our environment. I've double checked the customization collection using the ?can-filter=true param and folder-name is supposed to be filterable.
I'm currently using the parent-id for filtering instead which works but it requires me to do another request to get the parent-id first which I would like to refrain from.
Any suggestions, patches?
Thanks
As I wrote in the comments, the error is reproducable here, and I agree that it is strange. The folder-name exists as a field in resource, and should be filterable. It seems to be a bug.
But there is another approach that I offer as a substitute solution. The resource entity offer a relation directly to the folder entity, and you can get the exact result you were looking for, by using a cross join with that table:
/resources/?query={resource-folder.name['folder']}
This is probably too late to help you with your work, but it might help others.
We need to restrict a MarkLogic search to the latest version of managed documents, using Marklogic's REST api. We're using MarkLogic 6.
Using straight xquery, you can use dls:documents-query() as an additional-query option (see
Is there any way to restrict marklogic search on specific version of the document).
But the REST api requires XML, not arbitrary xquery. You can turn ordinary cts queries into XML easily enough (execute <some-element>{cts:word-query("hello world")}</some-element> in QConsole).
If I try that with dls:documents-query() I get this:
<cts:properties-query xmlns:cts="http://marklogic.com/cts">
<cts:registered-query>
<cts:id>17524193535823153377</cts:id>
</cts:registered-query>
</cts:properties-query>
Apart from being less than totally transparent... how safe is that number? We'll need to put it in our query options, so it's not something we can regenerate every time we need it. I've looked on two different installations here and the the number's the same, but is it guaranteed to be the same, and will it ever change? On, for example, a MarkLogic upgrade?
Also, assuming the number is safe, will the registered-query always be there? The documentation says that registered queries may be cleared by the system at various times, but it's talking about user-defined registered queries, and I'm not sure how much of that applies to internal queries.
Is this even the right approach? If we can't do this we can always set up collections and restrict the search that way, but we'd rather use dls:documents-query if possible.
The number is a registered query id, and is deterministic. That is, it will be the same every time the query is registered. That behavior has been invariant across a couple of major releases, but is not guaranteed. And as you already know, the server can unregister a query at any time. If that happens, any query using that id will throw an XDMP-UNREGISTERED error. So it's best to regenerate the query when you need it, perhaps by calling dls:documents-query again. It's safest to do this in the same request as the subsequent search.
So I'd suggest extending the REST API with your own version of the search endpoint. Your new endpoint could add dls:documents-query to the input query. That way the registered query would be generated in the same request with the subsequent search. For ML6, http://docs.marklogic.com/6.0/guide/rest-dev/extensions explains how to do this.
The call to dls:documents-query() makes sure the query is actually registered (on the fly if necessary), but that won't work from REST api. You could extend the REST api with a custom extension as suggested by Mike, but you could also use the following:
cts:properties-query(
cts:and-not-query(
cts:element-value-query(
xs:QName("dls:latest"),
"true",
(),
0
),
cts:element-query(
xs:QName("dls:version-id"),
cts:and-query(())
)
)
)
That is the query that is registered by dls:documents-query(). Might not be future proof though, so check at each upgrade. You can find the definition of the function in /Modules/MarkLogic/dls.xqy
HTH!
I'm using the Neography gem to interact with a Neo4j database through the REST API. I don't see any way in Neography itself (though if it's there, I'd love to use it!), nor have I been able to find by searching on Google whether this is possible directly through the REST API itself. Does anyone out there with Neo4j experience happen to know?
With Neography, you can send this Gremlin script:
#neo = Neography::Rest.new
#neo.execute_script("g.clear()")
to remove all the nodes and relationships.
To clear all nodes and relationships except the root node, use the solution provided in neography wiki
#neo = Neography::Rest.new
#neo.execute_query("START n0=node(0),nx=node(*) MATCH n0-[r0?]-(),nx-[rx?]-() WHERE nx <> n0 DELETE r0,rx,nx")
I am new to Cassandra and I am having some difficulties fetching data.
I looked into the function:
list<KeySlice> get_range_slices(column_parent, predicate, range, consistency_level)
But, I do not understand what the column_parent is supposed to be.
Anybody any idea?=
Thanx,
Granit
column_parent is basicly used for indicator of ColumnFamily(but in rare cases it can indicate a supercolumn). In java you would put : new ColumnParent("Posts") there. but there should be one more parameter for namespace in get_range_slices query, I guess you are not using thrift but a client api. then you should check your client's documentation.
Edit:
the definition of ColumnParent in cassandra api :
The ColumnParent is the path to the
parent of a particular set of Columns.
It is used when selecting groups of
columns from the same ColumnFamily. In
directory structure terms, imagine
ColumnParent as ColumnPath + '/../'.
Frail is correct, but the real answer is "don't use raw Thrift, use one of the clients from http://wiki.apache.org/cassandra/ClientOptions instead."