After I've run the algorithm (Dijkstra Single Source), the outcome is following:
match (source:Node1 {NAME:'H'})
call gds.allShortestPaths.dijkstra.stream('undirectedGOES', {sourceNode: source})
yield index, sourceNode, targetNode, nodeIds, path
return
index, sourceNode, targetNode, nodeIds, path
order by index
I know I can use nodes(path) function to show only one path, but that function only returns the original paths (which have incorrect directions).
match (source:Node1 {NAME:'H'})
call gds.allShortestPaths.dijkstra.stream('undirectedGOES', {sourceNode: source})
yield index, sourceNode, targetNode, nodeIds, path
return
index, sourceNode, targetNode, nodeIds, nodes(path) as path
order by index
Is there a way to show only a single path between nodes, but produced by the algorithm?
Some directions are different (before and after running the algorithm) and that piece of information is exactly what I need.
Related
I used the following request
http://localhost:8983/solr/test6/select?q=*:*&sort=product(score,hits)%20desc
to sort results based on their relevancy score as determined by Apache Solr multiplied by a field called hits (integers).
However, I receive the following error message:
{ "responseHeader":{
"status":400,
"QTime":0,
"params":{
"q":"*:*",
"sort":"product(score,hits) desc"}}, "error":{
"metadata":[
"error-class","org.apache.solr.common.SolrException",
"root-error-class","org.apache.solr.common.SolrException"],
"msg":"sort param could not be parsed as a query, and is not a field that exists in the index: product(score,hits)",
"code":400}}
Why is it that sort cannot correctly input the function value when:
http://localhost:8983/solr/test6/select?q=*:*&sort=score%20desc
http://localhost:8983/solr/test6/select?q=*:*&sort=hits%20desc
work when a function isn't applied?
NOTE: http://localhost:8983/solr/test6/select?q=*:*&sort=product(hits,2)%20desc where I added the product() function also returns the same error message.
The score value isn't really a field - so you can't use a function to manipulate it in the sort clause.
Instead you can use a multiplicative boost through boost (if you're using edismax) to achieve what you want: &boost=hits. You might want to use log(hits) or something similar (recip for example) instead to avoid large differences in score for just small changes in the number of hits.
I'm prototyping a simple "output" filter with Apache + mod_lua. How can I read response body, at the end of other native output filters applied, via LUA? For example, can I get the actual response that will be sent to the client?
The manual has some good guidance on this:
http://httpd.apache.org/docs/current/mod/mod_lua.html#modifying_buckets
Modifying contents with Lua filters Filter functions implemented via
LuaInputFilter or LuaOutputFilter are designed as three-stage
non-blocking functions using coroutines to suspend and resume a
function as buckets are sent down the filter chain. The core structure
of such a function is:
function filter(r)
-- Our first yield is to signal that we are ready to receive buckets.
-- Before this yield, we can set up our environment, check for conditions,
-- and, if we deem it necessary, decline filtering a request alltogether:
if something_bad then
return -- This would skip this filter.
end
-- Regardless of whether we have data to prepend, a yield MUST be called here.
-- Note that only output filters can prepend data. Input filters must use the
-- final stage to append data to the content.
coroutine.yield([optional header to be prepended to the content])
-- After we have yielded, buckets will be sent to us, one by one, and we can
-- do whatever we want with them and then pass on the result.
-- Buckets are stored in the global variable 'bucket', so we create a loop
-- that checks if 'bucket' is not nil:
while bucket ~= nil do
local output = mangle(bucket) -- Do some stuff to the content
coroutine.yield(output) -- Return our new content to the filter chain
end
-- Once the buckets are gone, 'bucket' is set to nil, which will exit the
-- loop and land us here. Anything extra we want to append to the content
-- can be done by doing a final yield here. Both input and output filters
-- can append data to the content in this phase.
coroutine.yield([optional footer to be appended to the content])
end
Started using Cypher about a week ago (really like it). In the 'browser' interface I'm running two queries:
1) start n=node:Node(name="foo") match (n)-[r*..4]-(m) return n,m
2) match (n{name:"foo"})-[r*..4]-(m) return n,m
The first query returns almost immediately, the second query more than an hour and counting. Naively I would think these would be equivalent, clearly they are not. I ran a 'smaller' (path just up to 1) version of both in the neo-shell so I could profile them.
profile start n=node:Node(name="foo") match (n)-[r*..1]-(m) return n,m;
ColumnFilter(symKeys=["m", "n", " UNNAMED51", "r"], returnItemNames=["n", "m"], _rows=4, _db_hits=0)
TraversalMatcher(start={"expr": "Literal(foo)", "identifiers": ["n"], "key": "Literal(name)",
"idxName": "Node", "producer": "NodeByIndex"}, trail="(n)-[*1..1]-(m)", _rows=4, _db_hits=5)
.
profile match (n{name:"foo"})-[r*..1]-(m) return n,m
ColumnFilter(symKeys=["n", "m", " UNNAMED33", "r"], returnItemNames=["n", "m"], _rows=4, _db_hits=0)
Filter(pred="Property(n,name(0)) == Literal(foo)", _rows=4, _db_hits=196870)
TraversalMatcher(start={"producer": "AllNodes", "identifiers": ["m"]},
trail="(m)-[*1..1]-(n)", _rows=196870, _db_hits=396980)
From other stackoverflow questions I understand db_hits is good to look at, so it looks like the second query has basically done a linear scan (my db is almost 400k nodes). This seems to be confirmed by the "producer" value of "AllNodes" instead of "NodeByIndex".
Obviously I need to specify the match (predicate) differently so that it hits the index. The index is called 'Node' on parameter 'name'. My googling, stacko search is failing me.. how do I specify the conditional in the match so that it hits the index?
Update:
After some poking around it appears I'm using a 'legacy' index? and then trying to hit that with the 'new style (don't use start) query... (kinda extrapolating here). So I can do the following:
create index ON :label(name)
and that would provide an index for a particular label on the name property, but I really want an index (I guess non-legacy index) on ALL the node names. I have use cases where that's important (user may not know the label but does know the name).
Any suggestions or guidance is much appreciated.
Right now there is no global schema index, so you would probably want to create an index on a generic label like Entity or Node and create an index like this:
create index on :Entity(name);
And add that Entity label to all your nodes.
match (n) set n:Entity;
I was very surprised that I couldn't find this answer on Google.
I have seen someone access the default Apache index page (no index.html present, so it just shows the directory listing) with query string parameters. The URL they used was similar to:
http://example.com/?C=M;O=D
It looks like O=D means "order = descending," since it reversed the order of the list, but I want to know what other parameters can be passed in, and what they mean. Is this documented somewhere? I couldn't find it.
From http://www.gforums.net
"C=M;O=D" is the query string passed in to the URLs that are browseable. It's used to sort the files list.
O is the sort order, which can either be A or D for ascending and descending respectively.
C is for column name which is to be sorted. It can take the following values:
N - Name (file name) column
M - Last Modified column
S - Size column
D - might be for Description
You might want to have a look at this : https://httpd.apache.org/docs/2.2/mod/mod_autoindex.html
I'm creating some tests with JMeter, the situation is very simple, I have a search page with a list of results, and I have to retrieve from this results some values to use in the next request.
Those results are around 350, I don't need them all.
I used the RegexExtractor to retrieve those results and it works (I setted it to retrieve just 10 results), but now I don't know how to access the results inside a LoopCounter.
The extractor put the results into a variable named Result.
The problem is that I don't know hot to build dinamically the name of a variable.
Do I have to use some function like _p()??
I can access the variable just putting the static name Result_0_g1
Inside the LoopCounter I putted also a Counter to store the loop count into the variable index
Thank you
EDIT:
SOLVED I have to write:
${__V(Result_${index}_g1)
You have to reference the variable with the function:
${__V(Result_${index}_g1)
...Just for collection.
See also this post for another implementation (case without using ForEach Controller):
ThreadGroup
HttpSampler
Regex Extractor (variableName = links)
WhileController(${__javaScript(${C} < ${links_matchNr})})
HTTPSampler use ${__V(links_${C})} to access the current result
Counter (start=1, increment=1, maximum=${links_matchNr}, referenceName=C)
Use the ForEach Controller - it's specifically designed for this purpose and does exactly what you want.
You may use ForEach Controller:
ThreadGroup
YourSampler
Regular Expression Extractor (match -1, any template)
Foreach controller
Counter(Maximum -> ${Result_matchNr} , Rf Name -> index)
LinkSamplerUsingParsedData(use -> ${__V(Result_${index}_g1)}
Now, if you want to iterate to all groups, you need another foreach to do that. As you know which group represent what value, you can use this way.