CQEngine – Collection Query Engine – is a NoSQL indexing and query engine, for retrieving objects matching SQL-like queries from Java collections
CQEngine – Collection Query Engine – Ultra-fast SQL-like queries on Java collections.
Questions tagged [cqengine]
27 questions
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Java cqengine group by and sum like SQL
I'm investigating the use of cqengine as the cost of re querying the database would be too costly, but I'm really struggling to retrieve the data I need.
IndexedCollection rows =…
Nick
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CQengine incompatibility with JSONArray : java.lang.IllegalStateException thrown for JSONArray in AttributeBytecodeGenerator.java
When the member object passed on to the getGenericType() method in AttributeSourceGenerator.java corresponds to 'public org.json.JSONArray', then the following exception is thrown :-
java.lang.IllegalStateException: Failed to create attribute for…
Akhil Ranjan
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CQEngine Query nested object using parser.retrieve
I have a nested object like
public class SQSMessage implements Serializable {
private String type;
private boolean isEntity;
private String eventType;
private SystemInfo systemInfo;
private DomainAttributes domainAttributes;
…
0
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1 answer
CQEngine query overhead / precompiled parameterized queries
When I query an indexed collection many times and the query is the same and only differs in the attribute value, how big is the overhead to execute it?
Is there a way to precompile a parameterized query to get rid of this overhead?
Edit: Here's a…
Inego
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Query for one or more list of values to get objects with a field that is a list of values CQEngine
I am using QueryCache (CQEngine) to store a list of Alarms in memory. The alarm object has a ID, and Zones fields. The indexed field is ID, and the zones is list of strings with the name of the zone where the alarm occurred. I am trying to compare…
Rasheed
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Add message store spring integration dsl
I am currently looking at the options to add real-time tracking of all the messages going over in my application.
I have enabled messagehistory so technically I'll get all the steps happened during the flow.
Now I want to store each message with the…
Makky
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Getting exception "attempted duplicate class definition" while creating attribute through AttributeByteCodeGenerator
When implementing cqengine in our application, getting exception "javassist.CannotCompileException: by java.lang.ClassFormatError: loader (instance of sun/misc/Launcher$AppClassLoader): attempted duplicate class definition" from method…
Diksha gupta
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Indexing a simple Java Record
I have a Java Object, Record . It represents a single record as a result of SQL execution. Can CQEngine index collection of Record ?
My class is of the form
public class Record {
private List columnNames;
private List
suraj1291993
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cqengine IndexedCollection add causing nullpointer
I'm currently getting this error when I add elements to an IndexedCollection:
HIGHEST: null
java.lang.NullPointerException
at java.util.concurrent.ConcurrentSkipListMap.doGet(ConcurrentSkipListMap.java:778)
at…
Hooli
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Oracle distinct vs java (cqengine/set) : whose leads to better performances?
I have a table from which I extract 8 columns, said columns will be properties of a pojo, say MyPojo.
I want to remove duplicates.
I came up with two strategies.
1-Let oracle take care of this with distinct keyword
select distinct c1,c2...c8 from…
Phate
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2 answers
How to Unpack/ Simplify Anonymous Inner Class
The goal of this post is to find out how to avoid using anonymous inner classes.
I have not worked extensively with inner anonymous classes but I am trying to simplify the following lines of code in someone's package…
Arthur W
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1 answer
Does CQEngine support transactional update?
I wish to have a queryable on-heap mirror of some underlying resource. When using CQEngine to index a class not under our control (*), how can we implement a transactional update (what's the point of all this concurrency if readers lose data because…
drekbour
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