![]() ![]() These xml files are under the src/config folder of the Eclipse project which has already been created.Īnd also you should change the classpath parameters because in the pof-config.xml file there is a class that should be specified in the classpath to use pof configuration. =/home/oracle/labs/Coh_labs/workspace/CohExam_AFSungur/src/config/coherence-cache-config.xml =/home/oracle/labs/Coh_labs/workspace/CohExam_AFSungur/src/config/pof-config.xml To force coherence to read our cache configuration file we should edit the JAVA_OPTS parameter in the coherence_join_cluster_test1.sh file ( it was created in previous post ) and add this clause by changing the real path : ![]() To use existing cache ( this is the cache it has already created and it’s name is customers ) we type :Īs you see the coherence was reading default cache configuration file instead of our cache config file. In this post I’ll explain how a member can use the existing cache ( customers cache which was created by the Eclipse project in this post )Īt the bottom of this screenshot you see that there is a prompt. Before read this post you should understand what was going on there.Īt the final in previous post the new member joined the cluster. In the previous post, I’ve explained how a member can join the existing cluster. ("With Index BUT Not in the filter:" + Timer.getDurationMSec()) ġ1391 milliseconds is almost same duration of without index. If we index the fields which are not used in the filter we won’t get any performance improvement.Ĭache.removeIndex(new ReflectionExtractor("getFirstName")) Ĭache.removeIndex(new ReflectionExtractor("getAge")) Ĭache.addIndex(new ReflectionExtractor("getCitizenNumber"), true, null) In order to get the filtered data set faster we can use the indexed object fields which are used in the filter. ("With Two Indexes:" + Timer.getDurationMSec()) We can use age field as well in the index:Ĭache.addIndex(new ReflectionExtractor("getAge"), false, null) We know that our filter uses two fields, one of them is the firstname which was just before indexed and the other one is the age. While creating this index we did not use sorted index because we just looking for equalities, but we’ll use sorted index in the next one.Īs you see, with one index, entrySet method double times faster than the previous one, without index. Select * from people where ( firstName="Hugo" and age>50 ) or ( ( firstName="William" and age 20 ”. If we convert this filter clause to an sql query it would be : Then, filter is created, pay a little bit more attention to here, uppermost the orfilter was used and two and filters was used in the filter. New EqualsFilter("getFirstName","William"),įirstly, I connected to the cluster and cache, after that 2 millions of people object is generated, they all put into the cache. New EqualsFilter("getFirstName", "Hugo"), ("Cache loaded:"+cache.size()+" elements.") PersonGenerator pg = new PersonGenerator() Ĭache.putAll(pg.getRandomPeople(2000000)) NamedCache cache = CacheFactory.getCache("persons") Likewise, in coherence when you wish the get data you should decide correctly whether use it or not.Īnyway, in this blog post I will carry out basic filter operations with and without index. For example, when using the Oracle database and if you use a filter to retrieve data but its selectivity is close to 1, Oracle cost based optimizer can choose to not use the indexes because it’s not necessary since each index operations requires one more I/O. If you wish to retrieve all the items in the cache, likely index are not appropriate for you same as when you use database index. In the coherence, indexes are used for same purpose as well, fast access to filtered data. In a traditional database we use the index to access filtered data as quickly as possible.
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