Showing all posts by Aleksa Vukotic
March 21, 2012 | Software Consultancy
Event processing Language (EPL) enables us to write complex queries to get the most out of our event stream in real time, using SQL-like syntax.
EPL allows us to use full power of aggregation of the high volume event stream to get required results with the minimal latency. In this blog we are going to explore some aspects of numerical aggregation of data with high precision BigDecimal values. We will also demonstrate how you can add you own aggregation function to Esper engine and use them in EPL statements.
Most of the important players in this space are large IT corporations like Oracle and IBM with their commercial (read expensive) offerings.
While most of CEP products offer some great features, it’s license model and close code policy doesn’t allow developers to play with them on pet projects, which would drive adoption and usage of CEP in every day programming.
November 4, 2011 | Neo4j
In the previous post we compared the performance of fetching relationships from densely populated nodes using Neo4j native store and using lucene index.
We’ve seen that we can fetch the small subset of relationships from a super-node (containing ~1M relationships in total) directly from the Lucene index, the performance of the first run (cold-caches) is better then using the Neo store directly. The subsequent runs with caches warmed up show comparable performance, slightly in favor of direct Neo store fetching, sue to low level cache optimizations.
June 3, 2011 | Neo4j
Neo4J is one of the first graph databases to appear on the global market. Being open source, in addition to its power and simplicity in supporting graph data model it represents good choice for production-ready graph database.
However, there has been one area I have struggled to get good-enough performance from Neo4j recently – super nodes.