Sometimes you need to query a big text file, instead of the database. In those cases, you need to retrieve the file in a stream style to perform the query algorithm, in which parallel processing is needed to improve the computing performance. As Java lacks the class library for doing these, you have to use hardcoding t...
2015-08-10 1164 0
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With class library for merely simple parsing jobs, Java and reporting tools have difficulty in handling in-depth processing of semi-structured JSON data. esProc can help reduce the difficulty. A reporting tool will execute an esProc script in the same way as it executes a database stored procedure, pass parameters to t...
2015-08-06 1487 0
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esProc has lots of functions for processing structured and semi-structured data, as well as supports parsing expressions dynamically and using heterogeneous data sources. A reporting tool can pass in parameters, execute an esProc script the same way as it executes a database stored procedure and gets the result set thr...
2015-08-05 2623 0
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Encapsulated lots of functions for handling structured file computing, esProc can import text files with complex formats, implement cursor-style processing with big files and simplify multithreaded parallel processing. A Java application can pass in parameters, execute an esProc script the same way as it executes a dat...
2015-08-04 2404 0
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In esProc Parallel Computing: Multithreading, we learned how to increase efficiency through executing multithreaded computation. But besides using fork in the cellset code to achieve the multithreading type of parallel processing, esProc also builds the approach of parallel processing into some functions. Let’s find ou...
2015-07-31 1137 0
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esProc can simplify complex SQL-style queries using ordered sets, object-style access and stepwise computation. Usually there are two ways in which esProc is used: an independent one and one requiring integration with Java. Now let’s look at the first one through an example.
The sales table stores several years ...
2015-07-30 1735 0
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The data volume of the big data table is usually quite huge, which makes it impossible to retrieve all data from the big data table at once. In view of this, the data processing over big data table is usually to serve two purposes: With cs.fetch(), retrieve partial data each time or group & aggregate the data in th...
2015-07-29 1134 0
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Cluster computing can be used in esProc for performing complicated analytic and processing tasks. A cluster system consists of multiple parallel servers running on independent computers in a network. Every single computer in this network can send a parallel computing request to the cluster.
A cluster system enhances co...
2015-07-28 1578 0
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During data computing based on the table sequence, we can combine data from multiple table sequences together for use in the analysis and computation. For instance, use A.merge() to combine records of multiple table sequences in a certain order, or A.conj() to union them in order into a grand table, or JOIN functions, ...
2015-07-28 1292 0
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In addition to conventional databases, data sources of a reporting tool could also involve JSON files, MongoDB, txt files, Excel and HDFS files. Normally reporting tools can handle a single data source, but they are unable to manage various data sources requiring consolidation. Even though the data sources are of the s...
2015-06-29 1494 0
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It is difficult for SQL to handle order-related computations, for it does not support ordered sets. But as these computations are very common in real-world business, there are a lot of online discussions related to them. For example:
http://stackoverflow.com/questions/29750567/count-several-rows-as-one-if-the-next-row-...
2015-06-25 1106 0
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In esProc Charts: The Basics, esProc Charts: Coordinate Axes and Coordinate Transformation, as well as other documents explaining using chart elements in esProc charts, we discussed the method for plotting charts in esProc. To display charts on web, however, hyperlinks are often required. Here we’ll see how to design ...
2015-06-24 1095 0
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In real-world business, many computing tasks require transposing rows and columns dynamically. There are a lot of discussions around the operation in online IT groups and forums. Below lists some of them:
http://www.dbforums.com/showthread.php?1628876-SQL-question-how-to-move-two-column-data-to-one-column-data
https://...
2015-06-23 1312 0
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Sometimes you need to reference data sources dynamically through a parameter, merge data sources into one, or dynamically pass data source name to a subreport/Table control. Often reporting tools – especially those with support for single data source, such as BIRT and Jasper – have to use a high-level language to...
2015-06-18 4292 0
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Java provides functions for handling the basic file processing, which refers to the retrieval of small text files, in a simple, unstructured way. But in handling files requiring structured format, holding data of various formats and having particular requirements, or big files that cannot be entirely loaded into memory...
2015-06-17 1275 0
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