A moving average is used to smooth out a time series. Computing moving average is a typical case of ordered data computing. Its basic computing method is to create a subset composed of N consecutive members of a time series, compute the average of the set and shift the subset forward one by one. The following example teaches you how to compute moving average in R language.…

Generally, Java programmers use poi or other open source packages to read and compute Excel data. These open source packages support low-level programming, which increases the overall learning cost and complicates the operation. But with the help of esProc, Java can avoid these problems.…

The join statements of the database can be used conveniently to perform the operation of alignment join. But sometimes the data is stored in the text files, and to compute it in Java alone we need to write a large number of loop statements. This makes the code cumbersome. Using esProc to help with programming in Java can solve the problem easily and quickly. Let’s look at how this works…

Cross-row and group computation often involves computing link relative ratio and year-on-year comparison. Link relative ratio refers to comparison between the current data and data of the previous period. Generally, it takes month as the time interval. For example, compare the sales amount of April with that of March, and the growth rate we get is the link relative ratio of April. Hour, day, week and quarter can also be used as the time…

Program development for data process often involves cross-database relational operations. The following example will illustrate Java’s method of handling these operations. sales table is in db2 database, employee table is in mysql database. The task is to join sales with employee through sellerid of sales table and eid of employee table, and filter out the data insales and employeethat…

It is common to use R language to group and summarize data of files. Sometimes we may find ourselves processing comparatively big files which have smaller computed result and bigger source data. We cannot load them wholly to the memory when we need to compute them. The only solutions could be batch importing and computing as well as result merging. We’ll use an example in the following to illustrate the way of R language to group and summarize data from big text files.

Here is a file,…

The computing power of SQL for mass structured data is complete, that is to say, it is impossible to find anything that SQL cannot compute. But its support layer is too low, which can lead to over-elaborate operation in practical application.…

Both esProc and R language are typical data processing and analysis languages with two-dimension…

Text files often brings headache for data analysts, are there any more convenient way for text files process? I prepare a case on how esProc deal with it, including import various text files; process big text files; visit text files of hdfs; as well as general operations, such as, file moving, deleting and checking whether a file exists. The following will illustrate these functions through examples. …

1. What OLAP We Need Indeed?

Category: Model

OLAP is an important constituent part of BI(business intelligence).

Understood literally, OLAP is online analytical processing, that is, users conduct analytical operation on real-time business data.

But, currently the concept of OLAP is seriously narrowed, and only it refers to operations such as conducting drilling,…