Data, data en nog eens data

Author: tom

  • Just some updates on PLSQL

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    tom
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    From time to time, I just repeat old exercises. I do this to maintain my knowledge before it gets lost in the mist of time. One such areas is PLSQL. You never forget that PL SQL is used to maintain data on an Oracle database. But I do forget tiny details such as how to…

  • Some spatial functions in Oracle

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    tom
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    Oracle has a wonderful spatial module. The spatial data are stored in a database as so-called SDO_GEOMETRY data type. The data in such field look like: (MDSYS.SDO_GEOMETRY(2001,90112,MDSYS.SDO_POINT_TYPE(121235,484926,NULL),NULL,NULL)). In this structure, we see the so-called SRID. This SRID is here 90112. This indicates how a geographical location can be translated in coordinates. In this case we…

  • Oh my God: how good is open source

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    tom
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    A few days ago, I had to write a Python script that would enable us to write some data to an Oracle database. At first, I had no idea how to start. So, I downloaded a simple example script that I tried to run. The script was found via Google. This script looked like: import…

  • Swaps: currency swap and foreign exchange swap

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    tom
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    A little note from the area of financial economics. When going through the databases of a financial institution, one often encounters terms like foreign exchange swap, currency swap, interest swap. What is this anyway? I understand that a foreign exchange swap is related to a situation that one has foreign currency now, while it is…

  • the Zachman framework

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    tom
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    The Zachman framework is a nice example of so-called “IT Entreprise Architecture”. Such approach is directed at a comprehensive approach to the design, implementation and execution of IT strategy within an enterprise. The Zachman framework has two dimensions. The first dimension is the dimension of a party. Going from top to bottom, we show the…

  • Using IDA

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    tom
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    IBM launched InfoSphere Data Architect (IDA). This is a data modelling tool that acts as a competitor with Erwin and PowerDesigner. I played a bit with this tool to see what the capabilities are and in which areas these products are different from Erwin and PowerDesigner. As a general remark, I must say that I…

  • Create a description of a system

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    tom
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    From time to time, I must provide a scheme on how a system works. It is not really to find a technique in which all details can be shown. I was to make a differentiation between processes, like sending mail, databases and applications. I also want to indicate what techniques are used. Moreover, I would…

  • ElasticSearch: Restful services

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    As we have seen in a previous post, we communicate with the ElasticSearch server via messages that are sent to a server. On the other hand, the server responds in messages that are received by the client. This system of messages are labelled as s “RESTful” structure. This RESTful structure is based om messages that…

  • Curl and elasticSearch

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    tom
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    One of the most useful utilities is “curl”. This wonderful tool can be used to transfer data from one platform to another. It is relatively easy to install in Windows, whereas under linux, it is often already installed. It must be run from the terminal in Linux or the command line in Windows. One example…

  • ElasticSearch

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    tom
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    A new and popular nosql database is the Elastic Search database. This database is easy to install en easy to run. But is it easy to insert data and extract the outcomes? The principle of inserting data into ElasticSearch looks rather straight forward. One inserts json files. On the other hand, with filters, one may…