Posts (page 130)
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3 min readThe opposite of REGEXP_LIKE in Oracle is REGEXP_INSTR. REGEXP_LIKE is used to determine if a string matches a specified regular expression pattern, while REGEXP_INSTR is used to find the position of a substring within a string that matches a specified regular expression pattern. In essence, REGEXP_LIKE is used to check for a match, while REGEXP_INSTR is used to find the location of a match within a string.
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6 min readTo connect to a Hadoop remote cluster with Java, you can use the Hadoop Java API. First, you need to create a Hadoop Configuration object and set the necessary configuration parameters such as the Hadoop cluster's address, file system type, and authentication credentials. Then, you can use this Configuration object to create a FileSystem object that represents the remote Hadoop file system.
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4 min readTo get the terminal size in Julia, you can use the TerminalSize function from the Libc module. This function returns a tuple containing the number of rows and columns in the terminal window. Here is an example code snippet to get the terminal size: using Libc rows, cols = Libc.TTY.getwinsize(STDOUT) println("Terminal size: rows=$rows, cols=$cols") Make sure to import the Libc module before calling the TerminalSize function.
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6 min readTo create a positive integer column in Oracle, you can specify the data type as "NUMBER" and set constraints to ensure that only positive integers are allowed. For example, you can use the following syntax when creating a table:CREATE TABLE table_name ( column_name NUMBER CONSTRAINT positive_integer_check CHECK (column_name > 0) );This will create a table with a column that can only store positive integers.
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6 min readTo download Hadoop files stored on HDFS via FTP, you can use an FTP client that supports HDFS connections. You will first need to configure the FTP client to connect to the HDFS servers. Once connected, you can navigate to the directory containing the Hadoop files you want to download and then simply transfer them to your local machine using the FTP client's download functionality.
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3 min readTo select a table using a string in Oracle, you can use dynamic SQL. This involves constructing a SQL statement as a string and then executing it using the EXECUTE IMMEDIATE statement. Firstly, you need to create the SQL statement as a string concatenating the table name with the rest of the SQL query. For example: SELECT * FROM || table_name Once you have the SQL statement as a string, you can execute it using the EXECUTE IMMEDIATE statement.
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3 min readIn Julia, you can join the elements of an array into a single string using the join() function. This function takes two arguments: the separator that you want to use between elements, and the array that you want to join.For example, if you have an array of strings called arr and you want to join them into a single string separated by commas, you can do so by calling join(arr, ",").
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7 min readTo process geo data in Hadoop MapReduce, you can start by parsing the input data to extract relevant geospatial information such as latitude, longitude, and other attributes. Once the data is extracted, you can then design a MapReduce job that utilizes algorithms and functions specific to geospatial analysis.During the mapping phase, you can partition the data based on geospatial attributes and perform transformations or computations on individual data points.
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5 min readTo create 3D interactive graphics in Julia, you can use packages like Makie.jl or GLVisualize.jl. These packages provide high-level graphics rendering capabilities that can be used to create interactive plots and visualizations in 3D.You can start by installing the necessary packages and dependencies using the Julia package manager. Once the packages are installed, you can create a 3D scene and add objects like points, lines, or surfaces to the scene.
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6 min readTo export data from Hive to HDFS in Hadoop, you can use the INSERT OVERWRITE DIRECTORY command in Hive. First, you need to create a table in Hive and insert the data into it. Then, you can use the INSERT OVERWRITE DIRECTORY command to export the data to a folder in HDFS. Make sure to specify the HDFS path where you want to export the data. This command will overwrite any existing data in the specified folder, so be careful when using it.
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7 min readCalculating Hadoop storage involves several factors such as the size of the data being stored, the replication factor, the overhead of the Hadoop Distributed File System (HDFS), and any additional storage requirements for processing tasks or temporary data.To calculate the total storage required for Hadoop, you need to consider the size of the data you want to store in HDFS.
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3 min readTo normalize the columns of a matrix in Julia, you can use the normalize function from the LinearAlgebra package. First, you need to import the LinearAlgebra package by using the following command: using LinearAlgebra.Next, you can normalize the columns of a matrix A by calling the normalize function on each column of the matrix. You can achieve this by using a for loop or by using the mapslices function.