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Articles on Trending Technologies
Technical articles with clear explanations and examples
What are the features that were removed in MySQL 8.0?
Some of the features have become obsolete and have been removed from MySQL 8.0. When alternatives to these removed items are shown, they need to be used to avoid further complications.The ‘innodb_locks_unsafe_for_binlog’ system variable has been removed.The ‘READ COMMITTED’ isolation level can be used since it behaves in a similar way.After upgrading the system to MySQL version 8.0.3 or later, scripts that reference previous InnoDB INFORMATION_SCHEMA view names have to be upgraded.Some of the account management attributes have been removed. A few have been listed below:Instead of using ‘GRANT’ to create users, use ‘CREATE USER’.The query cache has been removed.The deprecated ...
Read MoreWhat are the options and variables introduced in MySQL 8.0?
Some of the options and variables newly introduced in MySQL 8.0 have been listed below:Com_clone: It refers to the number of CLONE statements. It was added in MySQL 8.0.2.Com_create_role: It refers to the number of CREATE ROLE statements that are used. It was added in MySQL 8.0.0.Com_drop_role: It refers to the number of DROP ROLE statements that were used. It was added in MySQL 8.0.0.Com_restart: It refers to the number of RESTART statements that were used. It was added in MySQL 8.0.4.Firewall_access_denied: It refers to the number of statements that were rejected by MySQL Enterprise Firewall. It was added in ...
Read MoreHow to Report MySQL Bugs or Problems
What is a bug?A bug is something that results in the program stalling or halting abruptly. This results in anomalies and causes complications, resulting in the task not getting complete. MySQL helps resolve these bugs, once they are reported.Some bugs have fixes since they would have been previously reported, and fixes would have been provided.Pre-requisitesBefore posting a bug report, it is important to verify that the bug hasn’t been reported already. For this purpose, look for the problem in the MySQL manual at https://dev.mysql.com/doc/. The manual is always updated with solutions to newly found issues.If there is a parsing error ...
Read MoreHow to Plot Cluster using Clustermaps class in Matplotlib
Let us suppose you have given a dataset with various variables and data points thus in order to plot the cluster map for the given data points we can use Clustermaps class.In this example, we will import the wine quality dataset from the https://archive.ics.uci.edu/ml/datasets/wine+quality.import matplotlib.pyplot as plt import numpy as np import seaborn as sns sns.set(style='white') #Import the dataset wine_quality = pd.read_csv(‘winequality-red.csv’ delimeter=‘;’)Let us suppose we have raw data of wine Quality datasets and associated correlation matrix data.Now let us plot the clustermap of the data, row_colors = wine_quality["quality"].map(dict(zip(wine_quality["quality"].unique(), "rbg"))) g = sns.clustermap(wine_quality.drop('quality', axis=1), standard_scale=1, robust=True, row_colors=row_colors, cmap='viridis')Plot the ...
Read MoreHow to align multiple plots in a grid using GridSpec Class in Matplotlib
Aligning the multiple plots in a grid can be very messy and it can create multiple issues like higher width and height or minimal width to align all the plots. In order to align all the plots in a grid, we use GridSpec class.Let us suppose that we have a bar graph plot and we want to align the symmetry of the plot in this sample.First Import all the necessary libraries and plot some graphs in two grids. Then, we will plot a constant error bar and a symmetric and asymmetric error bar on the first grid. In the second ...
Read MorePlotting regression and residual plot in Matplotlib
To establish a simple relationship between the observations of a given joint distribution of a variable, we can create the plot for the regression model using Seaborn.To fit the dataset using the regression model, we have to first import the necessary libraries in Python.We will create plots for each regression model, (a) Linear Regression, (b) Polynomial Regression, and (c) Logistic Regression.In this example, we will use the wine quality dataset which can be accessed from here, https://archive.ics.uci.edu/ml/datasets/wine+qualityExampleimport matplotlib.pyplot as plt import seaborn as sns from scipy.stats import pearsonr sns.set(style="dark", color_codes=True) #import the dataset wine_quality = pd.read_csv('winequality-red.csv', delimiter=';') #Plotting ...
Read MoreAlgorithm to construct an Expression Tree in Data Structure
Expression treesExpression trees are those in which the leaf nodes have the values to be operated, and internal nodes contain the operator on which the leaf node will be performed.Example4 + ((7 + 9) * 2) will have an expression tree as followsAlgorithm to Construct an Expression TreeLet T be the expression tree.If T is not NULL: If T->data is an operand: return T.data A = solve(T.left) B = solve(T.right) --> Calculate operator for 'T.data' on A and B, and call recursively, return calculate(A, B, T.data)How to construct an expression tree?To construct an Expression Tree for ...
Read MoreHow to Capture a pick event and use it to activate or deactivate Line Plots in Matplotlib
After enabling the pick event property of artists in Matplotlib, the task is to use the pick event to enable and disable the line plots for a given axis in a set of plots.In order to pick a specific line plot, we use Legend.We will use a Binary classification plot to create the ROC Curve. ROC curve or Receiver Operating Characteristics curve is used for diagnostics, weather prediction and other applications. It contains True Negative Rate (TPR) and False Positive Rate (FPR). Using ROC, we will create multiple plots of the curve.Let us Import the libraries first. Here ‘nbAgg’ is used ...
Read MoreHow to customize spines of Matplotlib figures?
When we plot a figure in Matplotlib, it creates four spines around the figure, top, left, bottom and right. Spines are nothing but a box surrounded with the pictorial representation of the grid which displays some ticks and tickable axes on left(y) and bottom(x).Let us see how to customize the spines in a given figure. We will create six figures to see and customize the spines for it.First import the required libraries for the workbook.import numpy as np import matplotlib.pyplot as pltLet us draw graph for sines, theta = np.linspace(0, 2*np.pi, 128) y = np.sin(theta) fig = plt.figure(figsize=(8, 6))Define the ...
Read MoreHow to customize the color and colormaps of a Plot in Matplotlib
To customize the color and colormaps of a plot, we can use the colormap property from the color library. There are two types of colormap we can create: (a) discrete colormap and (b) continuous colormap.We will first see how to create a discrete colormap followed by continuous colormap.In the example, we will use ‘iris’ dataset to create three plots such that the first plot uses the default colormap and the other two uses RGB map to create a mixed colored plot. However, we can create as many color maps as we have clusters.Exampleimport matplotlib.pyplot as plt import pandas as pd ...
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