Showing posts with the label Top NoSQL Interview Questions

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How to Check Column Nulls and Replace: Pandas

Here is a post that shows how to count Nulls and replace them with the value you want in the Pandas Dataframe. We have explained the process in two steps - Counting and Replacing the Null values. Count null values (column-wise) in Pandas ## count null values column-wise null_counts = df.isnull(). sum() print(null_counts) ``` Output: ``` Column1    1 Column2    1 Column3    5 dtype: int64 ``` In the above code, we first create a sample Pandas DataFrame `df` with some null values. Then, we use the `isnull()` function to create a DataFrame of the same shape as `df`, where each element is a boolean value indicating whether that element is null or not. Finally, we use the `sum()` function to count the number of null values in each column of the resulting DataFrame. The output shows the count of null values column-wise. to count null values column-wise: ``` df.isnull().sum() ``` ##Code snippet to count null values row-wise: ``` df.isnull().sum(axis=1) ``` In the above code, `df` is the Panda

Big Data: Top NoSQL Interview Questions (2 of 5)

1) What is most important character of NoSQL? High Availability 2)Different types of NoSQL databases? Key-Value stores Column Stores Graph Stores Document Stores 3)What is oracle NoSQL database? Oracle NoSQL Database is a distributed key-value database designed to provide highly reliable, scalable, and available data storage across a configurable set of systems. 4)What is the DB engine being used in Oracle NoSQL database? Oracle NoSQL Database uses Oracle Berkeley DB Java Edition as the underlying data storage engine. 5)What is oracle NoSQL database? Oracle NoSQL Database is a shared-nothing system designed to run and scale on commodity hardware. Key-value pairs are hash partitioned across server groups known as shards. At any point in time, a single key-value pair is always associated with a unique shard in the system. 6) What are unique features of Oracle NoSQL? Oracle NoSQL Database leverages the high availability features in Berkeley DB in order to provide res