Have you ever wondered about the concept behind spark dataframes? The spark dataframes are the extension version of the Resilient Distributed Dataset, with a high level of abstractions. Dataframes are similar to structured traditional databases with the advancement in optimization techniques.
In this blog, we will discuss apache spark dataframes.
What is Apache Spark?
Apache spark is a general open-source cluster computing framework. It is a leading platform for stream processing, batch processing, and large scale SQL. Spark is known as lightning-fast cluster computing in an Apache project. It is programmed in the Scala language. Spark lets you operate programs faster than Hadoop. Also, it is a quick data processing platform. Currently, Spark supports APIs in Python, Java, and Scala, and its core is suited for a set of high level and powerful libraries such as GraphX, SparkSQL, MLlib, and Spark Streaming.
- SparkSQL: SparkSQL provides querying data through hive query or via SQL. It also offers several data sources to work with SQL with code.
- GraphX: GraphX library supports the manipulation of graphs. It offers a uniform tool for graph computation, analysis, and ETL. It also supports standard graph libraries such as Pagerank.
- MLlib: It is a library of machine learning that supports several algorithms for regression, filtering, cluster classification, clustering, etc.
- Spark Streaming: Spark streaming provides real-time streaming data processing. It divides the input of data streams into batches.
What is Resilient Distributed Dataset?
Spark initiates the concept of Resilient Distributed Dataset, also known as RDD. It is a distributed and immutable collection of objects that can be run in parallel. There are two operations supported by RDD, transformations operations, and action operations. The transformations operations are performed on RDD, such as union, map, join filter, etc. The actions operations return a value on RDD, such as count, reduce, first, and many more.
Why do we need dataframes?
Apache Spark 1.3 version came with spark dataframes. There were two main limitations of the resilient distributed dataset. First is RDD cannot manage structured data, and second is RDD does not support any in-built optimization engine. The concept of Spark dataframes resolved the limitations of RDD.
Although, a Resilient Distributed Dataset cannot improve the system efficiently. So, to overcome the limitations of the Spark Resilient Distributed Dataset, Spark dataframes were introduced. Dataframes are organized into columns and rows. Each data frame column has an associated name and type.
Difference between Spark Resilient Distributed Dataset and Spark DataFrames?
The below table shows the difference between Spark RDD and Spark DataFrames.
|S.No.||Comparison factors||Spark Resilient Distributed Dataset||Spark DataFrames|
|1.||Definition||Low level of API||High level of abstraction|
|2.||Representation of data||It is distributed across various cluster nodes||It is a collection of named columns and rows.|
|3.||Optimization Engine||RDD does not support any in-built optimization engine||Utilization of optimization engine to create logical queries|
|5.||Performance limitation||Garbage collection and Java serialization||Support huge performance advancement as compared to RDD|
|6.||Interoperability and Immutability||Tracing of data lineage||It is not possible to get the object domain.|
What are the features of Spark DataFrames?
- Provides management of data structure. It supports a systematic approach to view data. When the data is being stored in data frames, it has some meaning to it.
- Spark dataframes provide scalability, flexibility, and various APIs such as java, python, R, and Scala programming.
- Utilization of optimization engines known as catalyst optimizers to process data in an efficient manner.
- Spark data frames can also process different sizes of data.
- Dataframes support different sets of data formats such as CSV, Cassandra, Avro, and ElasticSearch.
- Supports custom memory management and decreases the overload of garbage collection.
Check out: Apache Spark Developer Salary in India
Apache is very effective and fast. Apache Spark helps to compute an in-depth high volume of processing tasks in real-time. Dataframes are useful for developing query plans. Dataframe API improves and enhances the performance of Spark.
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Is Apache Spark a programming language?
If you have worked with Java and Python, you can’t have the same expectations from Apache Spark, since it is not a programming language. It is a data processing engine that is compatible with any situation and is available to use. The primary use of Spark stretches mainly to Big Data processing, keeping factors like scalability and speed in mind. Data analysts, engineers, and application developers use Spark every day to create queries and to transform data. ETL and EQL are some of the batch jobs that frequently take place in Apache Spark mainly for data processing. Spark is built on top of the Hadoop/HDFS framework that supervises and handles data supervision. This is done using Scala, which is a slightly functional alternative to Java. Spark also supports many programming languages like Python, Scala, and R.
What is the advantage of Apache Spark Dataframes?
The first advantage of dataframes is their data collection which is closely knitted in the form of columns. With fancy optimizations, Apache Spark resembles a database table. Furthermore, Cassandra, CSV, Avro, and Elasticsearch are some common data formats that Spark uses. Plus, storage systems like HIVE table, HDFS, and MySQL are also operated with Spark. The next advantage is Spark’s ability to work with Dataframe API, which allows it to use programming languages such as Scala, Python, and R. The last reason why Dataframes have an advantage is how they use Spark core to integrate with Big Data tools.
What are the limitations of Apache RDD?
To focus on the primary ones, Apache RDD lacks an optimisation engine. Catalyst optimizer and Tungsten engine are the optimizers that Spark operates on. Apache RDD is not compatible with these optimizers and can not implement them. Automatic optimization is also not possible with RDD. Apache RDD has less memory for storage. To accommodate itself with the storage space, RDD compresses to place itself in memory. Moreover, Spark RDD is deprived of run-time type safety which means it cannot calculate the errors when it compiles the program.