How do I remove an RDD element?

How do I remove an RDD element?

1. just use filter no? – Markon. Dec 4 ’15 at 14:33.
2. In Java I use a filter : . filter(new Function() { public Boolean call(CassandraRow row) throws Exception {return row. getString(“value”). equals(whatIWant); } }).
3. what would be the argument of the lambda function. key, value or both? – Bob.

How do you delete a column in Spark?

Spark DataFrame provides a drop() method to drop a column/field from a DataFrame/Dataset. drop() method also used to remove multiple columns at a time from a Spark DataFrame/Dataset.

How do I remove a broadcast variable in Spark?

There is a way to remove broadcasted variables from the memory of all executors. Calling unpersist() on a broadcast variable removed the data of the broadcast variable from the memory cache of all executors to free up resources.

How do you delete a variable in Scala?

Unfortunately, you cannot delete a specific variable in Scala REPL. [1] What you can do is assigning a new value to override an existing variable. Scala REPL also provides a command :reset to remove all variables.

How do I remove RDD from Spark?

You should call thisRDD. unpersist() to remove the cached data. Actually here, you won’t have any data cached, it would be only marked as ‘to be cached’ in the RDD execution plan. You can easily check the persisted data and the level of persistence in the Spark UI using the address http://:4040/storage.

What is Spark Foldbykey?

Merge the values for each key using an associative function “func” and a neutral “zeroValue” which may be added to the result an arbitrary number of times, and must not change the result (e.g., 0 for addition, or 1 for multiplication.).

How do I delete a DataFrame in spark?

Spark >= 2. x

1. Drop a specific table/df from cache spark.catalog.uncacheTable(tableName)
2. Drop all tables/dfs from cache spark.catalog.clearCache()

How do I get rid of spark?

Remove data from Spark & request data copy or deletion

1. On Mac, click Spark > Preferences > Remove My Data From Spark.
2. On iOS, open Settings, tap your email address at the top and select Remove My Data From Spark.
3. On Android, go to Settings, select your email address and tap Remove My Data From Spark.

Is broadcast variable a shared variable?

Sometimes, a variable needs to be shared across tasks, or between tasks and the driver program. Spark supports two types of shared variables: broadcast variables, which can be used to cache a value in memory on all nodes, and accumulators, which are variables that are only “added” to, such as counters and sums.

What is a broadcast variable in Spark?

A broadcast variable. Broadcast variables allow the programmer to keep a read-only variable cached on each machine rather than shipping a copy of it with tasks. Spark also attempts to distribute broadcast variables using efficient broadcast algorithms to reduce communication cost.

How do you delete in spark shell?

In order to delete a file or a directory in Spark, use delete() method of Hadoop FileSystem. delete() method of FileSystem will be used to delete both File and a Directory.

What is flatten in Scala?

The flatten function is applicable to both Scala’s Mutable and Immutable collection data structures. The flatten method will collapse the elements of a collection to create a single collection with elements of the same type.

How to delete a row from a Dataframe in spark?

Dataframes in Apache Spark are immutable. SO you cannot change it, to delete rows from data frame you can filter the row that you do not want and save in another dataframe. Show activity on this post.

How to delete rows in pyspark Dataframe based on multiple conditions?

In this article, we are going to see how to delete rows in PySpark dataframe based on multiple conditions. Here we are going to use the logical expression to filter the row. Filter () function is used to filter the rows from RDD/DataFrame based on the given condition or SQL expression. It e valuates a list of conditions and returns a single value.

Is it possible to delete specific variables from the namespace?

I know that in Python (using del) and R (using rm ), you can delete specific variables from the namespace (aka environment or workspace). Show activity on this post.

How to delete a specific variable in Scala REPL?

I know that in Python (using del) and R (using rm ), you can delete specific variables from the namespace (aka environment or workspace). Show activity on this post. Unfortunately, you cannot delete a specific variable in Scala REPL. [1] What you can do is assigning a new value to override an existing variable.