AI-Mock-Interviewer/PDF_Extracted_Data huggingface dataset:
Question: what are the considerations you need to have when using scala streams?
Answer: Streams in Scala are a type of lazy collection, which are created using starting element and then recursively generated using those elements. Streams  are like a List, except that, elements are added only when they are accessed, hence lazy. Since streams are lazy in terms of adding elements, they can be unbounded also, and once the elements are added, they are cached. Since Streams can be unbounded, a nd all the values are computed at the time of access, programmers need to be careful on using methods  which  are not transformers,  as it may  resul t in java.lang.OutOfMemoryErrors. stream.max stream.size stream.sum 62. Differentiate between Array and List i n Scala. List is an immutable recursive data structure whilst array is a sequential mutable data structure. Lists are covariant whilst array are invariants.The size of a list automatically increases or decreases based on the operations that are performed o n it i.e. a list in Scala is a variable -sized data structure whilst an array is fixed size data structure.
Question: which keyword is used to define a function in scala?
Answer: A function is defined in Scala using the def keyword. This may sound familiar to Python de velopers as Python also uses def to define a function.
Question: follow me https www you tubecomcsauravagarwal64 what is monad in scala?
Question: is scala statically typed language?
Answer: Yes, Scala is a statically -typed language.
Question: what is statically typed language and what is dynamically typed language?
Answer: Statically -Typed Language means that Type checking is done at compile - time by compiler, not a t run-time. Dynamically -Typed Language means that Type checking is done at run-time, not at compile -time by compiler.
Question: what is the difference between un apply and apply when would you use them?
Question: what is unit in scala?
Question: what is the difference between java s void and scala sun it unit is something like java s void
Question: what is app in scala?
Question: what is the use of scala sapp?
Answer: The main advantage of using App is that we dont need to write main method. The main drawback of using App is that we should use same name args to refer command line argument because scala.Apps main() method uses this name.
Question: what are option some and none in scala?
Answer: Option is a Scala generic type that can either be some generic value or none.  Queue often uses it to represent prim itives that may be null.
Question: what is scala future?
Question: how it differs from java s future class?
Answer: The main and foremost difference between Scalas Future and Javas Future class is that the later does not provide promises/callbacks operations. The only way to retrieve the result is Future.get () in Java.
Question: what do you understand by diamond problem and how does scala resolve this?
Answer: Follow  Me : https://www.yo utube.com/c/SauravAgarwa l Multiple inheritance problem is referred to as the Deadly diamond problem or diamond problem. The inability to decide on which implementation of the method to choose is referred to as the Diamond Problem in Scala. Suppose say classes B and C both  inherit from class A, while class D inherits from both class B and C. Now while implementing multiple  inheritance if B and C override some method from class A, there is a confusion and dilemma always on which implementation D should inherit. This is what  is referred to as diamond problem. Scala resolves diamond problem through the concept of Traits and class linearization rules.
Question: what is the difference between in java and scala?
Question: what is repl in scala what is the use of scala s repl?
Question: what are the similarities between scala sint and java s java lang integer?
Question: what are the differences between scala sint and java s java lang integer?
Question: what is the relationship between int and rich in tin scala?
Question: applications?
Question: what is the use of auxiliary constructors in scala?
Answer: Auxiliary Constructor is the secondary constructor in Scala declared using the keywords this and def. The main pu rpose of using auxiliary constructors is to overload constructors. Just like in Java, we can provide implementation for different kinds of constructors so that the right one is invoked based on the requirements. Every auxiliary constructor in Scala should differ in the number of parameters or in data types.
Question: how does yield work in scala?
Answer: The yield keyword if specified before the expression, the value returned from  every  expression,  will be  returned  as  the  collection.  The  yield keyword is very useful, when there is a need, you want to use the return value of expression.  The collection returned can be used the normal collection and iterate over in another loop.
Question: what are the different types of scala identifiers there four types of scala identifiers
Answer: Follow  Me : https://www.yo utube.com/c/SauravAgarwa l Alpha numeric identifiers Operator identifiers Mixed identifiers Literal identifiers
Question: what are the different types of scala literals?
Question: what is sbt what is the best build tool to develop play and scala applications?
Question: what is the difference between and in scala?
Answer: :: and ::: are methods available in List class. :: method is used to append an element to the beginning of the list. And  ::: method is used to concatenate the elements of a given list in front of this list. :: method works as a cons operator for List class.  Here cons stands for construct. ::: method works as a concatenation operator for List class.
Question: follow me https www you tubecomcsauravagarwal88 what is the difference between and in scala?
Answer: #:: and #::: are methods available in Stream class #:: method words as a cons operator for Stream clas s. Here cons stands for construct. #:: method is used to append a given element at beginning of the stream. #::: method is used to concatenate a given stream at beginning of the stream.
Question: what is the use of in scala based applications?
Question: this three question marks is not an operator a method in scala it is used to mark a method
Question: how scala supports both highly scalable and highly performance applications?
Answer: As Scala supports Multi -Paradigm Programming(Both OOP and FP) and uses Actor Concurrency Model, we can develop very highly Scalable and high -performance applications very easily.
Question: what are the available buildtools to develop play and scala based applications?
Answer: Follow  Me : https://www.yo utube.com/c/SauravAgarwa l The following three are most popular available Build Tools to develop Play and Scala Applications: SBT Maven Gradle
Question: what is either in scala?
Question: what are left and right in scala explain either left right design pattern in scala?
Question: how many public class files are possible to define in scala source file?
Question: what is nothing in scala?
Question: and nothing in scala?
Question: how to you create singleton classes in scala?
Question: what is option and how is it used in scala?
Question: what is the difference between a call by value and call by name parameter?
Answer: The main difference between a call -by-value and a call -by-name parameter is that the former is computed before calling the function, and the later is evaluated when accessed.
Question: follow me https www you tubecomcsauravagarwal101 what is default access modifier in scala does scala have public keyword?
Question: is scala an expression based language or statement based language?
Question: is java an expression based language or statement based language?
Question: mention some keywords which are used by java and not required in scala?
Answer: Java u ses the following keywords extensively: public keyword - to define classes, interfaces, variables etc. static keyword - to define static members.
Question: why scala does not require them?
Question: what is sq oop?
Question: why is the default maximum mappers are 4insqoop?
Answer: As of my knowledge, the default number of mapper 4 is followed by minimum concurrent task for one machine. We will lead to set a higher number of concurrent tasks, which can result in faster job completion.
Question: is it possible set speculative execution in sq oop?
Question: what causes of had oop throw classnotfoundexception while sq oop integration?
Answer: The most causes of that the supporting library (like connectors) was not updated in sqoop's library path, so we need to update it on that specific path.
Question: how to view all the databases and tables in rdbms from sq oop?
Answer: Using below commands we can, sqoop -list-databases sqoop -list-tables
Question: how to view table columns details in rdbms from sq oop?
Question: to a hive table so how do we resolve it?
Answer: you can specify the --hive-overwrite option to indicate that existing table in hive must be replaced. After your data is imported into HDFS or this step i s omitted
Question: what is the default file format to import data using apache sq oop?
Question: how do i resolve a communications link failure when connecting to mysql?
Question: how do i resolve an illegalargumentexception when connecting to oracle?
Answer: This could be caused a non -owner trying to connect to the table so prefix the table name with the schema, for example Sche maName.OracleTableName. 11)  What's causing  this  Exception  in  thread main
Question: java lang incompatible class change error when running noncdhhadoopwithsqoop?
Question: to import the tables one by one?
Answer: This can be accomp lished using the import -all-tables import command in Sqoop and by specifying the exclude -tables option with it as follows - sqoop import -all-tables --connect -username -password --exclude -tables Table298, Table 123, Table 299
Question: does apache sq oop have a default database?
Answer: Yes, MySQL is the default database. bigdatascholars.blogspot.com/2018/08/sqoop -interview -question -and-answers.html
Question: how can i import large objects blob and clob objects in apache sq oop?
Question: manner?
Question: what is the difference between sq oop and dis tcp command in had oop?
Answer: Both distCP (Distributed Copy in Hadoop) and Sqoop transfer data in parallel but the only difference is that distCP command can transfer any kind of data from one Hadoop cluster to another whereas Sqoop transfers data between RDBMS and other components in the Hadoop ecosystem like  HBase, Hive, HDFS, etc.
Question: what is sq oop meta store?
Answer: Sqoop metastore  is a shared metadata repository for remote users to define and execute saved jobs created using sqoop job defined in the metastore. The sqoop -site.xml should be configured to connect to the metastore. 18) What is the significance of using -split-by clau se for running parallel import tasks in Apache
Question: sq oop?
Question: parallel map reduce tasks why?
Answer: Hadoop MapReduce cluster is configured to run a maximum of 4 parallel MapReduce tasks and the sqoop import can be configured with number of parallel tasks less than or equal to 4 but not more than4. 21) You successfully imported a table u sing Apache Sqoop to HBase but when you query the
Question: table it is found that the number of rows is less than expected what could be the likely reason?
Question: row into rdbms in which the columns are defined as not null?
Answer: Using the -input -null-string parameter, a default value can be specified so that the row gets inserted with the default value for the column that it has a NULL value in HDFS.
Question: how will you synchronize the data in hdfs that is imported by sq oop?
Question: what are the relational databases supported in sq oop?
Question: what are the destination types allowed in sq oop import command?
Answer: Currently Sqoop Supports data imported into below services. HDFS Hive HBase HCatalog Accumulo
Question: is sq oop similar to dist cp in had oop?
Question: what are the majorly used commands in sq oop?
Question: possible speed what can you do?
Question: what might be the root cause and fix for this error scenario?
Question: what is the importance of eval tool?
Question: what is the process to perform an incremental data load in sq oop?
Question: what is the significance of using compress codec parameter?
Answer: To get the out file of a sqoop import in formats other than .gz like .bz2 compressions when we use the -compress -code parameter.
Question: can freeform sql queries be used with sq oop import command if yes then how can they
Question: be used?
Answer: Follow  Me : https://www.yo utube.com/c/SauravAgarwa l Sqoop allows us to use fre e form SQL queries with the import command. The import command should be used with the -e and - query options to execute free form SQL queries. When using the -e and -query options with the import command the -target dir value must be specified.
Question: what is the purpose of sq oop merge?
Answer: The merge tool combines two datasets where entries in one dataset should overwrite entries of an older dataset preserving only the newest version of the records between both the data sets.
Question: how do you clear the data in a staging table before loading it by sq oop?
Answer: By specifying the -clear -staging -table option we can clear the staging table before it is loaded. This can be done again and again till we get proper data in staging.
Question: how will you update the rows that are already exported?
Question: what is the role of jdbc driver in asq oop setup?
Answer: To connect to different relational databases sqoop needs a connector. Almost every DB vendor makes this connecter available as a JDBC driver which is specific to that DB. So Sqoop needs the JDBC driver of each of the database it needs to interact with.
Question: when to use targetdir and warehouse dir while importing data?
Question: sync with the data in hdfs imported by sq oop?
Answer: Follow  Me : https://www.yo utube.com/c/SauravAgarwa l sqoop can have 2 approaches. To use the --incremental parameter with append option where value of some columns are checked and only in case of modified values the row is imported as a new row. To use the --incre mental parameter with lastmodified option where a date column in the source is checked for records which have been updated after the last import.
Question: is it possible to add a parameter while running a saved job?
Answer: Yes, we can add an argument to a saved job a t runtime by using the --exec option sqoop job --exec jobname -- -- newparameter 41) sqoop takes a long time to retrieve the minimum and maximum values of columns
Question: mentioned in split by parameter how can we make it efficient?
Answer: We can use the --boundary -query parameter in which we specify the min and max value for the column based on which the split can happen into multiple mapreduce tasks. This makes it faster as the query inside the - boundary -query parameter is executed first and the job is ready with t he information on how many mapreduce tasks to create before executing the main query.
Question: how will you implement all or nothing load using sq oop?
Answer: Using the staging -table option we first load the data into a staging table and then load it to the final target table only if the staging load is successful.
Question: deleted?
Answer: Follow  Me : https://www.yo utube.com/c/SauravAgarwa l Truncate the target table and load it again. 45) How can we load to a column in a relational table which is not null but the incoming value
Question: from hdfs has a null value?
Answer: By using the -input -null-string parameter we can specify a default value and that will  allow the row to be inserted into the target table.
Question: how can you schedule asqoopjobusingoozie?
Answer: Oozie has in -built sqoop actions inside which we can mention the sqoop commands to be executed. 47) Sqoop imported a table successfully to HBase but it  is found that the number of rows is
Question: fewer than expected what can be the cause?
Answer: Some of the imported records might have null values in all the columns. As Hbase does not allow all null values in a row, those rows get dropped. 48) How can you force sqoop to execute a free form Sql query only once and import the rows
Question: serially?
Question: sqooprunsonly4 what can be the reason?
Answer: The Mapreduce cluster is configured to run 4 parallel tasks. So the sqoop command must have number of parallel tasks less or equal to that of the MapReduce cluster. 50) What happe ns when a table is imported into a HDFS directory which already exists using
Question: the append parameter?
Answer: Follow  Me : https://www.yo utube.com/c/SauravAgarwa l Using the --append argument, Sqoop will import data to a temporary directory and then rename the files into the normal target directory in a manner that doe s not conflict with existing filenames in that directory. 51) How to import only the updated rows form a table into HDFS using sqoop assuming the
Question: source has last update timestamp details for each row?
Answer: By using the lastmodified mode. Rows where the check c olumn holds a timestamp more recent than the timestamp specified with --last-value are imported. 52) Give a Sqoop command to import all the records from employee table divided into groups of records by the values in the column department_id. $ sqoop impor t --connect jdbc:mysql://DineshDB --table EMPLOYEES  --split-by dept_id -m2
Question: what does the following query do?
Question: what is the importance of conditions in sq oop?
Question: can sq oop run without a had oop cluster?
Answer: To run Sqoop commands, Hadoop is a mandatory prerequisite. You cannot run sqoop commands without the Hadoop libraries.
Question: is it possible to import a file in fixed column length from the database using sq oop import?
Question: how to use sq oop validation?
Answer: You can use this parameter ( --validate) to validate the counts between whats imported/exported between RDBMS and HDFS.
Question: how to pass sq oop command as file arguments in sq oop?
Answer: specify an options file, simply create an options file in a convenient locat ion and pass it to the command line via - -options -file argument. eg: sqoop --options -file /users/homer/work/import.txt --table TEST
Question: is it possible to import data apart from hdfs and hive?
Answer: Sqoop supports additional import targets beyond HDFS and Hive. Sqoop can also import records into a table in HBase and Accumulo.
Question: follow me https www you tubecomcsauravagarwal60 is it possible to use sq oop direct command in h base?
Answer: This function is incompatible with direct import. But Sqoop can d o bulk loading as opposed to direct writes. To use bulk loading, enable it using --hbase -bulkload.
Question: can i configure two sq oop command so that they are dependent on each other like if the
Question: first sq oop job is successful second gets triggered if first fails second should not run?
Answer: No, using sqoop commands it is not possible, but You can use oozie for this. Create an oozie workflow. Execute the second action only if the first action succeeds.
Question: what is uber mode and where is the settings to enable in had oop?
Question: what is hive?
Question: why do we need hive?
Question: what is a meta store in hive?
Question: is hive suitable to be used for oltp systems why?
Answer: No, Hive does not provide insert and update at row level. So it is not suitable for OLTP system.
Question: can you explain about acid transactions in hive?
Question: what are the types of tables in hive?
Question: what kind of data warehouse application is suitable for hive?
Answer: Hive is not considered as a full database. The design rules and regulations of Hadoop and HDFS put restrictions on what Hive can do.Hive is most s uitable for data warehouse applications. Where Analyzing the relatively static data, Less Responsive time and No rapid changes in data. Hive does not provide fundamental features required for OLTP (Online Transaction Processing). Hive is suitable for data warehouse applications in large data sets.
Question: explain what is a hive variable what do we use it for?
Question: how to change the warehouse dir location for older tables?
Question: what are the types of meta store available in hive?
Answer: There are three types of meta stores available in Hive. Embedded  Metastore (Derby) Local Metastore Remote Metastore.
Question: is it possible to use same meta store by multiple users in case of embedded hive?
Question: if you run hive server what are the available mechanism for connecting it from application?
Question: what is ser de in apache hive?
Question: which classes are used by the hive to read and write hdfs files?
Question: give examples of these r de classes which hive uses to serialize and deserialize data?
Answer: Hive currently use these SerDe classes to serialize and Deserialize data: MetadataTypedColumnsetSerDe: This SerDe is used to read/write delimited records like CSV, tab - separated control -A separated records (quote i s not supported yet.) ThriftSerDe: This SerDe is used to read or write thrift serialized objects. The class file for the Thrift object must be loaded first. DynamicSerDe: This SerDe also read or write thrift serialized objects, but it understands thrift DD L so the schema of the object can be provided at runtime. Also it supports a lot of different protocols, including TBinaryProtocol, TJSONProtocol, TCTLSeparatedProtocol(which writes data in delimited records).
Question: how do you write your own custom ser de and what is the need for that?
Question: what is object inspector functionality?
Question: what is the functionality of query processor in apache hive?
Answer: This component implements the processing framework for c onverting SQL to a graph of map or reduce jobs and the execution time framework to run those jobs in the order of dependencies and the help of metastore details.
Question: what is the limitation of derby database for hive meta store?
Answer: With derby database, you can not have multiple connections or multiple sessions instantiated at the same time. Derby database runs in the local mode and it creates a log file so that multiple users cannot access Hive simultaneously.
Question: what are managed and external tables?
Question: what are the complex data types in hive?
Question: how does partitioning help in the faster execution of queries?
Answer: With the help of partitioning, a sub directory will be created with the name of the partitioned column and when you perform a query using the WHERE clause, only the particular sub -directory will be scanned instead of scanning the whole table. This gives yo u faster execution of queries.
Question: how to enable dynamic partitioning in hive?
Question: what is bucket ing?
Question: how does bucket ing help in the faster execution of queries?
Question: how to enable bucket ing in hive?
Answer: By default bucketing is disabled in Hive, you can enforce to enable it by setting the below property set hive.enforce.bucketing = true;
Question: what are the different file formats in hive?
Answer: Every file format ha s its own characteristics and Hive allows you to choose easily the file format which you wanted to use. There are different file formats supported by Hive Follow  Me : https://www.yo utube.com/c/SauravAgarwa l 1. Text File format 2. Sequence File format 3. Parquet 4. Avro 5. RC file format 6. ORC
Question: how is ser de different from file format in hive?
Question: what is regex ser de?
Question: how is orc file format optimised for data storage and analysis?
Answer: ORC stores collections of rows in one file and within the collection the row data will be stored in a columnar  format. With columnar format, it is very easy to compress, thus reducing a lot of storage cost. While querying also, it queries the par ticular column instead of querying the whole row as the records are stored in columnar format. Follow  Me : https://www.yo utube.com/c/SauravAgarwa l ORC has got indexing on every block based on the statistics min, max, sum, count on columns so when you query, it will skip the blocks based on the indexing.