Table of Contents
- 1 What is the use of row format delimited in Hive?
- 2 What is the default field delimiter in Hive?
- 3 What is row format delimited fields terminated by?
- 4 Is Hive suitable to be used for OLTP systems Why?
- 5 What will sqoop use as field delimiters in the hive table data file?
- 6 Why we use external tables in Hive?
- 7 Is there a good character for delimiting in Hadoop/Hive?
- 8 What is the difference between row format delimited and fields terminated by?
What is the use of row format delimited in Hive?
A list of key-value pairs used to tag the SerDe definition. The DELIMITED clause can be used to specify the native SerDe and state the delimiter, escape character, null character and so on. Used to define a column separator. Used to define a collection item separator.
What is the default field delimiter in Hive?
In Hive, by default, each fields are delimited by CTRL-A (ie Octal \001). If a field is a complex type containing complex type(we call this as Nested Type), then delimiters CTRL-B (\002) followed by CTRL-C(\003), CTRL-D(\004), etc… are used depending on the depth of the nesting.
What is u0001 delimiter in Hive?
” is a single character Ctrl-A. What do you have in your data file as the delimiter? A single ctrl-A or 6 characters ”? The delimiter in Hive must be a single character, and actually Ctrl-A is the default.
Which of the following row format field is mandatory while creating an external table in Hive?
LOCATION is mandatory for creating external tables. LOCATION indicates the location of the HDFS flat file that you want to access as a regular table.
What is row format delimited fields terminated by?
comma
ROW FORMAT should have delimiters used to terminate the fields and lines like in the above example the fields are terminated with comma (“,”). The default location of Hive table is overwritten by using LOCATION.
Is Hive suitable to be used for OLTP systems Why?
Is Hive suitable to be used for OLTP systems? No Hive does not provide insert and update at row level. So it is not suitable for OLTP system.
What is the meaning of row format delimited?
The clause ROW FORMAT DELIMITED FIELDS TERMINATED BY ‘\001’ means that Hive will use the ^A character to separate fields. Similarly, the character \002 is the octal code for ^B. The clause ROW FORMAT DELIMITED COLLECTION ITEMS TERMINATED BY ‘\002’ means that Hive will use the ^B character to separate collection items.
What is the importance of .hiverc file?
hql What is the importance of . hiverc file? It is a file containing list of commands needs to run when the hive CLI starts. For example setting the strict mode to be true etc.
What will sqoop use as field delimiters in the hive table data file?
What is the sqoop default field delimiter? comma is the default delimiter.
Why we use external tables in Hive?
External tables are an excellent way to manage data on the Hive since Hive does not have ownership of the data stored inside External tables. In case, if the user drops the External tables then only the metadata of tables will be removed and the data will be safe.
What is the use of external table in Hive?
An external table is a table for which Hive does not manage storage. If you delete an external table, only the definition in Hive is deleted. The data remains. An internal table is a table that Hive manages.
What is the use of rowrow format delimited in hive?
Row format delimited is used to tell hive that my incoming file is delimited .fields terminated by is used to tell hive by which delimiter the columns are delimited. Learn everything about hive and ADVANCE hive from here.
Is there a good character for delimiting in Hadoop/Hive?
Since tab is a fairly common character in text, and Hadoop/Hive is used a lot for handling text, it is tough to find a good character for delimiting. We have faced the same in our data load into hadoop clusters. What we did, added \\ whenever we saw the delimiter is included within a data fields and added the below in the table definition.
What is the difference between row format delimited and fields terminated by?
“Row format delimited” is used to store the data in the hdfs row per line. “fields terminated by” is used to store the data in the hdfs where the columns are separated by the specified character. Hope got idea about this…. This hints HIVE about format of the data i.e to how to read and write data from a hive table.
How do I load a CSV file into a hive table?
I am trying to load a CSV file into a Hive table like so: CREATE TABLE mytable ( num1 INT, text1 STRING, num2 INT, text2 STRING ) ROW FORMAT DELIMITED FIELDS TERMINATED BY “,”; LOAD DATA LOCAL INPATH ‘/data.csv’ OVERWRITE INTO TABLE mytable; The csv is delimited by an comma (,) and looks like this: