JSON processing capabilities are now available in Hive out-of-the-box. Each JSON object must be flattened to fit into one-line (does not support new-line characters).
Can we store JSON in Hive?
JSON (JavaScript Object Notation)
Using Hive as data store we can able to load JSON data into Hive tables by creating schemas.
Does Hive support JSON data type?
Apache Hive provides limited support to JSON files. You can store json data into Hive tables with string as a data type. There are 3rd party SerDe jars that you can use to create Hive table to import JSON files.
How do I import a JSON file into Hive?
Steps:
- Load JSON file from your home folder in HDFS to Hive.
- Login to the web console. …
- Copy /data/sample_json from HDFS to your home folder in HDFS. $ …
- Check the content of the sample_json directory. …
- It contains the file user_country. …
- Launch Hive by typing hive in the web console. …
- Use your database.
How does JSON handle Hive?
Analyze JSON documents in Hive
Use the get_json_object user-defined function (UDF). Use the json_tuple UDF. Use the custom Serializer/Deserializer (SerDe).
What is JSON format?
JavaScript Object Notation (JSON) is a standard text-based format for representing structured data based on JavaScript object syntax. It is commonly used for transmitting data in web applications (e.g., sending some data from the server to the client, so it can be displayed on a web page, or vice versa).
What is JSON SerDe in Hive?
The Hive JSON SerDe is commonly used to process JSON data like events. These events are represented as blocks of JSON-encoded text separated by a new line. The Hive JSON SerDe does not allow duplicate keys in map or struct key names.
Does Hive support unstructured data?
Hive is the replica of relational management tables. That means it stores structured data. However, Hive can also store unstructured data. Hive firstly loads the unstructured data from HDFS, creates a structure around it, and loads the data.
Is Hive an ETL tool?
Hive as an alternative to traditional ELT tools
Hive is a powerful tool for ETL, data warehousing for Hadoop, and a database for Hadoop.
How does Hive store XML data?
We can parse XML file in Hive using hivexmlserde. Create an external Hive table using hivexmlserde and put all xml file on that xml location(All xml file should be similar). Using this serde you need define start and end tag in create table statement and XPath of attributes you want to fetch.
What is the best way to load XML data into Hive?
3 Answers
- first you need to create single column table like CREATE TABLE xmlsample(xml string);
- after that you need to load data in local/hdfs to hive table like. LOAD DATA INPATH ‘———‘ INTO TABLE XMLSAMPLE;
- NEXT BY USING XPATH , XPATH_ARRAY , XPATH_STRING LIKE SAMPLE XML QUERIES..
What is struct in Hive?
structs. STRUCT in Hive is similar to the STRUCT in C language. It is a record type that encapsulates a set of named fields, which can be any primitive data type. We can access the elements in STRUCT type using DOT (.) notation.
What is Hive architecture?
Architecture of Hive
Hive is a data warehouse infrastructure software that can create interaction between user and HDFS. … The conjunction part of HiveQL process Engine and MapReduce is Hive Execution Engine. Execution engine processes the query and generates results as same as MapReduce results.
What is Regexp_replace in Hive?
Hive REGEXP_REPLACE Function
Searches a string for a regular expression pattern and replaces every occurrence of the pattern with the specified replacement.
How do I convert a string to a map in Hive?
str_to_map(text, delimiter1, delimiter2) – Creates a map by parsing text Split text into key-value pairs using two delimiters. The first delimiter seperates pairs, and the second delimiter sperates key and value. If only one parameter is given, default delimiters are used: ‘,’ as delimiter1 and ‘=’ as delimiter2 .
How do I use regexp<UNK>extract in Hive?
Syntax of regexp_extract function
index – n -> the nth group. If the n is bigger number than the actual group, the hive query will fail. Returns : The regexp_extract function returns a string value if the given pattern matches with the input string. Otherwise it will return a empty string.