What is temporary table in hive?
A temporary table is a convenient way for an application to automatically manage intermediate data generated during a large or complex query execution.
Hive 0.14 onward supports temporary tables.
You can use them as a normal table within a user session..
What is a drawback of JSON columns?
The other major drawback is with performance of json columns. They are likely to always be slower than native datatype in 99% of circumstances but can be optimized with indexes on virtual columns. The query syntax is also a little bit more complex.
What is JSON and its advantages?
JSON offers the same kind of benefits that XML does for exchanging data in a heterogeneous environment, such as the following: JSON is self-describing. The syntax and hierarchical structure of the JSON strings can in some cases be interpreted by applications that do not already know what data to expect.
What is the limitation of JSON?
JSON parser limitsJSON parser limitJSON default valueJSON maximum valueMaximum Document Size4,194,304 bytes (4 MB)5,368,709,121 bytes (5 GB)Maximum Nesting Depth64 levels256 levelsMaximum Label String Length256 bytes8,192 (8 K) bytesMaximum Value String Length8,192 (8 K) bytes5,368,709,121 bytes (5 GB)2 more rows
Why is JSON used?
How do I view a temporary table in MySQL?
mysql> CREATE TEMPORARY TABLE t1 (c1 INT PRIMARY KEY) ENGINE=INNODB; Query INNODB_TEMP_TABLE_INFO to view the temporary table metadata. The TABLE_ID is a unique identifier for the temporary table. The NAME column displays the system-generated name for the temporary table, which is prefixed with “#sql”.
How do I make a temporary table?
The Syntax to create a Temporary Table is given below:To Create Temporary Table: CREATE TABLE #EmpDetails (id INT, name VARCHAR(25))To Insert Values Into Temporary Table: INSERT INTO #EmpDetails VALUES (01, ‘Lalit’), (02, ‘Atharva’)To Select Values from Temporary Table: SELECT * FROM #EmpDetails.Result: id. name. Lalit.
How long does MySQL temporary table last?
What are Temporary Tables? Temporary tables were added in the MySQL Version 3.23. If you use an older version of MySQL than 3.23, you cannot use the temporary tables, but you can use Heap Tables. As stated earlier, temporary tables will only last as long as the session is alive.
What is a MySQL session?
A session is just a result of a successful connection . Any MySQL client requires some connection settings to establish a connection and after the connection has been established it acquires a connection id (thread id) and some context which is called session.