- A2005
- B 2007
- C 2009
- D 2011
Time Taken:
Correct Answer:
Wrong Answer:
Percentage: %
Answer: 2009
Explanation: MongoDB was initially released on February 11, 2009.
Answer: Document-oriented
Explanation: MongoDB is a document-oriented database.
Answer: Snapshot read concern
Explanation: MongoDB introduced the snapshot read concern in version 4.0, which made queries against an index atomic .
The CREATE statement in MySQL is used to create a new table. It specifies the table name, column names, data types, and any constraints or indexes associated with the table.
The AGGREGATE statement in MySQL is used to perform calculations on data, such as computing sums, averages, counts, and other aggregate functions.
The JOIN statement in MySQL is used to retrieve data from multiple tables by establishing relationships between them. It allows you to combine related data from different tables.
The SET NULL statement in MySQL is used to update a column with a NULL value. It allows you to set a column's value to NULL, indicating the absence of a value.
The COUNT function in MySQL is used to determine the number of rows in a result set or a specific column. It counts the number of records present in the specified context.
The PRIMARY KEY constraint in MySQL uniquely identifies each row in a table. It ensures that each value in the specified column or set of columns is unique and not NULL.
A trigger is a MySQL object that is used to automatically execute SQL statements in response to specific events, such as INSERT, UPDATE, or DELETE operations on a table. Triggers are defined to perform actions based on the occurrence of predefined events.