The Anatomy of an INSERT Query: A Deep Dive into the Behind-the-Scenes Process

Tarun Jain
3 min readAug 21, 2024

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· A Deep Dive into the Behind-the-Scenes Process
1. Client-side Processing:
2. Serialization:
3. Network Communication:
4. Server-side Processing:
5. Data Conversion:
6. Disk Storage:
7. Acknowledgement and Response:

A Deep Dive into the Behind-the-Scenes Process

When a user runs an INSERT query in a database, a complex series of steps take place behind the scenes to ensure the data is properly processed and stored. Let’s dive deep into the detailed workflow that unfolds when you execute this fundamental database operation:

1. Client-side Processing:

— The user initiates the INSERT query from a client-side application, such as a web application or a database management tool.
— The application constructs the SQL INSERT statement and gathers the necessary data to be inserted.
— The application typically stores the data in an in-memory data structure, such as an object or a collection, before preparing it for transmission.

2. Serialization:

— The application serializes the in-memory data structure into a format that can be transmitted over the network, such as JSON, XML, or a binary format.
— This serialization process converts the data structure into a sequence of bytes that can be sent to the database server.

3. Network Communication:

— The serialized data is then sent over the network from the client-side application to the database server.
— This communication typically occurs using a database protocol, such as SQL, JDBC, ODBC, or a custom protocol.
— The client-side application establishes a connection with the database server, often using a connection pool or a connection manager to optimize performance.
— The client-side application will typically serialize the JSON data into a string or a binary format before sending it to the database.

4. Server-side Processing:

— The database server receives the INSERT query and the serialized data from the client.
— The server-side database engine deserializes the incoming data, converting it into a format that the database can understand and process.

5. Data Conversion:

— The database engine performs various checks and validations on the data, such as type checking, constraint validation, and transaction management.
— It then converts the deserialized data into the appropriate internal data structures used by the database, such as tables, indexes, or other storage formats.
— This conversion process may involve mapping the client-side data types to the database-specific data types and potentially performing data transformations or normalization.
— On the server side, the database engine will deserialize the JSON data and convert it into an internal data structure that can be efficiently stored and queried.
— Many modern database management systems, such as PostgreSQL, MongoDB, and Couchbase, provide native support for storing and querying JSON data, often with specialized index structures and query languages (e.g., JSON path expressions).

— The database engine may also need to perform validation and type conversions to ensure the JSON data is compatible with the database’s schema and data types.

6. Disk Storage:

— After the data is converted into the database’s internal format, the database engine writes the data to the appropriate storage locations on the disk.
— This may involve updating indexes, logs, or other supporting data structures to ensure the integrity and consistency of the data.
— The database engine also manages transaction management, ensuring that the INSERT operation is either fully committed or rolled back, depending on the success or failure of the operation.

  • Primitive Data Types (string, int, date, etc.): For primitive data types, the database engine typically does not perform an additional serialization step before writing the data to disk, as the internal representation is already in a format suitable for storage.
    → The handling of primitive data types is typically well-supported and optimized by most database management systems.
  • JSON Data: When dealing with JSON data, the database engine may perform an additional serialization step to convert the internal data structure into a more optimized binary format before writing it to disk. This is because the internal representation of the JSON data may be in a format that is optimized for querying and manipulation but not necessarily for efficient storage.
    → When working with JSON data, the process is slightly more complex, as JSON is a hierarchical, semi-structured data format.

7. Acknowledgement and Response:

— Once the data is successfully stored on the disk, the database server sends an acknowledgment back to the client-side application, indicating the success or failure of the INSERT operation.
— The client-side application receives the response and can then update its internal state or provide feedback to the user as necessary.

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