Database Optimization

Gayathra Ranasinghe
3 min readDec 17, 2023

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Optimizing how your database reads data is an important way to improve performance. The faster data can be read, the better the user experience. You can optimize reading by using techniques like indexing, partitioning, optimizing queries, and caching. Indexing organizes the data so it’s easier to find, partitioning splits the data into smaller parts, queries can be made faster by using the right data types and calculations, and caching stores frequently accessed data for faster retrieval.

Indexing

Indexes in databases are like the indexes in books, they help you quickly find information without having to look through the entire database. They use keys from the database tables to search specific locations instead of the whole thing. This makes searches faster. For example, a table with columns for ID, Name, and Department could have an index with names and IDs, so you could easily search for someone’s name and find their corresponding ID and department.

Now the database can easily locate the names in the larger table quickly for searches using those IDs from the index.

Partitions

Data partitioning can also speed up database retrieval. There are two types: horizontal and vertical. Horizontal partitioning is more common and organizes rows by logical groupings in different tables, instead of storing them all in one big table. This reduces index size and makes it easier to write and retrieve data.

Instead of using an index table to search through the data, partitions split up large tables into smaller, more manageable ones. This makes it faster and easier to access the data you need.

To demonstrate how partitioning works, consider a large sales table that’s broken down into smaller tables. These smaller tables are easier to search through because the database doesn’t have to sift through as much data all at once. Partitioning makes it faster and more efficient to access the data you’re looking for.

Other optimization methods

In addition to indexes and partitioning, there are other ways to optimize your database’s performance. You can optimize your search queries for faster results and use your system’s cache to quickly access frequently used data. These methods can further improve the speed and efficiency of your database

Queries involve requesting data or information from a database, and optimizing them is crucial to ensure efficient performance and resource utilization. Regularly run queries, whether automated for report generation or initiated by users, should be streamlined for optimal results.

To enhance query efficiency:

Align with Business Requirements: Understand the specific business needs to extract only necessary data, preventing unnecessary strain on the database. This ensures that queries focus on essential information.

Avoid SELECT and SELECT DISTINCT:* Refrain from using broad selections like SELECT* or SELECT DISTINCT, as these compel the database to process unnecessary data. Optimize queries by specifying particular fields, reducing processing time and resource usage.

Prefer INNER JOIN over Subqueries: Opt for INNER JOIN over subqueries to enhance performance. Subqueries can necessitate sifting through a large result set, whereas JOINing tables directly is often more efficient.

Moreover, leveraging pre-aggregated queries enhances read functionality. This involves assembling data in tables to measure specific metrics, eliminating the need to recapture data with each query and thereby improving overall database performance.

Caching

Caching can be a helpful tool for optimizing your database performance. It stores tables and queries in short-term memory, allowing you to access them quickly without having to repeatedly query the database itself. For example, if you often request annual sales reports, you can save them in the cache and retrieve them directly from memory instead of asking the database to generate them every time. This can save resources and improve performance.

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