MySQL vs PostgreSQL vs SQLite

MySQL, PostgreSQL, and SQLite all store relational data, but they put the database in different places. Think of the choice as selecting a workshop: MySQL and PostgreSQL provide a staffed server room, while SQLite keeps the tools in a file beside the application.

No database engine wins across every workload. Choose from deployment, write concurrency, data rules, provider support, and recovery needs. Those criteria produce a decision that can be tested instead of a personal verdict.

Quick Comparison

MySQL and PostgreSQL coordinate clients through a server process, while SQLite reads and writes a database file through the application.

Database	Deployment	Starting Fit
MySQL	Database server	Conventional hosted apps
PostgreSQL	Database server	Detailed relational models
SQLite	Application file	Local or embedded data

That workshop layout often matters more than a long feature list.

Choose by Deployment Shape

Begin by drawing where the application and database run. A desktop tool that owns one local file has different needs from a hosted service with several application instances and frequent writes.

• Choose a client-server engine when many processes or machines must coordinate writes.
• Consider SQLite when the data belongs to one application or device and writes can queue.
• Check which engines the framework, managed provider, deployment platform, and backup tooling support directly.
• Confirm who will patch, monitor, back up, and restore the database.

SQLite's official guidance states that it permits many simultaneous readers and one writer at a time per database file. It recommends a client-server database when many clients need to send SQL over a network or many writers cannot take turns.

When MySQL Fits

MySQL fits conventional web applications when the surrounding stack already targets MySQL. PHP drivers, managed services, hosting panels, migration tools, and operational experience can make that support path shorter.

Use MySQL as the starting candidate when:

• The provider documents MySQL as a supported service.
• The application and dependencies test against the selected MySQL release.
• The workload is ordinary relational CRUD with client-server concurrency.
• The team has a verified MySQL backup and restore procedure.

Do not carry old PHP habits into a new schema. Use InnoDB, parameterized queries, constraints, tested migrations, and current drivers. The database can be familiar without the application repeating obsolete examples.

When PostgreSQL Fits

PostgreSQL fits when detailed constraints, specialized types, extensions, indexing options, or database-side querying are central to the product. The PostgreSQL project describes it as an object-relational database that extends SQL for complex data workloads.

Use PostgreSQL as the starting candidate when:

• The schema needs detailed integrity rules and expressive data types.
• Reporting, window functions, indexing, or full-text search will do substantial work.
• An extension such as PostGIS is a documented requirement.
• The team and provider support PostgreSQL operations and upgrades.

A larger feature surface is useful only when the application needs it and the team can operate it. PostgreSQL does not repair a vague schema or an untested restore plan.

When SQLite Fits

SQLite fits local applications, embedded devices, command-line tools, test suites, application file formats, and some low-write websites. It removes the separate server from the workshop, which reduces deployment and administration.

Use SQLite as the starting candidate when:

• One application or device owns the database file.
• Write transactions are brief and can take turns.
• Simple distribution and local access matter more than network coordination.
• The backup plan can safely copy or snapshot the database.

SQLite is a serious database whose main boundary is topology. A file on one device is a strong design for local data and a weak substitute for a shared database server across several machines.

Compare Portable SQL

Basic selections, filters, grouping, and ordering often transfer across all three engines. This query returns the two customers with the highest paid-order totals:

SELECT customer_id, SUM(total_cents) AS paid_total
FROM orders
WHERE status = 'paid'
GROUP BY customer_id
ORDER BY paid_total DESC
LIMIT 2;

For fixtures where customer 7 has paid orders of 1200 and 800 cents, and customer 12 has one paid order of 1500 cents, the expected rows are customer 7 with 2000 followed by customer 12 with 1500.

Portable queries do not make a whole schema portable. Generated identifiers, upserts, JSON expressions, date arithmetic, collations, null ordering, full-text search, and administrative commands need engine-specific tests.

Compare JSON and Search

All three engines have JSON functions, but they store and index JSON differently. PostgreSQL offers json and jsonb, including indexes for common jsonb operations. MySQL provides a native JSON type and supports indexing extracted values through generated or compatible virtual columns.

SQLite stores ordinary JSON as text and also supports its own internal JSONB format. SQLite's documentation warns that its JSONB is not binary-compatible with PostgreSQL JSONB and does not make PostgreSQL's lookup-performance claims. The shared name is not a portability guarantee.

Search capabilities follow the same product-specific pattern. PostgreSQL has full-text search types, dictionaries, ranking, and indexes. MySQL supports FULLTEXT indexes and search modes for supported storage engines and text columns. SQLite provides FTS modules for search close to local file-based data.

Choose by testing the application's real search query. Product search with typo tolerance, language rules, facets, and analytics may still need a dedicated search service regardless of the primary relational database.

Common Pitfalls and Debugging

Choosing from a Generic Benchmark

A local SQLite read, a tuned PostgreSQL analytical query, and a MySQL web workload measure different systems. Reproduce the application's data size, indexes, query mix, write concurrency, and network layout. Record latency and resource use under that workload.

Putting SQLite on a Network Filesystem

A shared file does not become a client-server database. File locking and network behavior can make this design unsafe or fragile. Keep SQLite close to the application that owns the file, or move concurrent network clients to MySQL or PostgreSQL.

Assuming Portable SQL Means Portable Schemas

A simple SELECT can work everywhere while migrations fail on identity columns, types, constraints, or functions. Run the complete migration sequence and integration suite against every supported engine, then compare results with known fixtures.

How to Decide

The table maps common requirements to a starting point that still needs workload and recovery testing.

Requirement	Starting Point
Hosted PHP stack	MySQL
Detailed data rules	PostgreSQL
Device-local storage	SQLite
Concurrent network writes	MySQL or PostgreSQL
PostGIS requirement	PostgreSQL
Single-file app state	SQLite

Validate the starting point against provider support, application queries, write concurrency, migration tooling, and restore tests. A different engine wins whenever those criteria change.

Frequently Asked Questions

Which database is best for a small PHP app?

SQLite fits a single-server or local PHP app with light write concurrency and simple file-based deployment. MySQL fits conventional PHP stacks on supported hosting. PostgreSQL fits when richer constraints, types, extensions, or reporting justify a client-server database. The hosting and recovery plan decide the starting point.

Can SQLite handle concurrent users?

SQLite can handle concurrent users and allows many simultaneous readers, but only one writer can hold the write lock at a time for each database file. Brief write transactions can usually queue successfully. Sustained concurrent writes or several application servers usually point toward MySQL or PostgreSQL.

Is PostgreSQL always better than MySQL?

The better engine depends on the workload. PostgreSQL offers a broad set of types, constraints, indexes, extensions, and database-side features. MySQL may be the better operational fit when the application, provider, and team already support it. Compare requirements and recovery procedures instead of counting features.

Can an application switch databases later?

An application can switch databases later, but the move needs planned migration work. Generated keys, data types, JSON behavior, full-text search, collations, date functions, upserts, and administrative tools differ. Test every migration and important query against the destination, then rehearse export, import, verification, and rollback.

What to Read Next

Use the SQL database guides for engine-specific details. Compare a different data model in SQL vs NoSQL, or continue with SQL schema design basics before creating production tables.