Database Internals & Storage Engines Certification

The Database Internals & Storage Engines Certification is a free advanced-level, 25-minute skill test from Science of Apps. It tests database internals and storage engines — disk-oriented architecture, pages and slotted page layouts, buffer pool management and replacement policies, B+ trees and their operations, LSM trees with memtables, SSTables, compaction and Bloom filters, hash indexes, write-ahead logging and ARIES-style recovery, checkpoints, concurrency control with two-phase locking and MVCC, isolation levels and anomalies, query processing with iterators, join algorithms such as nested loop, hash and sort-merge joins, cost-based query optimisation and cardinality estimation, column stores and compression, and replication and partitioning — written to CMU's database course, Designing Data-Intensive Applications, PostgreSQL and SQLite documentation for 2026 and 2027. Score 70% or more on its 25 questions to earn a verifiable Database Internals & Storage Engines certificate (SOA-DISE). Every question is based on published standards and research — including CMU 15-445/645 Database Systems course materials (Carnegie Mellon University Database Group), PostgreSQL documentation (PostgreSQL Global Development Group), Designing Data-Intensive Applications (Martin Kleppmann (O'Reilly)) — and each answer is explained with its source.

Science of Apps offers a free Database Internals & Storage Engines Certification, written for 2026 and 2027. It tests storage and buffering, indexes, transactions and recovery, query processing and optimisation and distribution with 25 original scenario questions in all, each naming its published source; you get an instant score and a verifiable certificate with a credential ID you can add to LinkedIn.

Read the five skill areas on this page, then take the 25-minute test online — no fee, course or sign-up. You see every answer explained when you finish. Score 70% or more and you get a Database Internals & Storage Engines certificate straight away, on screen, as a PDF and by email, with a credential ID anyone can verify.

Yes. The questions are original scenarios written by Science of Apps, and each one is based on a public source you can read: CMU 15-445/645 Database Systems course materials (Carnegie Mellon University Database Group); PostgreSQL documentation (PostgreSQL Global Development Group); Designing Data-Intensive Applications (Martin Kleppmann (O'Reilly)); SQLite architecture and file format documentation (SQLite). The source is shown under each question and linked in the answer review. Science of Apps doesn't copy questions from other tests.

Five skill areas with five questions each, drawn from a bank of 10 per area so a retake brings new questions: Storage and Buffering (Pages and files, Buffer pool and Data layout); Indexes (B+ trees, LSM trees and Hash and other indexes); Transactions and Recovery (ACID and logging, Recovery and Concurrency control); Query Processing (Execution models, Join algorithms and Sorting and aggregation); Optimisation and Distribution (Query optimisation, Statistics and estimation and Replication and partitioning). Every question is an original scenario written to the 2026–2027 standard, with the published source named under it.

Database or storage engineer, Backend engineer optimising data systems, Data platform or infrastructure engineer, Performance engineer and Computer science student. It suits students at leading universities, career switchers and experienced professionals who want quick, verifiable proof of Database Internals & Storage Engines knowledge in 2026 and 2027.

CS and AI students at MIT, Stanford, CMU, Berkeley, IITs, Tsinghua and ETH are hired on depth beyond tool use: model internals, systems and hardware. Passing earns a founder-signed Science of Apps certificate with a credential ID and QR code that recruiters can verify.

B+ trees update pages in place and suit read-heavy workloads with predictable lookups. LSM trees buffer writes in memory and flush sorted files that are later compacted, favouring write-heavy workloads at some cost to reads.

Changes are recorded in a durable log before data pages are written, so after a crash the database can redo committed work and undo incomplete transactions.

Yes. The test is online, in English and free everywhere — people take it from India, the US, the UK, Europe, Africa, Latin America and Asia-Pacific. Your certificate is dated with your own local date and can be verified from anywhere at scienceofapps.com/certification/verify/.

25 questions — 5 from each of 5 skill areas — with a 25-minute limit. You need 70% (18 of 25) to pass and 90% for distinction.

We rate it Advanced: assumes years in the role or deep specialist knowledge. It has 25 scenario questions — 5 from each of 5 skill areas — and a 25-minute limit. You need 70% (18 of 25) to pass and 90% for distinction.

Nothing. There is no fee to take a test, to receive the certificate, to have it emailed or to verify it, and no sign-up.

On our server, not in your browser. The answers never reach the page until you submit, so a certificate can only be earned by passing. Each certificate gets a unique credential ID stored by Science of Apps.

You see your score for each area and every question with the correct answer and why, with the published source behind it. You can retake after 30 minutes, and the retake draws questions you haven't seen yet.

No. Every certificate is dated, so it always shows when you passed. Retake a test any time for a newer date or a higher score.

Yes. After you pass, Add to LinkedIn opens the Licenses & certifications form with the certificate name, Science of Apps as the issuer, the issue date, your credential ID and the verification link filled in. You can also download it as a PDF or PNG, and it's emailed to you as a PDF.

Every certificate has a credential ID and a QR code. Scanning it, or entering the ID at scienceofapps.com/certification/verify/, shows the holder's name, the certification, the score and the issue date from our records.

No. They are Science of Apps' own assessments of applied skill. They aren't issued by a university or standards body, and they work best alongside a portfolio that shows the skills in real work.