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Vignesh Kumar ADatabase Engineer · Chennai, India

A write-ahead log of what I learn.

I'm Vignesh. I work on database internals at Zoho. Every post here is a record: written down plainly, corrected in the open, never quietly rewritten.

Currently: sharding, distributed query execution and two-phase commit, in C.

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Hi, I'm Vignesh. Start here

I'm a database engineer at Zoho, working on database internals. Why I write here in public, and how to use the site.

· 3 min read

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  • PostgreSQL internals, explained simply

    series · active

    One mechanism per post, in the order a change flows through the server. Analogy first, then the real thing, then the gotchas.

    1 of 5 published · #postgresql #databases

    last active

Also reading Consensus on Transaction Commit, Designing Data-Intensive Applications and The Rust Programming Language. Bookshelf →

Latest all →

StreamsTech4Meta1

  • How PostgreSQL tells every connection its cache is stale

    explainer

    Each PostgreSQL connection caches the catalog for itself. How a change is announced to all of them at commit through a shared ring, and what happens to a connection that falls behind.

    PostgreSQL internals, explained simply · part 5 · 19 min · #postgresql #databases #performance

  • Full-page writes and torn pages

    note · evergreen

    Why the first change to a page after a checkpoint carries the whole 8 KB page in WAL.

    #postgresql #databases

  • Lazy transaction id assignment

    note · seedling

    A transaction does not get an xid at BEGIN; it gets one the first time it writes.

    #postgresql

  • pd_lsn vs record LSN

    note · budding

    Two LSNs that are easy to mix up, and the rule recovery uses to compare them.

    #postgresql

Projects all →

  • Decentralized P2P Network

    2025project · paused

    A peer-to-peer messaging network in Rust on libp2p: messages arrive in under 50 ms across 100+ nodes, with Ed25519 peer identity and Noise-protocol encryption.

    code not public yet · rust · libp2p · ed25519 · noise

  • Hybrid Storage Engine

    2026project · paused

    A key-value engine in C that keeps values in an append-only log and keys in a B-tree, so rewriting a large value does not churn the index around it.

    code not public yet · c

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