mq-db 0.1.13

Markdown-specialized embedded database with interval-indexed block storage and hierarchical query support
Documentation
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          <a class="text-ink-dim hover:text-accent transition-colors" href="#anatomy">Anatomy</a>
          <a class="text-ink-dim hover:text-accent transition-colors" href="#why-mqdb">Why mq-db</a>
          <a class="text-ink-dim hover:text-accent transition-colors" href="#query">Query</a>
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            >crates.io</a
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          <h1 class="text-4xl sm:text-5xl lg:text-6xl font-headline font-semibold tracking-tight leading-[1.08] mb-6 max-w-3xl fade-up">
            Your Markdown<br />
            is already <em class="not-italic text-accent">a database.</em>
          </h1>
          <p class="text-lg text-ink-dim max-w-2xl mb-10 leading-relaxed fade-up">
            mq-db parses Markdown into a flat block list with an interval
            index (Nested Set / Pre-Post Order), turning heading hierarchy
            into O(1) integer comparisons. Query it with
            <span class="text-ink font-medium">SQL</span> or
            <a href="https://github.com/harehare/mq" target="_blank" class="text-accent hover:underline">mq</a>,
            persist it to a compact custom page-file format — no SQLite
            dependency.
          </p>
          <div class="flex flex-wrap gap-3 mb-16 fade-up">
            <a
              href="#install"
              class="px-6 py-3 bg-accent text-paper font-semibold rounded-lg font-body text-sm hover:bg-accent-hover transition-colors"
              >install mq-db &rarr;</a
            >
            <a
              href="https://github.com/harehare/mq-db"
              target="_blank"
              class="px-6 py-3 border border-ink/20 text-ink font-body text-sm rounded-lg hover:border-accent hover:text-accent transition-colors"
              >view source</a
            >
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          <div id="anatomy" class="scroll-mt-24 fade-up">
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                  <span class="h-2.5 w-2.5 rounded-full bg-ink-dim/30"></span>
                </div>
                <span class="hidden sm:inline">sql&gt; every block nested under a heading, in one comparison</span>
                <span class="text-mark font-mono">under()</span>
              </div>
              <pre class="p-5 text-xs md:text-sm font-mono leading-relaxed overflow-x-auto"><span class="text-ink-dim italic">-- all text/code nested under the "Architecture" heading</span>
<span class="text-accent">SELECT</span> b.block_type, b.content
<span class="text-accent">FROM</span> blocks b
<span class="text-accent">WHERE</span> under(b.pre, b.post,
  (<span class="text-accent">SELECT</span> pre  <span class="text-accent">FROM</span> blocks <span class="text-accent">WHERE</span> block_type = <span class="text-mark">'heading'</span> <span class="text-accent">AND</span> content = <span class="text-mark">'Architecture'</span>),
  (<span class="text-accent">SELECT</span> post <span class="text-accent">FROM</span> blocks <span class="text-accent">WHERE</span> block_type = <span class="text-mark">'heading'</span> <span class="text-accent">AND</span> content = <span class="text-mark">'Architecture'</span>))
  <span class="text-accent">AND</span> b.block_type <span class="text-accent">IN</span> (<span class="text-mark">'paragraph'</span>, <span class="text-mark">'code'</span>)
<span class="text-accent">ORDER BY</span> b.pre;</pre>
            </div>
            <p class="text-xs text-ink-dim mt-3">
              Every block gets a <span class="text-ink font-medium">pre</span>/<span class="text-ink font-medium">post</span> pair at index time — "is X inside Y?" becomes one integer range comparison, not a tree walk.
            </p>
          </div>
        </div>
      </section>

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          <h2 class="text-3xl font-headline font-semibold mb-14 tracking-tight text-ink">Why mq-db</h2>
          <div class="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-4 gap-x-8 gap-y-12">
            <div>
              <h3 class="font-headline font-semibold text-lg text-ink mb-2">No tree walk</h3>
              <p class="text-sm text-ink-dim leading-relaxed">
                Nested Set (pre/post) encoding assigned at index time turns
                "is X inside Y?" into a single interval comparison —
                <code class="text-accent">under(pre, post, anc_pre, anc_post)</code>.
              </p>
            </div>
            <div>
              <h3 class="font-headline font-semibold text-lg text-ink mb-2">Three index layers</h3>
              <p class="text-sm text-ink-dim leading-relaxed">
                A <code class="text-accent">BitmapIndex</code> on block type,
                a <code class="text-accent">BTreeIndex</code> on pre/post, and
                a <code class="text-accent">HashIndex</code> on content/lang/depth
                push SQL predicates down before a block is materialized.
              </p>
            </div>
            <div>
              <h3 class="font-headline font-semibold text-lg text-ink mb-2">Two query engines</h3>
              <p class="text-sm text-ink-dim leading-relaxed">
                A custom sqlparser-based SQL evaluator, and mq via mq-lang —
                run either against the same block storage. No SQLite
                dependency.
              </p>
            </div>
            <div>
              <h3 class="font-headline font-semibold text-lg text-ink mb-2">Zone-map pruning</h3>
              <p class="text-sm text-ink-dim leading-relaxed">
                Per-document statistics skip irrelevant files before a
                single block is scanned, ahead of the index layers.
              </p>
            </div>
          </div>
        </div>
      </section>

      <!-- Stats -->
      <section class="py-16 border-t border-paper-deep bg-paper-alt/60">
        <div class="max-w-[1200px] mx-auto px-6">
          <div class="grid grid-cols-2 lg:grid-cols-4 gap-8">
            <div>
              <p class="text-4xl sm:text-5xl font-headline font-semibold text-ink tracking-tight">O(1)</p>
              <p class="text-xs text-ink-dim uppercase tracking-widest mt-2">ancestor / descendant checks</p>
            </div>
            <div>
              <p class="text-4xl sm:text-5xl font-headline font-semibold text-ink tracking-tight">3</p>
              <p class="text-xs text-ink-dim uppercase tracking-widest mt-2">index layers &mdash; bitmap &middot; btree &middot; hash</p>
            </div>
            <div>
              <p class="text-4xl sm:text-5xl font-headline font-semibold text-ink tracking-tight">8&nbsp;KB</p>
              <p class="text-xs text-ink-dim uppercase tracking-widest mt-2">fixed pages, checksummed</p>
            </div>
            <div>
              <p class="text-4xl sm:text-5xl font-headline font-semibold text-ink tracking-tight">0</p>
              <p class="text-xs text-ink-dim uppercase tracking-widest mt-2">external db dependencies</p>
            </div>
          </div>
        </div>
      </section>

      <!-- Query examples -->
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        <div class="max-w-[1200px] mx-auto px-6">
          <h2 class="text-3xl font-headline font-semibold mb-4 tracking-tight text-ink">SQL, joins included</h2>
          <p class="text-ink-dim max-w-2xl mb-14 leading-relaxed">
            <code class="text-accent">documents</code> and <code class="text-accent">blocks</code> are
            plain virtual tables — join them like any relational schema, plus
            self-joins over the interval index for structural checks.
          </p>
          <div class="grid grid-cols-1 md:grid-cols-2 gap-x-6 gap-y-10">
            <div>
              <div class="border border-paper-deep rounded-xl bg-paper-alt overflow-hidden">
                <div class="flex items-center justify-between px-4 py-2.5 border-b border-paper-deep text-xs font-body text-ink-dim">
                  <span>documents &#8904; blocks</span>
                  <span class="text-mark font-mono">JOIN</span>
                </div>
                <pre class="p-5 text-xs md:text-sm font-mono leading-relaxed overflow-x-auto"><span class="text-ink-dim italic">-- documents that contain Python code</span>
<span class="text-accent">SELECT DISTINCT</span> d.path
<span class="text-accent">FROM</span> documents d
<span class="text-accent">JOIN</span> blocks b <span class="text-accent">ON</span> b.document_id = d.id
<span class="text-accent">WHERE</span> b.block_type = <span class="text-mark">'code'</span> <span class="text-accent">AND</span> b.lang = <span class="text-mark">'python'</span>;</pre>
              </div>
              <p class="text-xs italic text-ink-dim mt-3">fig. 1 — a plain relational join across documents and blocks.</p>
            </div>
            <div>
              <div class="border border-paper-deep rounded-xl bg-paper-alt overflow-hidden">
                <div class="flex items-center justify-between px-4 py-2.5 border-b border-paper-deep text-xs font-body text-ink-dim">
                  <span>self-join over pre/post</span>
                  <span class="text-mark font-mono">JOIN &times;2</span>
                </div>
                <pre class="p-5 text-xs md:text-sm font-mono leading-relaxed overflow-x-auto"><span class="text-ink-dim italic">-- H2 headings immediately followed by a list</span>
<span class="text-accent">SELECT</span> d.path, h.content <span class="text-accent">AS</span> heading
<span class="text-accent">FROM</span> blocks h
<span class="text-accent">JOIN</span> blocks nxt <span class="text-accent">ON</span> nxt.document_id = h.document_id
                 <span class="text-accent">AND</span> nxt.pre = h.pre + 1
<span class="text-accent">JOIN</span> documents d <span class="text-accent">ON</span> d.id = h.document_id
<span class="text-accent">WHERE</span> h.block_type = <span class="text-mark">'heading'</span> <span class="text-accent">AND</span> h.depth = 2
  <span class="text-accent">AND</span> nxt.block_type = <span class="text-mark">'list'</span>;</pre>
              </div>
              <p class="text-xs italic text-ink-dim mt-3">fig. 2 — a structural self-join, one row apart in pre-order.</p>
            </div>
            <div>
              <div class="border border-paper-deep rounded-xl bg-paper-alt overflow-hidden">
                <div class="flex items-center justify-between px-4 py-2.5 border-b border-paper-deep text-xs font-body text-ink-dim">
                  <span>mq() scalar function</span>
                  <span class="text-mark font-mono">inline mq</span>
                </div>
                <pre class="p-5 text-xs md:text-sm font-mono leading-relaxed overflow-x-auto"><span class="text-ink-dim italic">-- run an mq program against Markdown content, in SQL</span>
<span class="text-accent">SELECT</span> mq(<span class="text-mark">'.h1 | to_text'</span>, content) <span class="text-accent">AS</span> title
<span class="text-accent">FROM</span> blocks
<span class="text-accent">WHERE</span> block_type = <span class="text-mark">'code'</span> <span class="text-accent">AND</span> lang = <span class="text-mark">'markdown'</span>;</pre>
              </div>
              <p class="text-xs italic text-ink-dim mt-3">fig. 3 — mq embedded as a scalar function inside a SQL projection.</p>
            </div>
            <div>
              <div class="border border-paper-deep rounded-xl bg-paper-alt overflow-hidden">
                <div class="flex items-center justify-between px-4 py-2.5 border-b border-paper-deep text-xs font-body text-ink-dim">
                  <span>CASE + aggregates</span>
                  <span class="text-mark font-mono">GROUP BY</span>
                </div>
                <pre class="p-5 text-xs md:text-sm font-mono leading-relaxed overflow-x-auto"><span class="text-ink-dim italic">-- bucket headings by depth, summarize per bucket</span>
<span class="text-accent">SELECT</span>
  <span class="text-accent">CASE WHEN</span> depth &lt;= 1 <span class="text-accent">THEN</span> <span class="text-mark">'top-level'</span> <span class="text-accent">ELSE</span> <span class="text-mark">'nested'</span> <span class="text-accent">END AS</span> bucket,
  count(*),
  group_concat(initcap(trim(content)), <span class="text-mark">', '</span>) <span class="text-accent">AS</span> headings
<span class="text-accent">FROM</span> blocks
<span class="text-accent">WHERE</span> block_type = <span class="text-mark">'heading'</span>
<span class="text-accent">GROUP BY</span> <span class="text-accent">CASE WHEN</span> depth &lt;= 1 <span class="text-accent">THEN</span> <span class="text-mark">'top-level'</span> <span class="text-accent">ELSE</span> <span class="text-mark">'nested'</span> <span class="text-accent">END</span>;</pre>
              </div>
              <p class="text-xs italic text-ink-dim mt-3">fig. 4 — CASE expressions and aggregates over heading depth.</p>
            </div>
          </div>
        </div>
      </section>

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            <span class="font-mono text-xs text-ink-dim">9 entries</span>
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                <span class="font-mono text-accent text-xs w-5 shrink-0">01</span>
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              <p class="text-xs text-ink-dim leading-relaxed pl-8">Every Markdown element becomes a typed Block with row-polymorphic properties.</p>
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                <span class="font-mono text-accent text-xs w-5 shrink-0">02</span>
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              <p class="text-xs text-ink-dim leading-relaxed pl-8">Interval index (pre/post) makes ancestor/descendant checks a single comparison.</p>
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                <span class="font-mono text-accent text-xs w-5 shrink-0">03</span>
                <h4 class="font-headline font-semibold text-ink">Three-layer indexes</h4>
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              <p class="text-xs text-ink-dim leading-relaxed pl-8">Bitmap, BTree, and Hash indexes for fast SQL predicate pushdown.</p>
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                <span class="font-mono text-accent text-xs w-5 shrink-0">04</span>
                <h4 class="font-headline font-semibold text-ink">Zone maps</h4>
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              <p class="text-xs text-ink-dim leading-relaxed pl-8">Per-document statistics skip irrelevant files before scanning any blocks.</p>
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              <div class="flex items-baseline gap-3 mb-1.5">
                <span class="font-mono text-accent text-xs w-5 shrink-0">05</span>
                <h4 class="font-headline font-semibold text-ink">Dual query engines</h4>
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              <p class="text-xs text-ink-dim leading-relaxed pl-8">SQL via a custom sqlparser-based evaluator, and mq via mq-lang.</p>
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            <div class="px-5 py-4">
              <div class="flex items-baseline gap-3 mb-1.5">
                <span class="font-mono text-accent text-xs w-5 shrink-0">06</span>
                <h4 class="font-headline font-semibold text-ink">DDL support</h4>
              </div>
              <p class="text-xs text-ink-dim leading-relaxed pl-8"><code class="text-accent">CREATE TABLE</code>, <code class="text-accent">INSERT INTO</code>, <code class="text-accent">DROP TABLE</code> for in-memory custom tables.</p>
            </div>
            <div class="px-5 py-4">
              <div class="flex items-baseline gap-3 mb-1.5">
                <span class="font-mono text-accent text-xs w-5 shrink-0">07</span>
                <h4 class="font-headline font-semibold text-ink">Function library</h4>
              </div>
              <p class="text-xs text-ink-dim leading-relaxed pl-8">String, numeric, null-handling, CASE, and aggregate functions comparable to a general-purpose RDBMS.</p>
            </div>
            <div class="px-5 py-4">
              <div class="flex items-baseline gap-3 mb-1.5">
                <span class="font-mono text-accent text-xs w-5 shrink-0">08</span>
                <h4 class="font-headline font-semibold text-ink">Custom page storage</h4>
              </div>
              <p class="text-xs text-ink-dim leading-relaxed pl-8">8 KB fixed pages, checksums, atomic writes to a single-file format.</p>
            </div>
            <div class="px-5 py-4">
              <div class="flex items-baseline gap-3 mb-1.5">
                <span class="font-mono text-accent text-xs w-5 shrink-0">09</span>
                <h4 class="font-headline font-semibold text-ink">CLI + REPL + TUI</h4>
              </div>
              <p class="text-xs text-ink-dim leading-relaxed pl-8">Full terminal experience, plus an HTTP server for SQL and mq over JSON.</p>
            </div>
          </div>
        </div>
      </section>

      <!-- Install -->
      <section id="install" class="scroll-mt-24 py-24 border-t border-paper-deep">
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          <h2 class="text-3xl font-headline font-semibold mb-10 tracking-tight text-ink text-center">Install</h2>
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                <p class="text-ink-dim italic"># downloads, verifies (SHA256), and installs to ~/.local/bin</p>
                <p class="text-ink">curl -fsSL https://raw.githubusercontent.com/harehare/mq-db/main/bin/install.sh | bash</p>
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                <p class="text-ink">cargo install --path .</p>
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          <p class="mt-8 text-center text-sm font-mono text-ink-dim">
            mq-db index docs/ --recursive <span class="text-ink-dim">&&</span>
            <span class="text-accent">mq-db sql "SELECT block_type, count(*) FROM blocks GROUP BY block_type"</span>
          </p>
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