Experimental Features

Preview engine capabilities and APIs that are not yet part of BoutiqueDB’s stable surface.

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Experimental features

The Turso engine exposes several opt-in features. BoutiqueDB surfaces them through TursoOpenOptions and probes them through db.capabilities.

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Official feature tokens

The engine recognizes the following tokens in the experimental_features comma-separated string:

• views — materialized views and incremental view maintenance (IVM).
• custom_types — CREATE TYPE and CREATE DOMAIN for STRICT tables.
• encryption — at-rest encryption (requires cipher and key).
• index_method — custom index methods such as USING fts and USING vector.
• autovacuum — auto-vacuum support.
• vacuum — VACUUM semantics beyond VACUUM INTO.
• attach — ATTACH DATABASE support.
• generated_columns — GENERATED ALWAYS AS virtual columns.
• without_rowid — WITHOUT ROWID tables.
• multiprocess_wal — cross-process WAL coordination via .tshm sidecar.
• mvcc_passive_checkpoint — MVCC passive checkpoint behavior.

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Enabling in BoutiqueDB

let db = try BoutiqueDB(
  url: url,
  openOptions: TursoOpenOptions(
    experimentalFeatures: [.indexMethod, .views, .generatedColumns]
  )
)

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Capability probes

Not every engine build includes every feature. db.capabilities checks support at runtime:

if db.capabilities.ftsIndex {
  // safe to create FTS indexes
}
if db.capabilities.vectorIndex {
  // safe to create vector indexes
}
if db.capabilities.materializedViews {
  // safe to create materialized views
}

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Stability notes

These features are experimental in the upstream engine:

• MVCC is under active development; indexes are not supported in MVCC mode.
• Materialized views (IVM) have limited SQL support and may reject complex source queries.
• Encryption at rest is not yet recommended for critical data without independent backups.
• Multi-process WAL requires coordination through the .tshm sidecar and is only supported on 64-bit Unix and Windows.

Warning: Experimental features may change behavior, produce incorrect results, or panic in edge cases. Enable them only when you need them and test thoroughly.

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Default preset

TursoOpenOptions.tursoEnhanced enables views, index_method, generated_columns, vacuum, and without_rowid. This is the recommended starting point for product apps.

For usage examples, see Turso features in Apple apps.