StoreOptions

The options of one open store, which may differ at every open. Every option has a safe default, so StoreOptions() opens a store that works on any heap; the values below bound what a store does, never how much of the JVM's heap it needs, which the engine derives from the heap it runs on. The options fixed when a store is created are CreationOptions.

Options are values: two instances with the same settings are equal, and copy derives a variant, such as StoreOptions().copy(compression = false).

• encoderBudgetBytes: pending bytes an insert keeps before it writes fragments early; null for the default. It only steers how new inserts are split. Opening a store fails with IllegalArgumentException when it is below twice the store's CreationOptions.fragmentBytes.

• maxDepth, maxDocumentBytes, maxStringBytes: limits of SPEC.md §1.3; a document over one of them is rejected with RejectReason.LIMIT_EXCEEDED.

• ioParallelism: threads for the suspending operations of JsonStore.

• durability: when acknowledged writes are synced to disk.

• compression: compress fragment payloads. Each payload records how it was stored, so a store written with compression reads back with it off and the other way round; the option only chooses what new writes do.

• mmapReads: read sealed segment files through memory mappings instead of positional reads. Saves a copy per block read and leaves the pages to the OS. Off by default: on Windows a mapped file can't be deleted, so a compaction that retires a mapped segment waits for its readers, and a store that maps far more than the machine's memory pages harder than it reads. Try it on read-heavy stores whose segments fit in memory.