Using DataVoContext

DataVoContext is the main embedded API. It owns the engine instance, the default session, and the storage configuration for the process. Most applications start with one context per embedded database lifecycle.

Create a context with explicit configuration. During development, in-memory mode keeps setup simple.

using DataVo.Core;
using DataVo.Core.Contracts.Results;
using DataVo.Core.StorageEngine.Config;

using var db = new DataVoContext(new DataVoConfig
{
    StorageMode = StorageMode.InMemory
});

Every statement runs in a logical session. If you call Execute(sql) without a session ID, DataVo uses the context's default session.

db.Execute("CREATE DATABASE App");
db.Execute("USE App");
db.Execute("CREATE TABLE Events (Id INT PRIMARY KEY, Name VARCHAR(80))");
db.Execute("INSERT INTO Events (Id, Name) VALUES (1, 'started')");

Read results through QueryResult. The general SQL path returns dictionaries keyed by column name.

QueryResult result = db.Execute("""
SELECT Id, Name
FROM Events
ORDER BY Id ASC;
""")[0];

foreach (var row in result.Data)
{
    int id = Convert.ToInt32(row["Id"]);
    string name = Convert.ToString(row["Name"]) ?? "";
    Console.WriteLine($"{id}: {name}");
}

Use explicit sessions when you need independent transaction scopes. A transaction started in one session does not belong to another session.

Guid writerSession = Guid.NewGuid();

db.Execute("USE App", writerSession);
db.Execute("BEGIN TRANSACTION", writerSession);
db.Execute("INSERT INTO Events (Id, Name) VALUES (2, 'queued')", writerSession);
db.Execute("COMMIT", writerSession);

Rollback uses the same session-bound pattern.

Guid rollbackSession = Guid.NewGuid();

db.Execute("USE App", rollbackSession);
db.Execute("BEGIN TRANSACTION", rollbackSession);
db.Execute("INSERT INTO Events (Id, Name) VALUES (3, 'temporary')", rollbackSession);
db.Execute("ROLLBACK", rollbackSession);

For persistent storage, the context configuration is the only part that changes. Disk mode is the simpler file-backed backend.

using var diskDb = new DataVoContext(new DataVoConfig
{
    StorageMode = StorageMode.Disk,
    DiskStoragePath = "./datavo_data",
    WalEnabled = true,
    SyncDiskWrites = true
});

LSM mode is the high-throughput backend. Keep LsmStrictFsync = true for durability-sensitive tests.

using var lsmDb = new DataVoContext(new DataVoConfig
{
    StorageMode = StorageMode.Lsm,
    DiskStoragePath = "./datavo_lsm_data",
    LsmStrictFsync = true
});

DataVoContext API Summary

DataVoContext supports Execute(string query) against the default session and Execute(string query, Guid sessionId) against an explicit session, session-bound transactions (BEGIN TRANSACTION, COMMIT, ROLLBACK), dictionary row results in QueryResult.Data, and persistent Disk and Lsm storage (with WAL and durability settings). The public examples use synchronous Execute; an async general SQL API is planned.