OptimisticTransactionDB

static Status Open(
  const Options& options,
  const std::string& dbname,
  OptimisticTransactionDB** dbptr
);

static Status Open(
  const DBOptions& db_options,
  const std::string& dbname,
  const std::vector<ColumnFamilyDescriptor>& column_families,
  std::vector<ColumnFamilyHandle*>* handles,
  OptimisticTransactionDB** dbptr
);

static Status Open(
  const DBOptions& db_options,
  const OptimisticTransactionDBOptions& occ_options,
  const std::string& dbname,
  const std::vector<ColumnFamilyDescriptor>& column_families,
  std::vector<ColumnFamilyHandle*>* handles,
  OptimisticTransactionDB** dbptr
);

virtual Transaction* BeginTransaction(
  const WriteOptions& write_options,
  const OptimisticTransactionOptions& txn_options =
      OptimisticTransactionOptions(),
  Transaction* old_txn = nullptr
);

struct OptimisticTransactionOptions {
  bool set_snapshot = false;
  const Comparator* cmp = BytewiseComparator();
};

struct OptimisticTransactionDBOptions {
  OccValidationPolicy validate_policy = OccValidationPolicy::kValidateParallel;
  uint32_t occ_lock_buckets = (1 << 20);
  std::shared_ptr<OccLockBuckets> shared_lock_buckets;
};

#include "rocksdb/utilities/optimistic_transaction_db.h"

using namespace ROCKSDB_NAMESPACE;

// Open OptimisticTransactionDB
Options options;
options.create_if_missing = true;
OptimisticTransactionDB* txn_db;

Status s = OptimisticTransactionDB::Open(options, "/tmp/testdb", &txn_db);
assert(s.ok());

// Start a transaction
WriteOptions write_options;
OptimisticTransactionOptions txn_options;
Transaction* txn = txn_db->BeginTransaction(write_options, txn_options);

// Write within transaction
s = txn->Put("key1", "value1");
assert(s.ok());

// Commit - will fail if there were conflicting writes
s = txn->Commit();
if (s.ok()) {
  // Success
} else if (s.IsBusy()) {
  // Conflict detected, retry transaction
}

delete txn;
delete txn_db;