Database

Safex blockchain uses LMDB for storing data. LMDB is an abbreviation for Lighting Memory-Mapped Database. It is a software library that provides a high-performance embedded transactional database in form of a key-value store. There are 25 tables used in the Safex blockchain. 15 out of that 25 are the same tables used in Monero and a table for token amounts. The other 10 tables are:

Table name	Key	Key type	Value	Value type
m_output_advanced	output_id	uint64_t	Output advanced data	output_advanced_data_t (blockchain_db.h:153)
m_output_advanced_type	output_type	tx_out_type	Output key	outkey_advanced
m_token_staked_sum	interval	uint64_t	staked tokens
m_token_staked_sum_total	zero	uint64_t	total staked tokens
m_network_fee_sum	interval	uint64_t	SFX amount given to network fee
m_token_lock_expiry	block number	uint64_t	output id
m_safex_account	username	string	create_account_result
m_safex_offer	offer id	crypto::hash	create_offer_result
m_safex_feedback	offer id	crypto::hash	safex_feedback_db_data
m_safex_price_peg	price peg id	crypto::hash	create_price_peg_result

After every advanced transaction, m_output_advanced and m_output_advanced_type are each filled with one additional row. Additionally, depending on the transaction, a proper table is also updated.

If a new table needs to be added due to a new transaction type created, the maximum number of tables created must be changed in the code:

if ((result = mdb_env_set_maxdbs(m_env, 25)))