Block.One recently released introduced a new alpha support for a new and more robust blockchain history tool based on RocksDB instead of postgresql. RocksDB is an embeddable persistent key-value store for fast storage and it is optimized for fast, low latency storage.
In their latest article, Block.One provided an overview of blockchain history solutions on EOSIO and a simplified architecture diagram explaining tools available for application developers.
"Currently, RocksDB outperforms LMDB and PostgreSQL databases by considerable margins for both partial and full blockchain history on EOSIO blockchains. RocksDB also stores the full history much more efficiently than PostgreSQL."
Read more: https://eos.io/news/eosio-history-tools/