Index stored in LevelDB
'b' + 32-byte block hash -> block index record. : The block header. The height. The number of transactions. To what extent this block is validated. In which file, and where in that file, the block data is stored. In which file, and where in that file, the undo data is stored. 'f' + 4-byte file number -> file information record. The number of blocks stored in the block file with that number. The size of the block file with that number ($DATADIR/blocks/blkNNNNN.dat). The size of the undo file with that number ($DATADIR/blocks/revNNNNN.dat). The lowest and highest height of blocks stored in the block file with that number. The lowest and highest timestamp of blocks stored in the block file with that number. 'l' -> 4-byte file number: the last block file number used. 'R' -> 1-byte boolean ('1' if true): whether we're in the process of reindexing. 'F' + 1-byte flag name length + flag name string -> 1 byte boolean ('1' if true, '0' if false): various flags that can be on or off. Currently defined flags include: 'txindex': Whether the transaction index is enabled. 't' + 32-byte transaction hash -> transaction index record. These are optional and only exist if 'txindex' is enabled (see above). : Which block file number the transaction is stored in. Which offset into that file the block the transaction is part of is stored at. The offset from the start of that block to the position where that transaction itself is stored.
'c' + 32-byte transaction hash -> unspent transaction output record for that transaction. These records are only present for transactions that have at least one unspent output left.: The version of the transaction. Whether the transaction was a coinbase or not. Which height block contains the transaction. Which outputs of that transaction are unspent. The scriptPubKey and amount for those unspent outputs. 'B' -> 32-byte block hash: the block hash up to which the database represents the unspent transaction outputs.