[lmdb #10] Set mapsize to 1TB by default for r/w DBs

[simonmar]

From the comment:

 // LMDB needs us to pre-set the memory map size, which determines
 // the maximum size of the DB. Setting it to zero uses the mapsize
 // when the DB was created, while setting it to a value smaller than
 // the actual size of the DB causes LMDB to use the DB size - this
 // is what we want for a read-only DB. For a read/write DB we have
 // to pick a huge value, because the mapsize can only be increased
 // if there are no transactions in progress, and we don't have a good
 // way to do that aside from closing and re-opening the DB.

[netlify]

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[iamirzhan]

ah, I am trying to run indexer internally and get [MDB_MAP_FULL](lmdb: MDB_MAP_FULL: Environment mapsize limit reached)` I guess that's why

[meta-codesync]

@iamirzhan has imported this pull request. If you are a Meta employee, you can view this in D91237978.