schemas/vegbien.sql: specimenreplicate: institution_id: Fixed typo in comment

inputs/import.stats.xls: Fixed date for most recent import

sql.py: DbConn.run_query(): Put the data source comment on a separate line in the log file instead of using a carriage return, which sometimes had the desired effect of overwriting the src comment with the first line of the query but sometimes the line lengths weren't right and there wasn't enough overlap

schemas/vegbien.ERD.mwb: Synced with schema

schemas/vegbien.sql: Removed per-column indexes, which are no longer needed by either row-based or column-based import because they are able to do a merge join or lookup using the table's UNIQUE INDEX. Instead of forcing the database to build and maintain large indexes (15+ GB!) that are not used, optimization-only (non-UNIQUE) indexes should be added as needed only once the database is actually used for queries. In most cases it will not even be necessary to add additional indexes then, because most UNIQUE indexes can be reused for broad lookups (rather than just duplicate elimination). Even the foreign key covering indexes (fki_*) are not needed because we virtually never delete rows in the DB, and even if we were to start doing that regularly, the cost of maintaining the indexes on import is most likely not worth the speed improvements for cascading deletes.

schemas/py_functions.sql: Removed per-column indexes on relational functions, which are no longer needed by row-based import because it is able to do a merge join-style lookup using the table's UNIQUE INDEX. (Note that column-based import doesn't use the (slower) relational functions at all anymore, and instead calls the corresponding SQL function directly using named arguments.)

schemas/functions.sql: Removed per-column indexes on relational functions, which are no longer needed by row-based import because it is able to do a merge join-style lookup using the table's UNIQUE INDEX. (Note that column-based import doesn't use the (slower) relational functions at all anymore, and instead calls the corresponding SQL function directly using named arguments.)

schemas/vegbien.sql: plantname: plantname_unique UNIQUE INDEX: Moved scope_id to the back so that the index can easily be used for lookup queries (not just column-based import) without having to explicitly specify NULL for that field. This takes advantage of a btree sorting feature where a broader lookup can be done using just the first n columns of the index.

schemas/vegbien.sql: locationevent, specimenreplicate: Turned UNIQUE CONSTRAINTs and UNIQUE INDEXes with nullable fields into partial UNIQUE INDEXes with IS NOT NULL filter conditions, in order to work automatically with sql_gen without requiring a separate covering lookup index. Removed no longer needed covering lookup indexes.

sql_io.py: put_table(): DuplicateKeyException: Fixed bug where combining multiple unique constraints was incorrectly allowed, when in fact the constraints need to be separately applied to the different rows that violate them, which is not currently supported