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I'm storing a lot of documents (TREC-9 corpus) in a Doc class/table
created using declarative_base():
class Doc(Base):
__tablename__ = 'doc'
id = Column(Integer, primary_key=True)
I = Column(Integer, index=True) # .I sequential identifier
U = Column(Integer, index=True) # .U MEDLINE identifier (UI)
(<DOCNO> used for relevance judgements)
M = Column(String, index=True) # .M Human-assigned MeSH
terms (MH)
...
The problem is INSERTs on such table (PG 9.1) are slowing down more
and more as docs are added. So I dropped indexes:
def drop_indexes(cls, eng):
conn = eng.connect()
indexes = cls.metadata.tables[cls.__tablename__].indexes
for idx in indexes:
conn.execute(DropIndex(idx))
(incidentally, is there a better/simpler way of dropping all indexes
for a given mapping class?)
Now all batches of INSERTs (grouped in 10,000 records transactions)
have around linear execution time.
Dandy. But how can I recreate the indexes now that I dropped them and
they were created automatically by passing kw argument (index=True) to
Column?
Regards,
mk
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