MetaData.sorted_tables is inconsistant

[Ofir Herzas]

It seems that MetaData.sorted_tables returns a different result each time.

While the results seem to be always correct, it is an odd behavior.

I would expect sorted_tables to return the same results every time

import sqlalchemy as sa
engine = sa.create_engine("<db_url>", echo=False)

meta = sa.MetaData(bind=engine, reflect=True)
a = [t.name for t in meta.sorted_tables]

meta = sa.MetaData(bind=engine, reflect=True)
b = [t.name for t in meta.sorted_tables]

a and b are not sorted the same

BTW: meta.tables is consistent ...

[Mike Bayer]

On 6/14/15 9:06 AM, Ofir Herzas wrote:

It seems that MetaData.sorted_tables returns a different result each time.

While the results seem to be always correct, it is an odd behavior.

A topological sort is non-deterministic.   If two elements A and B have no dependency on each other, they can be returned in either order.

However, the sorted_tables accessor was  specifically enhanced to use a deterministic sorting in 1.0, where the list of items passed to the topological algorithm is first sorted alphabetically, and an ordered set is used internally, so that it comes up with the same result each time.

So, did you try 1.0 ?

I would expect sorted_tables to return the same results every time

import sqlalchemy as sa
engine = sa.create_engine("<db_url>", echo=False)

meta = sa.MetaData(bind=engine, reflect=True)
a = [t.name for t in meta.sorted_tables]

meta = sa.MetaData(bind=engine, reflect=True)
b = [t.name for t in meta.sorted_tables]

a and b are not sorted the same

BTW: meta.tables is consistent ...

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[Ofir Herzas]

Nope, I still use 0.9.7 J

It's not a big deal, just seemed odd, but thanks, I will look at it again once I move to 1.0 …

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