[Sqlalchemy-tickets] Issue #4196: support sharded query for bulk update/delete methods (zzzeek/sqlalchemy)

[Michael B. <iss...@bi...>]

New issue 4196: support sharded query for bulk update/delete methods
https://bitbucket.org/zzzeek/sqlalchemy/issues/4196/support-sharded-query-for-bulk-update

Michael Bayer:

ongoing effort at https://gerrit.sqlalchemy.org/#/c/zzzeek/sqlalchemy/+/656/.    
this needs to include tests with the sharded query itself, including all three fetch methods.

additional issue:  

> Got a problem when synchronize_session='fetch'. In that case used BulkFetch._do_pre_synchronize (as you know :)). There is query instance with set `_bind_id` attribute, but it don't passed through `execute`.

> Here is an example that can illustrate that problem: https://gist.github.com/aCLr/a992ca92138aeee86bf9432693be6d6c
It contains Query and Session implementations, which used in my project: MultiBoundQuery and MultiBoundSession.
Also, it contains `delete` and `update` execution and checking for update and delete operation. Tracebacks included.