Ok, thank you. I'll see how that goes. sob., 11 sie 2018 o 01:26 Mike Bayer <clas...@zzzcomputing.com> napisał(a):
> > > On Fri, Aug 10, 2018, 4:23 PM Michał Bultrowicz < > michalbultrow...@gmail.com> wrote: > >> Thanks, but how can I inspect the revisions in code? I'd need to provide >> some special markers on the ones I don't want to surround in a transaction. >> > > That database code is in the migration file itself. The approach > doesn't imply changes to env.py. > > > > >> pt., 10 sie 2018 o 20:50 Mike Bayer <mike...@zzzcomputing.com> >> napisał(a): >> >>> On Fri, Aug 10, 2018 at 2:00 PM, Michał Bultrowicz >>> <michalbultrow...@gmail.com> wrote: >>> > Hey! >>> > >>> > What approach would you recommend if we want to run some revisions >>> outside >>> > of a transaction, but then run the other ones normally? >>> > >>> > Let me illustrate that. Let's say we have revisions 1,2,3,4,5. The >>> database >>> > is currently at revision 1, so we need to run 2-5. The problem is that >>> 4 is >>> > an operation that can't be in a transation, specifically CREATE INDEX >>> > CONCURRENTLY from Postgres (synchronous creation of the index would >>> block >>> > writes to a table, which is unacceptable in production). >>> > So we'd like to run, 2 and 3 in a transaction, then do 4 outside of a >>> > transactionand wait for it, then run 5 in a transaction. >>> >>> >>> so you want to set transaction_per_migration: >>> >>> >>> http://alembic.zzzcomputing.com/en/latest/api/runtime.html?highlight=transaction_per_migration#alembic.runtime.environment.EnvironmentContext.configure.params.transaction_per_migration >>> >>> you're still safe if 1,2,3 or 5 fail since they are in their own >>> transaction and it will stop at that migration if a problem happens. >>> >>> then in migration 4, inside the migration script get a separate >>> connection, which has to be an ".autocommit' connection with psycopg2: >>> >>> with >>> op.get_bind().engine.connect().execution_options(isolation_level='AUTOCOMMIT') >>> as conn: >>> conn.execute("CREATE INDEX CONCURRENTLY") >>> >>> >>> >>> >>> >>> >>> >>> > >>> > In run_migrations_online (we don't use offline) there's this bit >>> > with sql_engine.connect() as connection: >>> > with context.begin_transaction(): >>> > context.run_migrations() >>> > >>> > Can we get access to the list of revisions here and bundle them up >>> however >>> > we want? >>> > >>> > Best regards, >>> > Michał Bultrowicz >>> > >>> > -- >>> > You received this message because you are subscribed to the Google >>> Groups >>> > "sqlalchemy-alembic" group. >>> > To unsubscribe from this group and stop receiving emails from it, send >>> an >>> > email to sqlalchemy-alembic+unsubscr...@googlegroups.com. >>> > For more options, visit https://groups.google.com/d/optout. >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "sqlalchemy-alembic" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to sqlalchemy-alembic+unsubscr...@googlegroups.com. >>> For more options, visit https://groups.google.com/d/optout. >>> >> -- >> You received this message because you are subscribed to the Google Groups >> "sqlalchemy-alembic" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to sqlalchemy-alembic+unsubscr...@googlegroups.com. >> For more options, visit https://groups.google.com/d/optout. >> > -- > You received this message because you are subscribed to the Google Groups > "sqlalchemy-alembic" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sqlalchemy-alembic+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "sqlalchemy-alembic" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy-alembic+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
