Hello, I just chased down a bug in our application while using SQLAlchemy 1.0.6 in an Oracle RAC environment, which should probably be in SQLAlchemy documentation somewhere, and possibly motivate a change to the options for sequence creation on Oracle.
Basically, our application assumes a column we attach a sqlalchemy.Sequence to will always increment, and we use that to process a set of changes in strict order. However, if you read the Oracle docs on SEQUENCE creation (here: https://docs.oracle.com/cd/B12037_01/server.101/b10759/statements_6014.htm), in an RAC environment, that is not true by default - each node running your database grabs a cache of sequence numbers to serve out equal to CACHE size (default is 20) and whichever node processes your insert will assign a sequence number from its cache. I understand this is done for performance reasons, and in the very common case that all you want from your Sequence is to autogenerate a unique id, it's absolutely fine. However, it would be nice to have an option to specify the ORDER keyword when creating your SEQUENCE if you really need a Sequence in sequential order, and a documentation note that this is an oddity of Oracle RAC. Kind regards, Dave Moore -- SQLAlchemy - The Python SQL Toolkit and Object Relational Mapper http://www.sqlalchemy.org/ To post example code, please provide an MCVE: Minimal, Complete, and Verifiable Example. See http://stackoverflow.com/help/mcve for a full description. --- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at https://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
