On Aug 27, 2009, at 1:42 PM, Sergey Samokhin wrote:
Hello. As I know upgrading database structure from one version to another is usually done by applying some sql-script with a set of ALTER's that do all the work. But how do programmers guarantee that ALTER's they have wrote will always be applied by administrators to the corresponding version of the database?
In the application is where I do it, though it would be possible to create a .sql script that errored out if the existing version were not the one it expected.
Is there a standard way to store some kind of metainformation in DB (like version of the current definitions of tables) and then check if it is too old for being upgraded by a given script?
There's no standard way at the database level, though there are application frameworks that support it in a way that's standard for that framework.
By "database structure" I mean definition of tables an application uses (data types, constraints, modificators etc), stored procedures etc.
I tend to keep a single row table in the database that contains the current schema version, then have the application apply upgrade / downgrade patches as needed (or bail out and tell the user to do it). Cheers, Steve -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
