On 7/23/2014 1:45 PM, Seamus Abshere wrote:
What if we treat atomicity as optional? You could have extremely
readable syntax like:
atomicity is not and never will be optional in PostgreSQL.
-- no guarantees, no index required
UPSERT age = 5 INTO dogs WHERE name = 'Jerry';
and if there's several rows with name='Jerry', you'd want to update them
ALL ? if name isn't indexed, this will, as Tom suggests, require a FULL
table scan, and it still will have issues with concurrency (connection
scans table, finds nothing, starts to insert, user 2 scans table, finds
nothing, starts to insert, poof, now we have two records?!?). If name
*is* indexed and unique, this collision will cause a error at commit for
at least one of those connections.
--
john r pierce 37N 122W
somewhere on the middle of the left coast
