- column labels are now generated in the compilation phase, which

means their lengths are dialect-dependent.  So on oracle a label
that gets truncated to 30 chars will go out to 63 characters
on postgres.  Also, the true labelname is always attached as the
accessor on the parent Selectable so theres no need to be aware
of the genrerated label names [ticket:512].
- ResultProxy column targeting is greatly simplified, and relies
upon the ANSICompiler's column_labels map to translate the built-in
label on a _ColumnClause (which is now considered to be a unique
identifier of that column) to the label which was generated at compile
time.
- still need to put a baseline of ColumnClause targeting for
ResultProxy objects that originated from a textual query.

1 files changed, 3 insertions, 0 deletions

diff --git a/lib/sqlalchemy/databases/postgres.py b/lib/sqlalchemy/databases/postgres.py
index 93f20889c..43d570070 100644
--- a/lib/sqlalchemy/databases/postgres.py
+++ b/lib/sqlalchemy/databases/postgres.py
@@ -279,6 +279,9 @@ class PGDialect(ansisql.ANSIDialect):
     def create_execution_context(self):
         return PGExecutionContext(self)
 
+    def max_identifier_length(self):
+        return 68
+        
     def type_descriptor(self, typeobj):
         if self.version == 2:
             return sqltypes.adapt_type(typeobj, pg2_colspecs)