deterministic names now, based on their ordering within the
full statement being compiled. this means the same statement
will produce the same string across application restarts and
allowing DB query plan caching to work better.
- cleanup to sql.ClauseParameters since it was just falling
apart, API made more explicit
- many unit test tweaks to adjust for bind params not being
"pre" truncated, changes to ClauseParameters
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.
Mike Bayer