TESTS TO ADD

* CACHE-TABLE-QUERIES
* Test that ":db-kind :key" adds an index for that key. This is complicated by different
  backends showing autogenerated primary key in different ways.
* Test bigint type
* :db-constraint tests
* test *db-auto-sync* 
* for-each-row macro
* universal-time 

COMMONSQL INCOMPATIBILITY

<<<<<<< .mine
  o Complete sql expressions (see operations.lisp)

      nvl (Oracle specific) 
      userenv (Oracle specific) 
      minus (Oracle specific: does the same as EXCEPT) 
      || 

=======
>>>>>>> .r9364
   o variables (e.g., table identifiers) should be instantiated at runtime 

<<<<<<< .mine
=======
 >> The functional sql interface 
  
    SELECT 
      o keyword arg :refresh should function as advertised 

 >> Symbolic SQL syntax 

      o userenv (Oracle specific but deprecated in Oracle 9) 

VARIANCES FROM COMMONSQL

UPDATE-OBJECT-JOINS:
 Rather than simply reading the values for each
 object, to meet CommonSQL spec need to generate a single
 query to read values for all objects, up to max-len count.

>>>>>>> .r9364
COMMIT,ROLLBACK,START-TRANSACTION: 
 When COMMIT or ROLLBACK are called outside of WITH-TRANSACTION, an sql 
 transaction must be explicitly started first with START-TRANSACTION. 

OPTIMIZATIONS
 
* Revisit result-type list creation, perhaps caching

POSSIBLE EXTENSIONS

* extend large object support to databases beyond postgresql, improve large object api
* add support for prepared statements
* port Oracle backend to UFFI


NOTES ABOUT THE BACKENDS

MYSQL 

drop-index:   requires a table to be specified with the :from keyword parameter
views:        mysql does not support views  
queries:      nested subqueries are not supported
syntax:       doesn't support the sql concatenation operator (||). 

SQLITE 

create-view:  column-list parameter not supported 
syntax:       doesn't support the sql SUBSTRING operator.