New documents added to firebird 2.0 Unstable by Dmitry Yemanov

Changes can be traced in the What's new text file on sourceforge . Some documents are not added yet.

* SQL improvements:

       1) Introduced SEQUENCE as a synonym for GENERATOR (as per SQL-99)

       2) Added SQL-99 compliant NEXT VALUE FOR

       3) Implemented REVOKE ADMIN OPTION FROM statement

       See also:

       /doc/sql.extentions/README.sequence_generators

       /doc/sql.extentions/README.ddl.txt

* ISQL improvement:

       Command line switch -b to bail out on error when used in non-interactive mode.

       Also,return an error code to the operating system.

       See also:/doc/README.isql_enhancements.txt



* Context variables

       Added support for context variables via RDB$GET_CONTEXT and RDB$SET_CONTEXT system functions

       See also:/doc/sql.extentions/README.context_variables2



* SQL improvement:

       Allowed PLAN, ROWS and ORDER BY clauses in UPDATE/DELETE statements

       See also:/doc/sql.extentions/README.select_expressions

       Added an equivalence predicate which behaves exactly as equality/inequality, but treats NULL = NULL as TRUE

       Syntax: A IS [NOT] DISTINCT FROM B

       See also:/doc/sql.extentions/README.distinct



* More SQL improvements:

       1) Allowed FIRST/SKIP/ROWS/PLAN and ORDER BY clauses in views

       2) Added CROSS JOIN (A CROSS JOIN B means something like A INNER JOIN B ON 1 = 1 or just FROM A, B)

       3) Allowed UNION in subqueries and INSERT statement

       See also:/doc/sql.extentions/README.select_expressions



* UDF improvement:

      Ability to signal SQL NULL via a NULL pointer

      See also: /doc/sql.extentions/README.ddl.txt

     

* Expression indices:

      Implemented indices based on arbitrary expressions

      Syntax: CREATE [UNIQUE] [ASC[ENDING] | DESC[ENDING]] INDEX  ON  (  )

      See also:/doc/sql.extentions/README.expression_indices



* IIF builtin function :

      Added IIF (, , ) as a shortcut for CASE WHEN  THEN  ELSE  END

      See also:

/doc/sql.extentions/README.iif



* Improved ISQL:

      1) Fixed bug SF #910430 - ISQL and database dialect

      2) Add SET HEADING ON/OFF option

      3) Add -M2 command-line option to send output of statistics and plans to the same file than the rest of the output

      See also:/doc/README.isql_enhancements.txt



* New database shutdown modes are introduced Single-user and full

      shutdown modes are implemented

      See also:/doc/README.shutdown_modes.txt



* Implemented EXECUTE BLOCK statement It is now possible to use dynamic PSQL with this statement

      See also:/doc/sql.extentions/README.execute_block



* Implemented support for default parameters for stored procedures

 See also:/doc/sql.extentions/README.default_parameters



* Re-worked logic of updatable views This solves problems with views that are implicitly updatable,but still have update triggers

       See also:/doc/sql.extentions/README.view_updates



* Added SQL200X ROWS clause New syntax to limit amount of records you want to get

       See also:/doc/sql.extentions/README.rows



* Support for explicit cursor syntax in PSQL It is now possible to declare and use multiple cursors in PSQL

 See also:/doc/sql.extentions/README.cursors



* Improved PLAN clause Allowed to specify more possible paths for the engine

       Example: PLAN (A ORDER IDX1 INDEX(IDX2, IDX3))

       See also:/doc/sql.extentions/README.plan



* Added LEAVE syntax support PSQL loops now may be marked with labels and terminated in Java style

       See also:/doc/sql.extentions/README.leave_labels



* Improved ROW_COUNT Now it's possible to get number of selected rows as well

       See also: /doc/sql.extentions/README.context_variables



* Derived tables support Implemented support for derived tables in DSQL (subqueries in FROM clause) as defined by SQL200X

      See also:/doc/sql.extentions/README.derived_tables.txt



* New backup technology Implemented fast on-line physical incremental backup facilities

      See also: /doc/README.nbackup.txt



* Generic cleanup. Various cleaning and tidying up of code, warnings removal,64-bitness cleanup, numerous minor bugfixes