scans are candidates for exclusion; this should be fixed eventually.
Simon Riggs, with some help from Tom Lane.

logic operations during planning.  Seems cleaner to create two new Path
node types, instead --- this avoids duplication of cost-estimation code.
Also, create an enable_bitmapscan GUC parameter to control use of bitmap
plans.

functions with OUT parameters.  The various PLs still need work, as does
pg_dump.  Rudimentary docs and regression tests included.

>>ISTM that "source" is worth knowing.
>
> Hm, possibly.  Any other opinions?

This version has the seven fields I proposed, including "source". Here's
an example that shows why I think it's valuable:

regression=# \x
Expanded display is on.
regression=# select * from pg_settings where name = 'enable_seqscan';
-[ RECORD 1 ]-----------
name    | enable_seqscan
setting | on
context | user
vartype | bool
source  | default
min_val |
max_val |

regression=# update pg_settings set setting = 'off' where name =
'enable_seqscan';
-[ RECORD 1 ]---
set_config | off

regression=# select * from pg_settings where name = 'enable_seqscan';
-[ RECORD 1 ]-----------
name    | enable_seqscan
setting | off
context | user
vartype | bool
source  | session
min_val |
max_val |

regression=# alter user postgres set enable_seqscan to 'off';
ALTER USER

(log out and then back in again)

regression=# \x
Expanded display is on.
regression=# select * from pg_settings where name = 'enable_seqscan';
-[ RECORD 1 ]-----------
name    | enable_seqscan
setting | off
context | user
vartype | bool
source  | user
min_val |
max_val |

In the first case, enable_seqscan is set to its default value. After
setting it to off, it is obvious that the value has been changed for the
session only. In the third case, you can see that the value has been set
specifically for the user.

Joe Conway

of the containing query (which really can only happen in a rule context).
Per example from Brandon Craig Rhodes.  Also, make the error message
more specific for the similar case with sub-select in FROM.  The revised
coding should be easier to adapt to SQL99's LATERAL(), when we get around
to supporting that.

parameter to allow it to be forced off for comparison purposes.
Add ORDER BY clauses to a bunch of regression test queries that will
otherwise produce randomly-ordered output in the new regime.

types, SRFs.  Not happy with memory management yet, but I'll commit these
other changes.

rangefunc regression test for the new behavior.

Joe Conway

to build dependencies for rules, constraint expressions, and default
expressions.  Repair some problems in the original design of
recursiveDeletion() exposed by more complex dependency sets.  Fix
regression tests that were deleting things in illegal sequences.