TODO: GRANT/REVOKE: Allow column-level privileges

Fellow Hackers,

I've been working on this item for a little while, and I'm starting to see
some code come together.  I wanted to solicit some feedback before I got
too far along to make sure I'm on the right track.

Here's a rough overview of what I've done so far:

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PARSER:
* modified parser to accept SQL column privs syntax
* created a PrivAttr Node which holds ( priv, attr[] ) pairs.  Currently,  it's just a list of strings.  For example,
whenyou call...
 
GRANT SELECT, UPDATE (col1, col2) ON table1, table2 to grantee;
  ... the parser creates a list of Nodes:
("select", NIL), ("update", ("col1", "col2"))

SYSTEM CATALOG:
* add "attacl aclinfo[]" column to pg_attribute table and Form_pg_attribute.* add OID column to pg_attribute.  This
permitsdependencies to be  registered correctly in pg_shdepend.* populated attacl column in existing pg_attribute
bootstrapwith NULLs* allocated an unused oid for each of the pg_attribute rows that are  bootstrapped* created an oid
indexon pg_attribute
 
* modified ExecuteGrantStmt to handle the PrivAttr structure instead of  the list of strings* modified ExecuteGrantStmt
todo a nested loop over all  (column,relation) pairs in the GRANT and find oids for all of the  attributes.
 

PSQL COMMAND LINE:
* display column privileges with  "\d+ table"

STILL LEFT TO DO:
* implement ExecGrant_Attribute() to modify pg_attribute* verify query against column privileges in addition to table
privileges*register dependencies* pg_dump column privileges
 

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I'd welcome any feedback on the design changes I've made, or any other
potential snags I should watch out for.

Thanks.

-- kevin brintnall =~ <kbrint@rufus.net>