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Implement feature of new FE/BE protocol whereby RowDescription identifies

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the column by table OID and column number, if it's a simple column
reference.  Along the way, get rid of reskey/reskeyop fields in Resdoms.
Turns out that representation was not convenient for either the planner
or the executor; we can make the planner deliver exactly what the
executor wants with no more effort.
initdb forced due to change in stored rule representation.
This commit is contained in:
Tom Lane
2003-05-06 00:20:33 +00:00
parent 94a3c60324
commit 2cf57c8f8d
32 changed files with 454 additions and 336 deletions
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37
src/include/nodes/primnodes.h
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@@ -10,7 +10,7 @@
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: primnodes.h,v 1.81 2003/04/08 23:20:04 tgl Exp $
* $Id: primnodes.h,v 1.82 2003/05/06 00:20:33 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -30,7 +30,16 @@
* Resdom (Result Domain)
*
* Notes:
* ressortgroupref is the parse/plan-time representation of ORDER BY and
*
* resno will normally be equal to the item's position in a targetlist,
* but the code generally tries to avoid relying on that (eg, we avoid
* using "nth()" rather than a search to find an item by resno).
*
* resname will be null if no name can easily be assigned to the column.
* But it should never be null for user-visible columns (i.e., non-junk
* columns in a toplevel targetlist).
*
* ressortgroupref is used in the representation of ORDER BY and
* GROUP BY items. Targetlist entries with ressortgroupref=0 are not
* sort/group items. If ressortgroupref>0, then this item is an ORDER BY or
* GROUP BY value. No two entries in a targetlist may have the same nonzero
@@ -39,27 +48,25 @@
* ressortgroupref means a more significant sort key.) The order of the
* associated SortClause or GroupClause lists determine the semantics.
*
* reskey and reskeyop are the execution-time representation of sorting.
* reskey must be zero in any non-sort-key item. The reskey of sort key
* targetlist items for a sort plan node is 1,2,...,n for the n sort keys.
* The reskeyop of each such targetlist item is the sort operator's OID.
* reskeyop will be zero in non-sort-key items.
* resorigtbl/resorigcol identify the source of the column, if it is a
* simple reference to a column of a base table (or view). If it is not
* a simple reference, these fields are zeroes.
*
* Both reskey and reskeyop are typically zero during parse/plan stages.
* The executor does not pay any attention to ressortgroupref.
* If resjunk is true then the column is a working column (such as a sort key)
* that should be removed from the final output of the query.
*--------------------
*/
typedef struct Resdom
{
NodeTag type;
AttrNumber resno; /* attribute number */
AttrNumber resno; /* attribute number (1..N) */
Oid restype; /* type of the value */
int32 restypmod; /* type-specific modifier of the value */
char *resname; /* name of the resdom (could be NULL) */
Index ressortgroupref;
/* nonzero if referenced by a sort/group clause */
Index reskey; /* order of key in a sort (for those > 0) */
Oid reskeyop; /* sort operator's Oid */
char *resname; /* name of the column (could be NULL) */
Index ressortgroupref; /* nonzero if referenced by a
* sort/group clause */
Oid resorigtbl; /* OID of column's source table */
AttrNumber resorigcol; /* column's number in source table */
bool resjunk; /* set to true to eliminate the attribute
* from final target list */
} Resdom;