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> There's no longer a separate call to heap_storage_create in that routine > --- the right place to make the test is now in the storage_create > boolean parameter being passed to heap_create. A simple change, but > it passeth patch's understanding ... Thanks. Attached is a patch against cvs tip as of 8:30 PM PST or so. Turned out that even after fixing the failed hunks, there was a new spot in bufmgr.c which needed to be fixed (related to temp relations; RelationUpdateNumberOfBlocks). But thankfully the regression test code caught it :-) Joe Conway
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* *
* EXPLANATION OF THE NODE STRUCTURES *
* - Andrew Yu (11/94) *
* *
* Copyright (c) 1994, Regents of the University of California *
* *
* $Id: README,v 1.1.1.1 1996/07/09 06:21:32 scrappy Exp $
* *
*******************************************************************************
INTRODUCTION
The current node structures are plain old C structures. "Inheritance" is
achieved by convention. No additional functions will be generated. Functions
that manipulate node structures reside in this directory.
FILES IN THIS DIRECTORY
Node manipulation functions:
copyfuncs.c - copying a node
equalfuncs.c - comparing a node
outfuncs.c - convert a node to ascii representation
readfuncs.c - convert ascii representation back to a node
makefuncs.c - creator functions for primitive nodes
Node definitions:
nodes.h - define node tags (NodeTag)
pg_list.h - generic list
primnodes.h - primitive nodes
parsenodes.h - parse tree nodes
plannodes.h - plan tree nodes
relation.h - inner plan tree nodes
execnodes.h - executor nodes
memnodes.h - memory nodes
STEPS TO ADD A NODE
Suppose you wana define a node Foo:
1. add a tag (T_Foo) to the enum NodeTag in nodes.h (You may have to
recompile the whole tree after doing this.)
2. add the structure definition to the appropriate ???nodes.h file. If you
intend to inherit from, say a Plan node, put Plan as the first field of
you definition.
3. if you intend to use copyObject, equal, nodeToString or stringToNode,
add an appropriate function to copyfuncs.c, equalfuncs.c, outfuncs.c
and readfuncs.c accordingly. (Except for frequently used nodes, don't
bother writing a creator function in makefuncs.c)
HISTORICAL NOTE
Prior to the current simple C structure definitions, the Node structures
uses a pseudo-inheritance system which automatically generates creator and
accessor functions. Since every node inherits from LispValue, the whole thing
is a mess. Here's a little anecdote:
LispValue definition -- class used to support lisp structures
in C. This is here because we did not want to totally rewrite
planner and executor code which depended on lisp structures when
we ported postgres V1 from lisp to C. -cim 4/23/90