On Sat, Jun 11, 2011 at 03:03:18PM -0400, Tom Lane wrote:
> Noah Misch <n...@leadboat.com> writes:
> > Good points. I'm thinking, then, add an Expr argument to
> > simplify_function()
> > and have the CoerceViaIO branch of eval_const_expressions_mutator() pass
> > NULL
> > for both its simplify_function() calls. If simplify_function() gets a NULL
> > Expr
> > for a function that has a protransform, synthesize a FuncExpr based on its
> > other
> > arguments before calling the transform function. Seem reasonable? Granted,
> > that would be dead code until someone applies a transform function to a
> > type I/O
> > function, which could easily never happen. Perhaps just ignore the
> > transform
> > function when we started with a CoerceViaIO node?
>
> Until we actually have a use-case for simplifying I/O functions like this,
> I can't see going out of our way for it ...
Sounds good. Updated patch attached, incorporating your ideas. Before applying
it, run this command to update the uninvolved pg_proc.h DATA entries:
perl -pi -e 's/PGUID(\s+\d+){4}/$& 0/' src/include/catalog/pg_proc.h
Thanks,
nm
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index 8504555..5d1a447 100644
*** a/doc/src/sgml/catalogs.sgml
--- b/doc/src/sgml/catalogs.sgml
***************
*** 4337,4342 ****
--- 4337,4349 ----
</row>
<row>
+ <entry><structfield>protransform</structfield></entry>
+ <entry><type>regproc</type></entry>
+ <entry><literal><link
linkend="catalog-pg-proc"><structname>pg_proc</structname></link>.oid</literal></entry>
+ <entry>Calls to function can be simplified by this other
function</entry>
+ </row>
+
+ <row>
<entry><structfield>proisagg</structfield></entry>
<entry><type>bool</type></entry>
<entry></entry>
diff --git a/src/backend/catalog/index 6250b07..92be0a7 100644
*** a/src/backend/catalog/pg_proc.c
--- b/src/backend/catalog/pg_proc.c
***************
*** 304,309 **** ProcedureCreate(const char *procedureName,
--- 304,310 ----
values[Anum_pg_proc_procost - 1] = Float4GetDatum(procost);
values[Anum_pg_proc_prorows - 1] = Float4GetDatum(prorows);
values[Anum_pg_proc_provariadic - 1] = ObjectIdGetDatum(variadicType);
+ values[Anum_pg_proc_protransform - 1] = ObjectIdGetDatum(InvalidOid);
values[Anum_pg_proc_proisagg - 1] = BoolGetDatum(isAgg);
values[Anum_pg_proc_proiswindow - 1] = BoolGetDatum(isWindowFunc);
values[Anum_pg_proc_prosecdef - 1] = BoolGetDatum(security_definer);
diff --git a/src/backend/commands/taindex 2c9f855..563a1b2 100644
*** a/src/backend/commands/tablecmds.c
--- b/src/backend/commands/tablecmds.c
***************
*** 56,61 ****
--- 56,62 ----
#include "nodes/nodeFuncs.h"
#include "nodes/parsenodes.h"
#include "optimizer/clauses.h"
+ #include "optimizer/planner.h"
#include "parser/parse_clause.h"
#include "parser/parse_coerce.h"
#include "parser/parse_collate.h"
***************
*** 3495,3501 **** ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap,
LOCKMODE lockmode)
{
NewColumnValue *ex = lfirst(l);
! ex->exprstate = ExecPrepareExpr((Expr *) ex->expr, estate);
}
notnull_attrs = NIL;
--- 3496,3503 ----
{
NewColumnValue *ex = lfirst(l);
! /* expr already planned */
! ex->exprstate = ExecInitExpr((Expr *) ex->expr, NULL);
}
notnull_attrs = NIL;
***************
*** 4398,4404 **** ATExecAddColumn(List **wqueue, AlteredTableInfo *tab,
Relation rel,
newval = (NewColumnValue *)
palloc0(sizeof(NewColumnValue));
newval->attnum = attribute.attnum;
! newval->expr = defval;
tab->newvals = lappend(tab->newvals, newval);
tab->rewrite = true;
--- 4400,4406 ----
newval = (NewColumnValue *)
palloc0(sizeof(NewColumnValue));
newval->attnum = attribute.attnum;
! newval->expr = expression_planner(defval);
tab->newvals = lappend(tab->newvals, newval);
tab->rewrite = true;
***************
*** 6706,6711 **** ATPrepAlterColumnType(List **wqueue,
--- 6708,6716 ----
/* Fix collations after all else */
assign_expr_collations(pstate, transform);
+ /* Plan the expr now so we can accurately assess the need to
rewrite. */
+ transform = (Node *) expression_planner((Expr *) transform);
+
/*
* Add a work queue item to make ATRewriteTable update the
column
* contents.
diff --git a/src/backend/optimizer/utilindex 2914c39..e9fb750 100644
*** a/src/backend/optimizer/util/clauses.c
--- b/src/backend/optimizer/util/clauses.c
***************
*** 106,114 **** static List *simplify_and_arguments(List *args,
eval_const_expressions_context
*context,
bool *haveNull, bool *forceFalse);
static Node *simplify_boolean_equality(Oid opno, List *args);
! static Expr *simplify_function(Oid funcid,
! Oid result_type, int32 result_typmod,
! Oid result_collid, Oid input_collid, List
**args,
bool has_named_args,
bool allow_inline,
eval_const_expressions_context *context);
--- 106,114 ----
eval_const_expressions_context
*context,
bool *haveNull, bool *forceFalse);
static Node *simplify_boolean_equality(Oid opno, List *args);
! static Expr *simplify_function(Expr *oldexpr, Oid funcid,
! Oid result_type, int32 result_typmod, Oid
result_collid,
! Oid input_collid, List **args,
bool has_named_args,
bool allow_inline,
eval_const_expressions_context *context);
***************
*** 2223,2229 **** eval_const_expressions_mutator(Node *node,
* FuncExpr, but not when the node is recognizably a length
coercion;
* we want to preserve the typmod in the eventual Const if so.
*/
! simple = simplify_function(expr->funcid,
expr->funcresulttype, exprTypmod(node),
expr->funccollid,
expr->inputcollid,
--- 2223,2230 ----
* FuncExpr, but not when the node is recognizably a length
coercion;
* we want to preserve the typmod in the eventual Const if so.
*/
! simple = simplify_function((Expr *) expr,
! expr->funcid,
expr->funcresulttype, exprTypmod(node),
expr->funccollid,
expr->inputcollid,
***************
*** 2275,2281 **** eval_const_expressions_mutator(Node *node,
* Code for op/func reduction is pretty bulky, so split it out
as a
* separate function.
*/
! simple = simplify_function(expr->opfuncid,
expr->opresulttype, -1,
expr->opcollid,
expr->inputcollid,
--- 2276,2283 ----
* Code for op/func reduction is pretty bulky, so split it out
as a
* separate function.
*/
! simple = simplify_function((Expr *) expr,
!
expr->opfuncid,
expr->opresulttype, -1,
expr->opcollid,
expr->inputcollid,
***************
*** 2372,2378 **** eval_const_expressions_mutator(Node *node,
* Code for op/func reduction is pretty bulky, so split
it out as
* a separate function.
*/
! simple = simplify_function(expr->opfuncid,
expr->opresulttype, -1,
expr->opcollid,
expr->inputcollid,
--- 2374,2381 ----
* Code for op/func reduction is pretty bulky, so split
it out as
* a separate function.
*/
! simple = simplify_function((Expr *) expr,
!
expr->opfuncid,
expr->opresulttype, -1,
expr->opcollid,
expr->inputcollid,
***************
*** 2561,2567 **** eval_const_expressions_mutator(Node *node,
getTypeOutputInfo(exprType((Node *) arg), &outfunc,
&outtypisvarlena);
getTypeInputInfo(expr->resulttype, &infunc, &intypioparam);
! simple = simplify_function(outfunc,
CSTRINGOID,
-1,
InvalidOid,
InvalidOid,
--- 2564,2571 ----
getTypeOutputInfo(exprType((Node *) arg), &outfunc,
&outtypisvarlena);
getTypeInputInfo(expr->resulttype, &infunc, &intypioparam);
! simple = simplify_function(NULL,
! outfunc,
CSTRINGOID,
-1,
InvalidOid,
InvalidOid,
***************
*** 2581,2587 **** eval_const_expressions_mutator(Node *node,
Int32GetDatum(-1),
false, true));
! simple = simplify_function(infunc,
expr->resulttype, -1,
expr->resultcollid,
InvalidOid,
--- 2585,2592 ----
Int32GetDatum(-1),
false, true));
! simple = simplify_function(NULL,
!
infunc,
expr->resulttype, -1,
expr->resultcollid,
InvalidOid,
***************
*** 3417,3427 **** simplify_boolean_equality(Oid opno, List *args)
* Subroutine for eval_const_expressions: try to simplify a function call
* (which might originally have been an operator; we don't care)
*
! * Inputs are the function OID, actual result type OID (which is needed for
! * polymorphic functions), result typmod, result collation,
! * the input collation to use for the function,
! * the pre-simplified argument list, and some flags;
! * also the context data for eval_const_expressions.
*
* Returns a simplified expression if successful, or NULL if cannot
* simplify the function call.
--- 3422,3436 ----
* Subroutine for eval_const_expressions: try to simplify a function call
* (which might originally have been an operator; we don't care)
*
! * Inputs are the original expression (can be NULL), function OID, actual
! * result type OID (which is needed for polymorphic functions), result typmod,
! * result collation, the input collation to use for the function, the
! * pre-simplified argument list, and some flags; also the context data for
! * eval_const_expressions. In common cases, several of the arguments could be
! * derived from the original expression. Sending them separately avoids
! * duplicating NodeTag-specific knowledge, and it's necessary for CoerceViaIO.
! * A NULL original expression disables use of transform functions while
! * retaining all other behaviors.
*
* Returns a simplified expression if successful, or NULL if cannot
* simplify the function call.
***************
*** 3433,3446 **** simplify_boolean_equality(Oid opno, List *args)
* pass-by-reference, and it may get modified even if simplification fails.
*/
static Expr *
! simplify_function(Oid funcid, Oid result_type, int32 result_typmod,
! Oid result_collid, Oid input_collid, List
**args,
bool has_named_args,
bool allow_inline,
eval_const_expressions_context *context)
{
HeapTuple func_tuple;
Expr *newexpr;
/*
* We have two strategies for simplification: either execute the
function
--- 3442,3457 ----
* pass-by-reference, and it may get modified even if simplification fails.
*/
static Expr *
! simplify_function(Expr *oldexpr, Oid funcid,
! Oid result_type, int32 result_typmod, Oid
result_collid,
! Oid input_collid, List **args,
bool has_named_args,
bool allow_inline,
eval_const_expressions_context *context)
{
HeapTuple func_tuple;
Expr *newexpr;
+ Oid transform;
/*
* We have two strategies for simplification: either execute the
function
***************
*** 3468,3473 **** simplify_function(Oid funcid, Oid result_type, int32
result_typmod,
--- 3479,3489 ----
result_collid,
input_collid, *args,
func_tuple,
context);
+ transform = ((Form_pg_proc) GETSTRUCT(func_tuple))->protransform;
+ if (!newexpr && OidIsValid(transform) && oldexpr)
+ newexpr = (Expr *) DatumGetPointer(OidFunctionCall1(transform,
+
PointerGetDatum(oldexpr)));
+
if (!newexpr && allow_inline)
newexpr = inline_function(funcid, result_type, result_collid,
input_collid,
*args,
diff --git a/src/backend/parser/parse_clausindex c5fe6b6..a8549e0 100644
*** a/src/backend/parser/parse_clause.c
--- b/src/backend/parser/parse_clause.c
***************
*** 2278,2280 **** transformFrameOffset(ParseState *pstate, int frameOptions,
Node *clause)
--- 2278,2302 ----
return node;
}
+
+ /*
+ * relabel_to_typmod
+ * Add a RelabelType node that changes just the typmod, and remove
all
+ * now-superfluous RelabelType nodes beneath it.
+ */
+ Node *
+ relabel_to_typmod(Node *expr, int32 typmod)
+ {
+ Oid type = exprType(expr);
+ Oid coll = exprCollation(expr);
+
+ /*
+ * Strip any existing RelabelType, then add one. This is to preserve the
+ * invariant of no redundant RelabelTypes.
+ */
+ while (IsA(expr, RelabelType))
+ expr = (Node *) ((RelabelType *) expr)->arg;
+
+ return (Node *) makeRelabelType((Expr *) expr, type, typmod, coll,
+
COERCE_DONTCARE);
+ }
diff --git a/src/backend/utils/adt/varchindex 1c0ef92..efa483d 100644
*** a/src/backend/utils/adt/varchar.c
--- b/src/backend/utils/adt/varchar.c
***************
*** 18,23 ****
--- 18,25 ----
#include "access/hash.h"
#include "access/tuptoaster.h"
#include "libpq/pqformat.h"
+ #include "nodes/nodeFuncs.h"
+ #include "parser/parse_clause.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "mb/pg_wchar.h"
***************
*** 549,554 **** varcharsend(PG_FUNCTION_ARGS)
--- 551,588 ----
/*
+ * Flatten calls to our length coercion function that leave the new maximum
+ * length >= the previous maximum length. We ignore the isExplicit argument,
+ * which only affects truncation.
+ */
+ Datum
+ varchar_transform(PG_FUNCTION_ARGS)
+ {
+ FuncExpr *expr = (FuncExpr *) PG_GETARG_POINTER(0);
+ Node *typmod;
+ Node *ret = NULL;
+
+ if (!IsA(expr, FuncExpr))
+ PG_RETURN_POINTER(ret);
+
+ Assert(list_length(expr->args) == 3);
+ typmod = lsecond(expr->args);
+
+ if (IsA(typmod, Const))
+ {
+ Node *source = linitial(expr->args);
+ int32 new_typmod = DatumGetInt32(((Const *)
typmod)->constvalue);
+ int32 old_max = exprTypmod(source) - VARHDRSZ;
+ int32 new_max = new_typmod - VARHDRSZ;
+
+ if (new_max < 0 || (old_max >= 0 && old_max <= new_max))
+ ret = relabel_to_typmod(source, new_typmod);
+ }
+
+ PG_RETURN_POINTER(ret);
+ }
+
+ /*
* Converts a VARCHAR type to the specified size.
*
* maxlen is the typmod, ie, declared length plus VARHDRSZ bytes.
diff --git a/src/include/catalog/pg_clindex ffcce3c..002ae6b 100644
*** a/src/include/catalog/pg_class.h
--- b/src/include/catalog/pg_class.h
***************
*** 134,140 **** DATA(insert OID = 1247 ( pg_type PGNSP 71 0
PGUID 0 0 0 0 0 0 0 f f p r 29 0 t
DESCR("");
DATA(insert OID = 1249 ( pg_attribute PGNSP 75 0 PGUID 0 0 0 0 0 0 0
f f p r 20 0 f f f f f 3 _null_ _null_ ));
DESCR("");
! DATA(insert OID = 1255 ( pg_proc PGNSP 81 0 PGUID 0 0 0 0 0 0 0
f f p r 25 0 t f f f f 3 _null_ _null_ ));
DESCR("");
DATA(insert OID = 1259 ( pg_class PGNSP 83 0 PGUID 0 0 0 0 0 0 0
f f p r 26 0 t f f f f 3 _null_ _null_ ));
DESCR("");
--- 134,140 ----
DESCR("");
DATA(insert OID = 1249 ( pg_attribute PGNSP 75 0 PGUID 0 0 0 0 0 0 0
f f p r 20 0 f f f f f 3 _null_ _null_ ));
DESCR("");
! DATA(insert OID = 1255 ( pg_proc PGNSP 81 0 PGUID 0 0 0 0 0 0 0
f f p r 26 0 t f f f f 3 _null_ _null_ ));
DESCR("");
DATA(insert OID = 1259 ( pg_class PGNSP 83 0 PGUID 0 0 0 0 0 0 0
f f p r 26 0 t f f f f 3 _null_ _null_ ));
DESCR("");
diff --git a/src/include/catalog/pg_pindex a66ecf1..6980d3e 100644
*** a/src/include/catalog/pg_proc.h
--- b/src/include/catalog/pg_proc.h
***************
*** 42,47 **** CATALOG(pg_proc,1255) BKI_BOOTSTRAP BKI_ROWTYPE_OID(81)
BKI_SCHEMA_MACRO
--- 42,48 ----
float4 procost; /* estimated execution cost */
float4 prorows; /* estimated # of rows out (if
proretset) */
Oid provariadic; /* element type of variadic
array, or 0 */
+ regproc protransform; /* transforms calls to it during
planning */
bool proisagg; /* is it an aggregate? */
bool proiswindow; /* is it a window function? */
bool prosecdef; /* security definer */
***************
*** 76,82 **** typedef FormData_pg_proc *Form_pg_proc;
* compiler constants for pg_proc
* ----------------
*/
! #define Natts_pg_proc 25
#define Anum_pg_proc_proname 1
#define Anum_pg_proc_pronamespace 2
#define Anum_pg_proc_proowner 3
--- 77,83 ----
* compiler constants for pg_proc
* ----------------
*/
! #define Natts_pg_proc 26
#define Anum_pg_proc_proname 1
#define Anum_pg_proc_pronamespace 2
#define Anum_pg_proc_proowner 3
***************
*** 84,107 **** typedef FormData_pg_proc *Form_pg_proc;
#define Anum_pg_proc_procost 5
#define Anum_pg_proc_prorows 6
#define Anum_pg_proc_provariadic 7
! #define Anum_pg_proc_proisagg 8
! #define Anum_pg_proc_proiswindow 9
! #define Anum_pg_proc_prosecdef 10
! #define Anum_pg_proc_proisstrict 11
! #define Anum_pg_proc_proretset 12
! #define Anum_pg_proc_provolatile 13
! #define Anum_pg_proc_pronargs 14
! #define Anum_pg_proc_pronargdefaults 15
! #define Anum_pg_proc_prorettype 16
! #define Anum_pg_proc_proargtypes 17
! #define Anum_pg_proc_proallargtypes 18
! #define Anum_pg_proc_proargmodes 19
! #define Anum_pg_proc_proargnames 20
! #define Anum_pg_proc_proargdefaults 21
! #define Anum_pg_proc_prosrc 22
! #define Anum_pg_proc_probin 23
! #define Anum_pg_proc_proconfig 24
! #define Anum_pg_proc_proacl 25
/* ----------------
* initial contents of pg_proc
--- 85,109 ----
#define Anum_pg_proc_procost 5
#define Anum_pg_proc_prorows 6
#define Anum_pg_proc_provariadic 7
! #define Anum_pg_proc_protransform 8
! #define Anum_pg_proc_proisagg 9
! #define Anum_pg_proc_proiswindow 10
! #define Anum_pg_proc_prosecdef 11
! #define Anum_pg_proc_proisstrict 12
! #define Anum_pg_proc_proretset 13
! #define Anum_pg_proc_provolatile 14
! #define Anum_pg_proc_pronargs 15
! #define Anum_pg_proc_pronargdefaults 16
! #define Anum_pg_proc_prorettype 17
! #define Anum_pg_proc_proargtypes 18
! #define Anum_pg_proc_proallargtypes 19
! #define Anum_pg_proc_proargmodes 20
! #define Anum_pg_proc_proargnames 21
! #define Anum_pg_proc_proargdefaults 22
! #define Anum_pg_proc_prosrc 23
! #define Anum_pg_proc_probin 24
! #define Anum_pg_proc_proconfig 25
! #define Anum_pg_proc_proacl 26
/* ----------------
* initial contents of pg_proc
***************
*** 743,749 **** DATA(insert OID = 659 ( namene
PGNSP PGUID 12 1 0 0 0 f f f t f i 2 0 16 "
DATA(insert OID = 668 ( bpchar PGNSP PGUID 12 1 0 0
0 f f f t f i 3 0 1042 "1042 23 16" _null_ _null_ _null_ _null_ bpchar _null_
_null_ _null_ ));
DESCR("adjust char() to typmod length");
! DATA(insert OID = 669 ( varchar PGNSP PGUID 12 1 0 0 0 f f f
t f i 3 0 1043 "1043 23 16" _null_ _null_ _null_ _null_ varchar _null_ _null_
_null_ ));
DESCR("adjust varchar() to typmod length");
DATA(insert OID = 676 ( mktinterval PGNSP PGUID 12 1 0 0 0 f f f t f i 2
0 704 "702 702" _null_ _null_ _null_ _null_ mktinterval _null_ _null_ _null_ ));
--- 745,753 ----
DATA(insert OID = 668 ( bpchar PGNSP PGUID 12 1 0 0
0 f f f t f i 3 0 1042 "1042 23 16" _null_ _null_ _null_ _null_ bpchar _null_
_null_ _null_ ));
DESCR("adjust char() to typmod length");
! DATA(insert OID = 3097 ( varchar_transform PGNSP PGUID 12 1 0 0 0 f f f t f i
1 0 2281 "2281" _null_ _null_ _null_ _null_ varchar_transform _null_ _null_
_null_ ));
! DESCR("transform a varchar length coercion");
! DATA(insert OID = 669 ( varchar PGNSP PGUID 12 1 0 0 3097 f
f f t f i 3 0 1043 "1043 23 16" _null_ _null_ _null_ _null_ varchar _null_
_null_ _null_ ));
DESCR("adjust varchar() to typmod length");
DATA(insert OID = 676 ( mktinterval PGNSP PGUID 12 1 0 0 0 f f f t f i 2
0 704 "702 702" _null_ _null_ _null_ _null_ mktinterval _null_ _null_ _null_ ));
diff --git a/src/include/parser/parsindex 09ef450..f5ce2ff 100644
*** a/src/include/parser/parse_clause.h
--- b/src/include/parser/parse_clause.h
***************
*** 44,47 **** extern List *transformDistinctOnClause(ParseState *pstate, List
*distinctlist,
--- 44,49 ----
extern Index assignSortGroupRef(TargetEntry *tle, List *tlist);
extern bool targetIsInSortList(TargetEntry *tle, Oid sortop, List *sortList);
+ extern Node *relabel_to_typmod(Node *expr, int32 typmod);
+
#endif /* PARSE_CLAUSE_H */
diff --git a/src/include/utils/builtins.index 14215db..8a1c82e 100644
*** a/src/include/utils/builtins.h
--- b/src/include/utils/builtins.h
***************
*** 684,689 **** extern Datum varcharrecv(PG_FUNCTION_ARGS);
--- 684,690 ----
extern Datum varcharsend(PG_FUNCTION_ARGS);
extern Datum varchartypmodin(PG_FUNCTION_ARGS);
extern Datum varchartypmodout(PG_FUNCTION_ARGS);
+ extern Datum varchar_transform(PG_FUNCTION_ARGS);
extern Datum varchar(PG_FUNCTION_ARGS);
/* varlena.c */
diff --git a/src/test/regress/expecindex 3326f93..1b5a878 100644
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