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Remove arbitrary 64K-or-so limit on rangetable size. 

Up to now the size of a query's rangetable has been limited by the
constants INNER_VAR et al, which mustn't be equal to any real
rangetable index.  65000 doubtless seemed like enough for anybody,
and it still is orders of magnitude larger than the number of joins
we can realistically handle.  However, we need a rangetable entry
for each child partition that is (or might be) processed by a query.
Queries with a few thousand partitions are getting more realistic,
so that the day when that limit becomes a problem is in sight,
even if it's not here yet.  Hence, let's raise the limit.

Rather than just increase the values of INNER_VAR et al, this patch
adopts the approach of making them small negative values, so that
rangetables could theoretically become as long as INT_MAX.

The bulk of the patch is concerned with changing Var.varno and some
related variables from "Index" (unsigned int) to plain "int".  This
is basically cosmetic, with little actual effect other than to help
debuggers print their values nicely.  As such, I've only bothered
with changing places that could actually see INNER_VAR et al, which
the parser and most of the planner don't.  We do have to be careful
in places that are performing less/greater comparisons on varnos,
but there are very few such places, other than the IS_SPECIAL_VARNO
macro itself.

A notable side effect of this patch is that while it used to be
possible to add INNER_VAR et al to a Bitmapset, that will now
draw an error.  I don't see any likelihood that it wouldn't be a
bug to include these fake varnos in a bitmapset of real varnos,
so I think this is all to the good.

Although this touches outfuncs/readfuncs, I don't think a catversion
bump is required, since stored rules would never contain Vars
with these fake varnos.

Andrey Lepikhov and Tom Lane, after a suggestion by Peter Eisentraut

Discussion: https://postgr.es/m/43c7f2f5-1e27-27aa-8c65-c91859d15190@postgrespro.ru
This commit is contained in:
Tom Lane 2021-09-15 14:11:21 -04:00
parent 6fe0eb963d
commit e3ec3c00d8
15 changed files with 48 additions and 57 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
src/backend/executor/execScan.c
View File

@ -282,7 +282,7 @@ ExecAssignScanProjectionInfo(ScanState *node)
* As above, but caller can specify varno expected in Vars in the tlist.
*/
void
ExecAssignScanProjectionInfoWithVarno(ScanState *node, Index varno)
ExecAssignScanProjectionInfoWithVarno(ScanState *node, int varno)
{
TupleDesc tupdesc = node->ss_ScanTupleSlot->tts_tupleDescriptor;

6
src/backend/executor/execUtils.c
View File

@ -65,7 +65,7 @@
#include "utils/typcache.h"
static bool tlist_matches_tupdesc(PlanState *ps, List *tlist, Index varno, TupleDesc tupdesc);
static bool tlist_matches_tupdesc(PlanState *ps, List *tlist, int varno, TupleDesc tupdesc);
static void ShutdownExprContext(ExprContext *econtext, bool isCommit);
@ -553,7 +553,7 @@ ExecAssignProjectionInfo(PlanState *planstate,
*/
void
ExecConditionalAssignProjectionInfo(PlanState *planstate, TupleDesc inputDesc,
Index varno)
int varno)
{
if (tlist_matches_tupdesc(planstate,
planstate->plan->targetlist,
@ -579,7 +579,7 @@ ExecConditionalAssignProjectionInfo(PlanState *planstate, TupleDesc inputDesc,
}
static bool
tlist_matches_tupdesc(PlanState *ps, List *tlist, Index varno, TupleDesc tupdesc)
tlist_matches_tupdesc(PlanState *ps, List *tlist, int varno, TupleDesc tupdesc)
{
int numattrs = tupdesc->natts;
int attrno;

2
src/backend/executor/nodeCustom.c
View File

@ -31,7 +31,7 @@ ExecInitCustomScan(CustomScan *cscan, EState *estate, int eflags)
CustomScanState *css;
Relation scan_rel = NULL;
Index scanrelid = cscan->scan.scanrelid;
Index tlistvarno;
int tlistvarno;
/*
* Allocate the CustomScanState object. We let the custom scan provider

2
src/backend/executor/nodeForeignscan.c
View File

@ -138,7 +138,7 @@ ExecInitForeignScan(ForeignScan *node, EState *estate, int eflags)
ForeignScanState *scanstate;
Relation currentRelation = NULL;
Index scanrelid = node->scan.scanrelid;
Index tlistvarno;
int tlistvarno;
FdwRoutine *fdwroutine;
/* check for unsupported flags */

8
src/backend/nodes/makefuncs.c
View File

@ -63,7 +63,7 @@ makeSimpleA_Expr(A_Expr_Kind kind, char *name,
* creates a Var node
*/
Var *
makeVar(Index varno,
makeVar(int varno,
AttrNumber varattno,
Oid vartype,
int32 vartypmod,
@ -85,7 +85,7 @@ makeVar(Index varno,
* them, but just initialize them to the given varno/varattno. This
* reduces code clutter and chance of error for most callers.
*/
var->varnosyn = varno;
var->varnosyn = (Index) varno;
var->varattnosyn = varattno;
/* Likewise, we just set location to "unknown" here */
@ -100,7 +100,7 @@ makeVar(Index varno,
* TargetEntry
*/
Var *
makeVarFromTargetEntry(Index varno,
makeVarFromTargetEntry(int varno,
TargetEntry *tle)
{
return makeVar(varno,
@ -131,7 +131,7 @@ makeVarFromTargetEntry(Index varno,
*/
Var *
makeWholeRowVar(RangeTblEntry *rte,
Index varno,
int varno,
Index varlevelsup,
bool allowScalar)
{

2
src/backend/nodes/outfuncs.c
View File

@ -1123,7 +1123,7 @@ _outVar(StringInfo str, const Var *node)
{
WRITE_NODE_TYPE("VAR");
WRITE_UINT_FIELD(varno);
WRITE_INT_FIELD(varno);
WRITE_INT_FIELD(varattno);
WRITE_OID_FIELD(vartype);
WRITE_INT_FIELD(vartypmod);

2
src/backend/nodes/readfuncs.c
View File

@ -577,7 +577,7 @@ _readVar(void)
{
READ_LOCALS(Var);
READ_UINT_FIELD(varno);
READ_INT_FIELD(varno);
READ_INT_FIELD(varattno);
READ_OID_FIELD(vartype);
READ_INT_FIELD(vartypmod);

3
src/backend/optimizer/path/costsize.c
View File

@ -5961,7 +5961,8 @@ set_pathtarget_cost_width(PlannerInfo *root, PathTarget *target)
Assert(var->varlevelsup == 0);
/* Try to get data from RelOptInfo cache */
if (var->varno < root->simple_rel_array_size)
if (!IS_SPECIAL_VARNO(var->varno) &&
var->varno < root->simple_rel_array_size)
{
RelOptInfo *rel = root->simple_rel_array[var->varno];

3
src/backend/optimizer/plan/createplan.c
View File

@ -4805,7 +4805,8 @@ replace_nestloop_params_mutator(Node *node, PlannerInfo *root)
/* Upper-level Vars should be long gone at this point */
Assert(var->varlevelsup == 0);
/* If not to be replaced, we can just return the Var unmodified */
if (!bms_is_member(var->varno, root->curOuterRels))
if (IS_SPECIAL_VARNO(var->varno) ||
!bms_is_member(var->varno, root->curOuterRels))
return node;
/* Replace the Var with a nestloop Param */
return (Node *) replace_nestloop_param_var(root, var);

40
src/backend/optimizer/plan/setrefs.c
View File

@ -31,7 +31,7 @@
typedef struct
{
Index varno; /* RT index of Var */
int varno; /* RT index of Var */
AttrNumber varattno; /* attr number of Var */
AttrNumber resno; /* TLE position of Var */
} tlist_vinfo;
@ -66,7 +66,7 @@ typedef struct
{
PlannerInfo *root;
indexed_tlist *subplan_itlist;
Index newvarno;
int newvarno;
int rtoffset;
double num_exec;
} fix_upper_expr_context;
@ -143,15 +143,15 @@ static void set_dummy_tlist_references(Plan *plan, int rtoffset);
static indexed_tlist *build_tlist_index(List *tlist);
static Var *search_indexed_tlist_for_var(Var *var,
indexed_tlist *itlist,
Index newvarno,
int newvarno,
int rtoffset);
static Var *search_indexed_tlist_for_non_var(Expr *node,
indexed_tlist *itlist,
Index newvarno);
int newvarno);
static Var *search_indexed_tlist_for_sortgroupref(Expr *node,
Index sortgroupref,
indexed_tlist *itlist,
Index newvarno);
int newvarno);
static List *fix_join_expr(PlannerInfo *root,
List *clauses,
indexed_tlist *outer_itlist,
@ -163,7 +163,7 @@ static Node *fix_join_expr_mutator(Node *node,
static Node *fix_upper_expr(PlannerInfo *root,
Node *node,
indexed_tlist *subplan_itlist,
Index newvarno,
int newvarno,
int rtoffset, double num_exec);
static Node *fix_upper_expr_mutator(Node *node,
fix_upper_expr_context *context);
@ -505,16 +505,6 @@ add_rte_to_flat_rtable(PlannerGlobal *glob, RangeTblEntry *rte)
glob->finalrtable = lappend(glob->finalrtable, newrte);
/*
* Check for RT index overflow; it's very unlikely, but if it did happen,
* the executor would get confused by varnos that match the special varno
* values.
*/
if (IS_SPECIAL_VARNO(list_length(glob->finalrtable)))
ereport(ERROR,
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
errmsg("too many range table entries")));
/*
* If it's a plain relation RTE, add the table to relationOids.
*
@ -1947,10 +1937,8 @@ fix_scan_expr_mutator(Node *node, fix_scan_expr_context *context)
{
CurrentOfExpr *cexpr = (CurrentOfExpr *) copyObject(node);
Assert(cexpr->cvarno != INNER_VAR);
Assert(cexpr->cvarno != OUTER_VAR);
if (!IS_SPECIAL_VARNO(cexpr->cvarno))
cexpr->cvarno += context->rtoffset;
Assert(!IS_SPECIAL_VARNO(cexpr->cvarno));
cexpr->cvarno += context->rtoffset;
return (Node *) cexpr;
}
if (IsA(node, PlaceHolderVar))
@ -2447,7 +2435,7 @@ build_tlist_index(List *tlist)
* (so nothing other than Vars and PlaceHolderVars can be matched).
*/
static indexed_tlist *
build_tlist_index_other_vars(List *tlist, Index ignore_rel)
build_tlist_index_other_vars(List *tlist, int ignore_rel)
{
indexed_tlist *itlist;
tlist_vinfo *vinfo;
@ -2499,9 +2487,9 @@ build_tlist_index_other_vars(List *tlist, Index ignore_rel)
*/
static Var *
search_indexed_tlist_for_var(Var *var, indexed_tlist *itlist,
Index newvarno, int rtoffset)
int newvarno, int rtoffset)
{
Index varno = var->varno;
int varno = var->varno;
AttrNumber varattno = var->varattno;
tlist_vinfo *vinfo;
int i;
@ -2539,7 +2527,7 @@ search_indexed_tlist_for_var(Var *var, indexed_tlist *itlist,
*/
static Var *
search_indexed_tlist_for_non_var(Expr *node,
indexed_tlist *itlist, Index newvarno)
indexed_tlist *itlist, int newvarno)
{
TargetEntry *tle;
@ -2581,7 +2569,7 @@ static Var *
search_indexed_tlist_for_sortgroupref(Expr *node,
Index sortgroupref,
indexed_tlist *itlist,
Index newvarno)
int newvarno)
{
ListCell *lc;
@ -2799,7 +2787,7 @@ static Node *
fix_upper_expr(PlannerInfo *root,
Node *node,
indexed_tlist *subplan_itlist,
Index newvarno,
int newvarno,
int rtoffset,
double num_exec)
{

4
src/backend/optimizer/prep/prepjointree.c
View File

@ -80,7 +80,7 @@ static Node *pull_up_simple_union_all(PlannerInfo *root, Node *jtnode,
static void pull_up_union_leaf_queries(Node *setOp, PlannerInfo *root,
int parentRTindex, Query *setOpQuery,
int childRToffset);
static void make_setop_translation_list(Query *query, Index newvarno,
static void make_setop_translation_list(Query *query, int newvarno,
AppendRelInfo *appinfo);
static bool is_simple_subquery(PlannerInfo *root, Query *subquery,
RangeTblEntry *rte,
@ -1372,7 +1372,7 @@ pull_up_union_leaf_queries(Node *setOp, PlannerInfo *root, int parentRTindex,
* Also create the rather trivial reverse-translation array.
*/
static void
make_setop_translation_list(Query *query, Index newvarno,
make_setop_translation_list(Query *query, int newvarno,
AppendRelInfo *appinfo)
{
List *vars = NIL;

6
src/backend/utils/adt/ruleutils.c
View File

@ -6949,7 +6949,7 @@ get_variable(Var *var, int levelsup, bool istoplevel, deparse_context *context)
AttrNumber attnum;
int netlevelsup;
deparse_namespace *dpns;
Index varno;
int varno;
AttrNumber varattno;
deparse_columns *colinfo;
char *refname;
@ -6995,7 +6995,7 @@ get_variable(Var *var, int levelsup, bool istoplevel, deparse_context *context)
*/
if (context->appendparents && dpns->appendrels)
{
Index pvarno = varno;
int pvarno = varno;
AttrNumber pvarattno = varattno;
AppendRelInfo *appinfo = dpns->appendrels[pvarno];
bool found = false;
@ -7305,7 +7305,7 @@ get_name_for_var_field(Var *var, int fieldno,
AttrNumber attnum;
int netlevelsup;
deparse_namespace *dpns;
Index varno;
int varno;
AttrNumber varattno;
TupleDesc tupleDesc;
Node *expr;

4
src/include/executor/executor.h
View File

@ -459,7 +459,7 @@ typedef bool (*ExecScanRecheckMtd) (ScanState *node, TupleTableSlot *slot);
extern TupleTableSlot *ExecScan(ScanState *node, ExecScanAccessMtd accessMtd,
ExecScanRecheckMtd recheckMtd);
extern void ExecAssignScanProjectionInfo(ScanState *node);
extern void ExecAssignScanProjectionInfoWithVarno(ScanState *node, Index varno);
extern void ExecAssignScanProjectionInfoWithVarno(ScanState *node, int varno);
extern void ExecScanReScan(ScanState *node);
/*
@ -552,7 +552,7 @@ extern const TupleTableSlotOps *ExecGetResultSlotOps(PlanState *planstate,
extern void ExecAssignProjectionInfo(PlanState *planstate,
TupleDesc inputDesc);
extern void ExecConditionalAssignProjectionInfo(PlanState *planstate,
TupleDesc inputDesc, Index varno);
TupleDesc inputDesc, int varno);
extern void ExecFreeExprContext(PlanState *planstate);
extern void ExecAssignScanType(ScanState *scanstate, TupleDesc tupDesc);
extern void ExecCreateScanSlotFromOuterPlan(EState *estate,

6
src/include/nodes/makefuncs.h
View File

@ -24,18 +24,18 @@ extern A_Expr *makeA_Expr(A_Expr_Kind kind, List *name,
extern A_Expr *makeSimpleA_Expr(A_Expr_Kind kind, char *name,
Node *lexpr, Node *rexpr, int location);
extern Var *makeVar(Index varno,
extern Var *makeVar(int varno,
AttrNumber varattno,
Oid vartype,
int32 vartypmod,
Oid varcollid,
Index varlevelsup);
extern Var *makeVarFromTargetEntry(Index varno,
extern Var *makeVarFromTargetEntry(int varno,
TargetEntry *tle);
extern Var *makeWholeRowVar(RangeTblEntry *rte,
Index varno,
int varno,
Index varlevelsup,
bool allowScalar);

15
src/include/nodes/primnodes.h
View File

@ -172,12 +172,12 @@ typedef struct Expr
* in the planner and doesn't correspond to any simple relation column may
* have varnosyn = varattnosyn = 0.
*/
#define INNER_VAR 65000 /* reference to inner subplan */
#define OUTER_VAR 65001 /* reference to outer subplan */
#define INDEX_VAR 65002 /* reference to index column */
#define ROWID_VAR 65003 /* row identity column during planning */
#define INNER_VAR (-1) /* reference to inner subplan */
#define OUTER_VAR (-2) /* reference to outer subplan */
#define INDEX_VAR (-3) /* reference to index column */
#define ROWID_VAR (-4) /* row identity column during planning */
#define IS_SPECIAL_VARNO(varno) ((varno) >= INNER_VAR)
#define IS_SPECIAL_VARNO(varno) ((int) (varno) < 0)
/* Symbols for the indexes of the special RTE entries in rules */
#define PRS2_OLD_VARNO 1
@ -186,8 +186,8 @@ typedef struct Expr
typedef struct Var
{
Expr xpr;
Index varno; /* index of this var's relation in the range
* table, or INNER_VAR/OUTER_VAR/INDEX_VAR */
int varno; /* index of this var's relation in the range
* table, or INNER_VAR/OUTER_VAR/etc */
AttrNumber varattno; /* attribute number of this var, or zero for
* all attrs ("whole-row Var") */
Oid vartype; /* pg_type OID for the type of this var */
@ -1351,6 +1351,7 @@ typedef struct SetToDefault
* of the target relation being constrained; this aids placing the expression
* correctly during planning. We can assume however that its "levelsup" is
* always zero, due to the syntactic constraints on where it can appear.
* Also, cvarno will always be a true RT index, never INNER_VAR etc.
*
* The referenced cursor can be represented either as a hardwired string
* or as a reference to a run-time parameter of type REFCURSOR. The latter