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Make parser rely more heavily on the ParseNamespaceItem data structure.

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When I added the ParseNamespaceItem data structure (in commit 5ebaaa494),
it wasn't very tightly integrated into the parser's APIs.  In the wake of
adding p_rtindex to that struct (commit b541e9acc), there is a good reason
to make more use of it: by passing around ParseNamespaceItem pointers
instead of bare RTE pointers, we can get rid of various messy methods for
passing back or deducing the rangetable index of an RTE during parsing.
Hence, refactor the addRangeTableEntryXXX functions to build and return
a ParseNamespaceItem struct, not just the RTE proper; and replace
addRTEtoQuery with addNSItemToQuery, which is passed a ParseNamespaceItem
rather than building one internally.

Also, add per-column data (a ParseNamespaceColumn array) to each
ParseNamespaceItem.  These arrays are built during addRangeTableEntryXXX,
where we have column type data at hand so that it's nearly free to fill
the data structure.  Later, when we need to build Vars referencing RTEs,
we can use the ParseNamespaceColumn info to avoid the rather expensive
operations done in get_rte_attribute_type() or expandRTE().
get_rte_attribute_type() is indeed dead code now, so I've removed it.
This makes for a useful improvement in parse analysis speed, around 20%
in one moderately-complex test query.

The ParseNamespaceColumn structs also include Var identity information
(varno/varattno).  That info isn't actually being used in this patch,
except that p_varno == 0 is a handy test for a dropped column.
A follow-on patch will make more use of it.

Discussion: https://postgr.es/m/2461.1577764221@sss.pgh.pa.us
This commit is contained in:
Tom Lane
2020-01-02 11:29:01 -05:00
parent 198c7153dc
commit 5815696bc6
20 changed files with 923 additions and 790 deletions
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139
src/backend/parser/analyze.c
View File

@@ -415,9 +415,7 @@ transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt)
stmt->relation->inh,
true,
ACL_DELETE);
/* grab the namespace item made by setTargetTable */
nsitem = (ParseNamespaceItem *) llast(pstate->p_namespace);
nsitem = pstate->p_target_nsitem;
/* there's no DISTINCT in DELETE */
qry->distinctClause = NIL;
@@ -476,8 +474,8 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
List *sub_namespace;
List *icolumns;
List *attrnos;
ParseNamespaceItem *nsitem;
RangeTblEntry *rte;
RangeTblRef *rtr;
ListCell *icols;
ListCell *attnos;
ListCell *lc;
@@ -611,18 +609,14 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
/*
* Make the source be a subquery in the INSERT's rangetable, and add
* it to the INSERT's joinlist.
* it to the INSERT's joinlist (but not the namespace).
*/
rte = addRangeTableEntryForSubquery(pstate,
selectQuery,
makeAlias("*SELECT*", NIL),
false,
false);
rtr = makeNode(RangeTblRef);
/* assume new rte is at end */
rtr->rtindex = list_length(pstate->p_rtable);
Assert(rte == rt_fetch(rtr->rtindex, pstate->p_rtable));
pstate->p_joinlist = lappend(pstate->p_joinlist, rtr);
nsitem = addRangeTableEntryForSubquery(pstate,
selectQuery,
makeAlias("*SELECT*", NIL),
false,
false);
addNSItemToQuery(pstate, nsitem, true, false, false);
/*----------
* Generate an expression list for the INSERT that selects all the
@@ -652,7 +646,7 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
expr = tle->expr;
else
{
Var *var = makeVarFromTargetEntry(rtr->rtindex, tle);
Var *var = makeVarFromTargetEntry(nsitem->p_rtindex, tle);
var->location = exprLocation((Node *) tle->expr);
expr = (Expr *) var;
@@ -774,19 +768,15 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
/*
* Generate the VALUES RTE
*/
rte = addRangeTableEntryForValues(pstate, exprsLists,
coltypes, coltypmods, colcollations,
NULL, lateral, true);
rtr = makeNode(RangeTblRef);
/* assume new rte is at end */
rtr->rtindex = list_length(pstate->p_rtable);
Assert(rte == rt_fetch(rtr->rtindex, pstate->p_rtable));
pstate->p_joinlist = lappend(pstate->p_joinlist, rtr);
nsitem = addRangeTableEntryForValues(pstate, exprsLists,
coltypes, coltypmods, colcollations,
NULL, lateral, true);
addNSItemToQuery(pstate, nsitem, true, false, false);
/*
* Generate list of Vars referencing the RTE
*/
expandRTE(rte, rtr->rtindex, 0, -1, false, NULL, &exprList);
exprList = expandNSItemVars(nsitem, 0, -1, NULL);
/*
* Re-apply any indirection on the target column specs to the Vars
@@ -829,7 +819,7 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
* Generate query's target list using the computed list of expressions.
* Also, mark all the target columns as needing insert permissions.
*/
rte = pstate->p_target_rangetblentry;
rte = pstate->p_target_nsitem->p_rte;
qry->targetList = NIL;
Assert(list_length(exprList) <= list_length(icolumns));
forthree(lc, exprList, icols, icolumns, attnos, attrnos)
@@ -863,8 +853,8 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
if (stmt->returningList)
{
pstate->p_namespace = NIL;
addRTEtoQuery(pstate, pstate->p_target_rangetblentry,
false, true, true);
addNSItemToQuery(pstate, pstate->p_target_nsitem,
false, true, true);
qry->returningList = transformReturningList(pstate,
stmt->returningList);
}
@@ -999,7 +989,6 @@ transformOnConflictClause(ParseState *pstate,
Oid arbiterConstraint;
List *onConflictSet = NIL;
Node *onConflictWhere = NULL;
RangeTblEntry *exclRte = NULL;
int exclRelIndex = 0;
List *exclRelTlist = NIL;
OnConflictExpr *result;
@@ -1012,6 +1001,8 @@ transformOnConflictClause(ParseState *pstate,
if (onConflictClause->action == ONCONFLICT_UPDATE)
{
Relation targetrel = pstate->p_target_relation;
ParseNamespaceItem *exclNSItem;
RangeTblEntry *exclRte;
/*
* All INSERT expressions have been parsed, get ready for potentially
@@ -1025,17 +1016,18 @@ transformOnConflictClause(ParseState *pstate,
* relation, and no permission checks are required on it. (We'll
* check the actual target relation, instead.)
*/
exclRte = addRangeTableEntryForRelation(pstate,
targetrel,
RowExclusiveLock,
makeAlias("excluded", NIL),
false, false);
exclNSItem = addRangeTableEntryForRelation(pstate,
targetrel,
RowExclusiveLock,
makeAlias("excluded", NIL),
false, false);
exclRte = exclNSItem->p_rte;
exclRelIndex = exclNSItem->p_rtindex;
exclRte->relkind = RELKIND_COMPOSITE_TYPE;
exclRte->requiredPerms = 0;
/* other permissions fields in exclRte are already empty */
exclRelIndex = list_length(pstate->p_rtable);
/* Create EXCLUDED rel's targetlist for use by EXPLAIN */
exclRelTlist = BuildOnConflictExcludedTargetlist(targetrel,
exclRelIndex);
@@ -1044,9 +1036,9 @@ transformOnConflictClause(ParseState *pstate,
* Add EXCLUDED and the target RTE to the namespace, so that they can
* be used in the UPDATE subexpressions.
*/
addRTEtoQuery(pstate, exclRte, false, true, true);
addRTEtoQuery(pstate, pstate->p_target_rangetblentry,
false, true, true);
addNSItemToQuery(pstate, exclNSItem, false, true, true);
addNSItemToQuery(pstate, pstate->p_target_nsitem,
false, true, true);
/*
* Now transform the UPDATE subexpressions.
@@ -1343,7 +1335,6 @@ transformValuesClause(ParseState *pstate, SelectStmt *stmt)
List **colexprs = NULL;
int sublist_length = -1;
bool lateral = false;
RangeTblEntry *rte;
ParseNamespaceItem *nsitem;
ListCell *lc;
ListCell *lc2;
@@ -1511,14 +1502,10 @@ transformValuesClause(ParseState *pstate, SelectStmt *stmt)
/*
* Generate the VALUES RTE
*/
rte = addRangeTableEntryForValues(pstate, exprsLists,
coltypes, coltypmods, colcollations,
NULL, lateral, true);
addRTEtoQuery(pstate, rte, true, true, true);
/* grab the namespace item made by addRTEtoQuery */
nsitem = (ParseNamespaceItem *) llast(pstate->p_namespace);
Assert(rte == nsitem->p_rte);
nsitem = addRangeTableEntryForValues(pstate, exprsLists,
coltypes, coltypmods, colcollations,
NULL, lateral, true);
addNSItemToQuery(pstate, nsitem, true, true, true);
/*
* Generate a targetlist as though expanding "*"
@@ -1593,7 +1580,9 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
*targetnames,
*sv_namespace;
int sv_rtable_length;
RangeTblEntry *jrte;
ParseNamespaceItem *jnsitem;
ParseNamespaceColumn *sortnscolumns;
int sortcolindex;
int tllen;
qry->commandType = CMD_SELECT;
@@ -1686,6 +1675,9 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
qry->targetList = NIL;
targetvars = NIL;
targetnames = NIL;
sortnscolumns = (ParseNamespaceColumn *)
palloc0(list_length(sostmt->colTypes) * sizeof(ParseNamespaceColumn));
sortcolindex = 0;
forfour(lct, sostmt->colTypes,
lcm, sostmt->colTypmods,
@@ -1716,6 +1708,14 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
qry->targetList = lappend(qry->targetList, tle);
targetvars = lappend(targetvars, var);
targetnames = lappend(targetnames, makeString(colName));
sortnscolumns[sortcolindex].p_varno = leftmostRTI;
sortnscolumns[sortcolindex].p_varattno = lefttle->resno;
sortnscolumns[sortcolindex].p_vartype = colType;
sortnscolumns[sortcolindex].p_vartypmod = colTypmod;
sortnscolumns[sortcolindex].p_varcollid = colCollation;
sortnscolumns[sortcolindex].p_varnosyn = leftmostRTI;
sortnscolumns[sortcolindex].p_varattnosyn = lefttle->resno;
sortcolindex++;
}
/*
@@ -1730,18 +1730,19 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
*/
sv_rtable_length = list_length(pstate->p_rtable);
jrte = addRangeTableEntryForJoin(pstate,
targetnames,
JOIN_INNER,
targetvars,
NULL,
false);
jnsitem = addRangeTableEntryForJoin(pstate,
targetnames,
sortnscolumns,
JOIN_INNER,
targetvars,
NULL,
false);
sv_namespace = pstate->p_namespace;
pstate->p_namespace = NIL;
/* add jrte to column namespace only */
addRTEtoQuery(pstate, jrte, false, false, true);
/* add jnsitem to column namespace only */
addNSItemToQuery(pstate, jnsitem, false, false, true);
/*
* For now, we don't support resjunk sort clauses on the output of a
@@ -1757,7 +1758,7 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
EXPR_KIND_ORDER_BY,
false /* allow SQL92 rules */ );
/* restore namespace, remove jrte from rtable */
/* restore namespace, remove join RTE from rtable */
pstate->p_namespace = sv_namespace;
pstate->p_rtable = list_truncate(pstate->p_rtable, sv_rtable_length);
@@ -1869,7 +1870,7 @@ transformSetOperationTree(ParseState *pstate, SelectStmt *stmt,
/* Process leaf SELECT */
Query *selectQuery;
char selectName[32];
RangeTblEntry *rte PG_USED_FOR_ASSERTS_ONLY;
ParseNamespaceItem *nsitem;
RangeTblRef *rtr;
ListCell *tl;
@@ -1926,19 +1927,17 @@ transformSetOperationTree(ParseState *pstate, SelectStmt *stmt,
*/
snprintf(selectName, sizeof(selectName), "*SELECT* %d",
list_length(pstate->p_rtable) + 1);
rte = addRangeTableEntryForSubquery(pstate,
selectQuery,
makeAlias(selectName, NIL),
false,
false);
nsitem = addRangeTableEntryForSubquery(pstate,
selectQuery,
makeAlias(selectName, NIL),
false,
false);
/*
* Return a RangeTblRef to replace the SelectStmt in the set-op tree.
*/
rtr = makeNode(RangeTblRef);
/* assume new rte is at end */
rtr->rtindex = list_length(pstate->p_rtable);
Assert(rte == rt_fetch(rtr->rtindex, pstate->p_rtable));
rtr->rtindex = nsitem->p_rtindex;
return (Node *) rtr;
}
else
@@ -2236,9 +2235,7 @@ transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt)
stmt->relation->inh,
true,
ACL_UPDATE);
/* grab the namespace item made by setTargetTable */
nsitem = (ParseNamespaceItem *) llast(pstate->p_namespace);
nsitem = pstate->p_target_nsitem;
/* subqueries in FROM cannot access the result relation */
nsitem->p_lateral_only = true;
@@ -2297,7 +2294,7 @@ transformUpdateTargetList(ParseState *pstate, List *origTlist)
pstate->p_next_resno = RelationGetNumberOfAttributes(pstate->p_target_relation) + 1;
/* Prepare non-junk columns for assignment to target table */
target_rte = pstate->p_target_rangetblentry;
target_rte = pstate->p_target_nsitem->p_rte;
orig_tl = list_head(origTlist);
foreach(tl, tlist)