@ -274,6 +274,8 @@ build_base_rel_tlists(PlannerInfo *root, List *final_tlist)
* have a single owning relation ; we keep their attr_needed info in
* root - > placeholder_list instead . Find or create the associated
* PlaceHolderInfo entry , and update its ph_needed .
*
* See also add_vars_to_attr_needed .
*/
void
add_vars_to_targetlist ( PlannerInfo * root , List * vars ,
@ -327,6 +329,63 @@ add_vars_to_targetlist(PlannerInfo *root, List *vars,
}
}
/*
* add_vars_to_attr_needed
* This does a subset of what add_vars_to_targetlist does : it just
* updates attr_needed for Vars and ph_needed for PlaceHolderVars .
* We assume the Vars are already in their relations ' targetlists .
*
* This is used to rebuild attr_needed / ph_needed sets after removal
* of a useless outer join . The removed join clause might have been
* the only upper - level use of some other relation ' s Var , in which
* case we can reduce that Var ' s attr_needed and thereby possibly
* open the door to further join removals . But we can ' t tell that
* without tedious reconstruction of the attr_needed data .
*
* Note that if a Var ' s attr_needed is successfully reduced to empty ,
* it will still be in the relation ' s targetlist even though we do
* not really need the scan plan node to emit it . The extra plan
* inefficiency seems tiny enough to not be worth spending planner
* cycles to get rid of it .
*/
void
add_vars_to_attr_needed ( PlannerInfo * root , List * vars ,
Relids where_needed )
{
ListCell * temp ;
Assert ( ! bms_is_empty ( where_needed ) ) ;
foreach ( temp , vars )
{
Node * node = ( Node * ) lfirst ( temp ) ;
if ( IsA ( node , Var ) )
{
Var * var = ( Var * ) node ;
RelOptInfo * rel = find_base_rel ( root , var - > varno ) ;
int attno = var - > varattno ;
if ( bms_is_subset ( where_needed , rel - > relids ) )
continue ;
Assert ( attno > = rel - > min_attr & & attno < = rel - > max_attr ) ;
attno - = rel - > min_attr ;
rel - > attr_needed [ attno ] = bms_add_members ( rel - > attr_needed [ attno ] ,
where_needed ) ;
}
else if ( IsA ( node , PlaceHolderVar ) )
{
PlaceHolderVar * phv = ( PlaceHolderVar * ) node ;
PlaceHolderInfo * phinfo = find_placeholder_info ( root , phv ) ;
phinfo - > ph_needed = bms_add_members ( phinfo - > ph_needed ,
where_needed ) ;
}
else
elog ( ERROR , " unrecognized node type: %d " , ( int ) nodeTag ( node ) ) ;
}
}
/*****************************************************************************
*
@ -488,10 +547,54 @@ extract_lateral_references(PlannerInfo *root, RelOptInfo *brel, Index rtindex)
*/
add_vars_to_targetlist ( root , newvars , where_needed ) ;
/* Remember the lateral references for create_lateral_join_info */
/*
* Remember the lateral references for rebuild_lateral_attr_needed and
* create_lateral_join_info .
*/
brel - > lateral_vars = newvars ;
}
/*
* rebuild_lateral_attr_needed
* Put back attr_needed bits for Vars / PHVs needed for lateral references .
*
* This is used to rebuild attr_needed / ph_needed sets after removal of a
* useless outer join . It should match what find_lateral_references did ,
* except that we call add_vars_to_attr_needed not add_vars_to_targetlist .
*/
void
rebuild_lateral_attr_needed ( PlannerInfo * root )
{
Index rti ;
/* We need do nothing if the query contains no LATERAL RTEs */
if ( ! root - > hasLateralRTEs )
return ;
/* Examine the same baserels that find_lateral_references did */
for ( rti = 1 ; rti < root - > simple_rel_array_size ; rti + + )
{
RelOptInfo * brel = root - > simple_rel_array [ rti ] ;
Relids where_needed ;
if ( brel = = NULL )
continue ;
if ( brel - > reloptkind ! = RELOPT_BASEREL )
continue ;
/*
* We don ' t need to repeat all of extract_lateral_references , since it
* kindly saved the extracted Vars / PHVs in lateral_vars .
*/
if ( brel - > lateral_vars = = NIL )
continue ;
where_needed = bms_make_singleton ( rti ) ;
add_vars_to_attr_needed ( root , brel - > lateral_vars , where_needed ) ;
}
}
/*
* create_lateral_join_info
* Fill in the per - base - relation direct_lateral_relids , lateral_relids
@ -2445,6 +2548,9 @@ distribute_qual_to_rels(PlannerInfo *root, Node *clause,
* var propagation is ensured by making ojscope include input rels from
* both sides of the join .
*
* See also rebuild_joinclause_attr_needed , which has to partially repeat
* this work after removal of an outer join .
*
* Note : if the clause gets absorbed into an EquivalenceClass then this
* may be unnecessary , but for now we have to do it to cover the case
* where the EC becomes ec_broken and we end up reinserting the original
@ -3014,6 +3120,11 @@ process_implied_equality(PlannerInfo *root,
* some of the Vars could have missed having that done because they only
* appeared in single - relation clauses originally . So do it here for
* safety .
*
* See also rebuild_joinclause_attr_needed , which has to partially repeat
* this work after removal of an outer join . ( Since we will put this
* clause into the joininfo lists , that function needn ' t do any extra work
* to find it . )
*/
if ( bms_membership ( relids ) = = BMS_MULTIPLE )
{
@ -3155,6 +3266,72 @@ get_join_domain_min_rels(PlannerInfo *root, Relids domain_relids)
}
/*
* rebuild_joinclause_attr_needed
* Put back attr_needed bits for Vars / PHVs needed for join clauses .
*
* This is used to rebuild attr_needed / ph_needed sets after removal of a
* useless outer join . It should match what distribute_qual_to_rels did ,
* except that we call add_vars_to_attr_needed not add_vars_to_targetlist .
*/
void
rebuild_joinclause_attr_needed ( PlannerInfo * root )
{
/*
* We must examine all join clauses , but there ' s no value in processing
* any join clause more than once . So it ' s slightly annoying that we have
* to find them via the per - base - relation joininfo lists . Avoid duplicate
* processing by tracking the rinfo_serial numbers of join clauses we ' ve
* already seen . ( This doesn ' t work for is_clone clauses , so we must
* waste effort on them . )
*/
Bitmapset * seen_serials = NULL ;
Index rti ;
/* Scan all baserels for join clauses */
for ( rti = 1 ; rti < root - > simple_rel_array_size ; rti + + )
{
RelOptInfo * brel = root - > simple_rel_array [ rti ] ;
ListCell * lc ;
if ( brel = = NULL )
continue ;
if ( brel - > reloptkind ! = RELOPT_BASEREL )
continue ;
foreach ( lc , brel - > joininfo )
{
RestrictInfo * rinfo = ( RestrictInfo * ) lfirst ( lc ) ;
Relids relids = rinfo - > required_relids ;
if ( ! rinfo - > is_clone ) /* else serial number is not unique */
{
if ( bms_is_member ( rinfo - > rinfo_serial , seen_serials ) )
continue ; /* saw it already */
seen_serials = bms_add_member ( seen_serials ,
rinfo - > rinfo_serial ) ;
}
if ( bms_membership ( relids ) = = BMS_MULTIPLE )
{
List * vars = pull_var_clause ( ( Node * ) rinfo - > clause ,
PVC_RECURSE_AGGREGATES |
PVC_RECURSE_WINDOWFUNCS |
PVC_INCLUDE_PLACEHOLDERS ) ;
Relids where_needed ;
if ( rinfo - > is_clone )
where_needed = bms_intersect ( relids , root - > all_baserels ) ;
else
where_needed = relids ;
add_vars_to_attr_needed ( root , vars , where_needed ) ;
list_free ( vars ) ;
}
}
}
}
/*
* match_foreign_keys_to_quals
* Match foreign - key constraints to equivalence classes and join quals
Tom Lane
12 months ago