diff options
Diffstat (limited to 'src/include/nodes/relation.h')
| -rw-r--r-- | src/include/nodes/relation.h | 44 |
1 files changed, 41 insertions, 3 deletions
diff --git a/src/include/nodes/relation.h b/src/include/nodes/relation.h index 8238981c289..43c2956fdf5 100644 --- a/src/include/nodes/relation.h +++ b/src/include/nodes/relation.h @@ -193,7 +193,9 @@ typedef struct PlannerInfo List *full_join_clauses; /* list of RestrictInfos for * mergejoinable full join clauses */ - List *join_info_list; /* list of SpecialJoinInfos */ + List *join_info_list; /* list of SpecialJoinInfos */ + + List *lateral_info_list; /* list of LateralJoinInfos */ List *append_rel_list; /* list of AppendRelInfos */ @@ -223,6 +225,7 @@ typedef struct PlannerInfo bool hasInheritedTarget; /* true if parse->resultRelation is an * inheritance child rel */ bool hasJoinRTEs; /* true if any RTEs are RTE_JOIN kind */ + bool hasLateralRTEs; /* true if any RTEs are marked LATERAL */ bool hasHavingQual; /* true if havingQual was non-null */ bool hasPseudoConstantQuals; /* true if any RestrictInfo has * pseudoconstant = true */ @@ -300,8 +303,8 @@ typedef struct PlannerInfo * we need to output from this relation. * List is in no particular order, but all rels of an * appendrel set must use corresponding orders. - * NOTE: in a child relation, may contain RowExpr or - * ConvertRowtypeExpr representing a whole-row Var. + * NOTE: in an appendrel child relation, may contain + * arbitrary expressions pulled up from a subquery! * pathlist - List of Path nodes, one for each potentially useful * method of generating the relation * ppilist - ParamPathInfo nodes for parameterized Paths, if any @@ -330,6 +333,10 @@ typedef struct PlannerInfo * the attribute is needed as part of final targetlist * attr_widths - cache space for per-attribute width estimates; * zero means not computed yet + * lateral_vars - lateral cross-references of rel, if any (list of + * Vars and PlaceHolderVars) + * lateral_relids - required outer rels for LATERAL, as a Relids set + * (for child rels this can be more than lateral_vars) * indexlist - list of IndexOptInfo nodes for relation's indexes * (always NIL if it's not a table) * pages - number of disk pages in relation (zero if not a table) @@ -417,6 +424,8 @@ typedef struct RelOptInfo AttrNumber max_attr; /* largest attrno of rel */ Relids *attr_needed; /* array indexed [min_attr .. max_attr] */ int32 *attr_widths; /* array indexed [min_attr .. max_attr] */ + List *lateral_vars; /* LATERAL Vars and PHVs referenced by rel */ + Relids lateral_relids; /* minimum parameterization of rel */ List *indexlist; /* list of IndexOptInfo */ BlockNumber pages; /* size estimates derived from pg_class */ double tuples; @@ -1324,6 +1333,35 @@ typedef struct SpecialJoinInfo } SpecialJoinInfo; /* + * "Lateral join" info. + * + * Lateral references in subqueries constrain the join order in a way that's + * somewhat like outer joins, though different in detail. We construct one or + * more LateralJoinInfos for each RTE with lateral references, and add them to + * the PlannerInfo node's lateral_info_list. + * + * lateral_rhs is the relid of a baserel with lateral references, and + * lateral_lhs is a set of relids of baserels it references, all of which + * must be present on the LHS to compute a parameter needed by the RHS. + * Typically, lateral_lhs is a singleton, but it can include multiple rels + * if the RHS references a PlaceHolderVar with a multi-rel ph_eval_at level. + * We disallow joining to only part of the LHS in such cases, since that would + * result in a join tree with no convenient place to compute the PHV. + * + * When an appendrel contains lateral references (eg "LATERAL (SELECT x.col1 + * UNION ALL SELECT y.col2)"), the LateralJoinInfos reference the parent + * baserel not the member otherrels, since it is the parent relid that is + * considered for joining purposes. + */ + +typedef struct LateralJoinInfo +{ + NodeTag type; + Index lateral_rhs; /* a baserel containing lateral refs */ + Relids lateral_lhs; /* some base relids it references */ +} LateralJoinInfo; + +/* * Append-relation info. * * When we expand an inheritable table or a UNION-ALL subselect into an |