| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| /*------------------------------------------------------------------------- |
| * |
| * relation.h |
| * Definitions for planner's internal data structures. |
| * |
| * |
| * Portions Copyright (c) 2005-2010, Greenplum inc |
| * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group |
| * Portions Copyright (c) 1994, Regents of the University of California |
| * |
| * $PostgreSQL: pgsql/src/include/nodes/relation.h,v 1.128.2.4 2007/08/31 01:44:14 tgl Exp $ |
| * |
| *------------------------------------------------------------------------- |
| */ |
| #ifndef RELATION_H |
| #define RELATION_H |
| |
| #include "access/sdir.h" |
| #include "nodes/bitmapset.h" |
| #include "nodes/params.h" |
| #include "nodes/parsenodes.h" |
| #include "nodes/plannodes.h" |
| #include "nodes/primnodes.h" |
| #include "executor/execdesc.h" |
| #include "storage/block.h" |
| #include "nodes/plannerconfig.h" |
| #include "cdb/cdbpathlocus.h" |
| |
| /* |
| * Relids |
| * Set of relation identifiers (indexes into the rangetable). |
| */ |
| typedef Bitmapset *Relids; |
| |
| /* |
| * Estimated costs |
| */ |
| typedef double EstimatedBytes; /* an estimated number of bytes */ |
| |
| /* |
| * When looking for a "cheapest path", this enum specifies whether we want |
| * cheapest startup cost or cheapest total cost. |
| */ |
| typedef enum CostSelector |
| { |
| STARTUP_COST, TOTAL_COST |
| } CostSelector; |
| |
| /* |
| * The cost estimate produced by cost_qual_eval() includes both a one-time |
| * (startup) cost, and a per-tuple cost. |
| */ |
| typedef struct QualCost |
| { |
| Cost startup; /* one-time cost */ |
| Cost per_tuple; /* per-evaluation cost */ |
| } QualCost; |
| |
| |
| /* |
| * Context for apply shareinput processing during planning. We could fold |
| * this into PlannerGlobal, but this encapsulates it nicely. |
| */ |
| typedef struct ApplyShareInputContext |
| { |
| List *sharedNodes; |
| List *sliceMarks; |
| List *motStack; |
| List *qdShares; |
| List *qdSlices; |
| List *planNodes; |
| int nextPlanId; |
| } ApplyShareInputContext; |
| |
| |
| /*---------- |
| * PlannerGlobal |
| * Global information for planning/optimization |
| * |
| * PlannerGlobal holds state for an entire planner invocation; this state |
| * is shared across all levels of sub-Queries that exist in the command being |
| * planned. |
| *---------- |
| */ |
| typedef struct PlannerGlobal |
| { |
| NodeTag type; |
| |
| ParamListInfo boundParams; /* Param values provided to planner() */ |
| |
| List *paramlist; /* to keep track of cross-level Params */ |
| |
| List *subplans; /* Plans for SubPlan nodes */ |
| |
| List *subrtables; /* Rangetables for SubPlan nodes */ |
| |
| Bitmapset *rewindPlanIDs; /* indices of subplans that require REWIND */ |
| |
| List *finalrtable; /* "flat" rangetable for executor */ |
| |
| List *relationOids; /* OIDs of relations the plan depends on */ |
| |
| List *invalItems; /* other dependencies, as PlanInvalItems */ |
| |
| bool transientPlan; /* redo plan when TransactionXmin changes? */ |
| |
| ApplyShareInputContext share; /* workspace for GPDB plan sharing */ |
| |
| struct QueryResource *resource; /* the resource for the plan to be optimized and executed */ |
| |
| List* relsType; /* relation and relation runtime type list. for hash table may convert to random table in runtime*/ |
| } PlannerGlobal; |
| |
| /* |
| * CtePlanInfo |
| * Information for subplans that are associated with a CTE. |
| */ |
| typedef struct CtePlanInfo |
| { |
| /* |
| * List of subplans that are associated with a CTE. |
| * If a CTE is referenced once, this list contains one element. |
| * If a CTE is referenced multiple times, this list contains multiple plans, |
| * each of which has ShareNode on top. |
| */ |
| List *subplans; |
| |
| /* |
| * The rtable corresponding to the subplan. |
| */ |
| List *subrtable; |
| |
| /* |
| * The pathkeys corresponding to the subplan. |
| */ |
| List *pathkeys; |
| |
| /* |
| * The next plan id in subplans that should be used (starting with 0). |
| */ |
| int nextPlanId; |
| |
| /* |
| * Number of non-shared plans generated for this cte. |
| */ |
| int numNonSharedPlans; |
| } CtePlanInfo; |
| |
| /*---------- |
| * PlannerInfo |
| * Per-query information for planning/optimization |
| * |
| * This struct is conventionally called "root" in all the planner routines. |
| * It holds links to all of the planner's working state, in addition to the |
| * original Query. Note that at present the planner extensively modifies |
| * the passed-in Query data structure; someday that should stop. |
| *---------- |
| */ |
| typedef struct PlannerInfo |
| { |
| NodeTag type; |
| |
| Query *parse; /* the Query being planned */ |
| |
| PlannerGlobal *glob; /* global info for current planner run */ |
| |
| Index query_level; /* 1 at the outermost Query */ |
| |
| struct PlannerInfo *parent_root; /* NULL at outermost Query */ |
| |
| /* |
| * simple_rel_array holds pointers to "base rels" and "other rels" (see |
| * comments for RelOptInfo for more info). It is indexed by rangetable |
| * index (so entry 0 is always wasted). Entries can be NULL when an RTE |
| * does not correspond to a base relation, such as a join RTE or an |
| * unreferenced view RTE; or if the RelOptInfo hasn't been made yet. |
| */ |
| struct RelOptInfo **simple_rel_array; /* All 1-relation RelOptInfos */ |
| int simple_rel_array_size; /* allocated size of array */ |
| |
| /* |
| * simple_rte_array is the same length as simple_rel_array and holds |
| * pointers to the associated rangetable entries. This lets us avoid |
| * rt_fetch(), which can be a bit slow once large inheritance sets have |
| * been expanded. |
| */ |
| RangeTblEntry **simple_rte_array; /* rangetable as an array */ |
| |
| /* |
| * join_rel_list is a list of all join-relation RelOptInfos we have |
| * considered in this planning run. For small problems we just scan the |
| * list to do lookups, but when there are many join relations we build a |
| * hash table for faster lookups. The hash table is present and valid |
| * when join_rel_hash is not NULL. Note that we still maintain the list |
| * even when using the hash table for lookups; this simplifies life for |
| * GEQO. |
| */ |
| List *join_rel_list; /* list of join-relation RelOptInfos */ |
| struct HTAB *join_rel_hash; /* optional hashtable for join relations */ |
| |
| /* Note: Prior to 3.4, these fields were in the Query node. Now they |
| * are managed here for later installation in PlannedStmt. |
| */ |
| List *resultRelations; /* integer list of RT indexes, or NIL */ |
| PartitionNode *result_partitions; |
| List *returningLists; /* list of lists of TargetEntry, or NIL */ |
| List *result_aosegnos; |
| |
| List *init_plans; /* init SubPlans for query */ |
| |
| List *list_cteplaninfo; /* list of CtePlannerInfo, one for each CTE */ |
| |
| List *equi_key_list; /* list of lists of equijoined PathKeyItems */ |
| |
| /* Jointree result is a subset of the cross product of these relids... */ |
| Relids currlevel_relids; /* CDB: all relids of current query level, |
| * omitting any pulled-up subquery relids */ |
| |
| /* |
| * Outer join info |
| */ |
| List *left_join_clauses; /* list of RestrictInfos for outer |
| * join clauses w/nonnullable var on |
| * left */ |
| |
| List *right_join_clauses; /* list of RestrictInfos for outer |
| * join clauses w/nonnullable var on |
| * right */ |
| |
| List *full_join_clauses; /* list of RestrictInfos for full |
| * outer join clauses */ |
| |
| List *oj_info_list; /* list of OuterJoinInfos */ |
| |
| List *in_info_list; /* list of InClauseInfos */ |
| |
| List *append_rel_list; /* list of AppendRelInfos */ |
| |
| List *query_pathkeys; /* desired pathkeys for query_planner(), and |
| * actual pathkeys afterwards */ |
| |
| List *group_pathkeys; /* groupClause pathkeys, if any */ |
| List *sort_pathkeys; /* sortClause pathkeys, if any */ |
| |
| MemoryContext planner_cxt; /* context holding PlannerInfo */ |
| |
| double total_table_pages; /* # of pages in all tables of query */ |
| |
| double tuple_fraction; /* tuple_fraction passed to query_planner */ |
| |
| bool hasJoinRTEs; /* true if any RTEs are RTE_JOIN kind */ |
| bool hasOuterJoins; /* true if any RTEs are outer joins */ |
| bool hasHavingQual; /* true if havingQual was non-null */ |
| bool hasPseudoConstantQuals; /* true if any RestrictInfo has |
| * pseudoconstant = true */ |
| |
| /* At the end to avoid breaking existing 8.2 add-ons */ |
| List *initial_rels; /* RelOptInfos we are now trying to join */ |
| |
| PlannerConfig *config; /* Planner configuration */ |
| |
| } PlannerInfo; |
| |
| |
| /* |
| * In places where it's known that simple_rte_array[] must have been prepared |
| * already, we just index into it to fetch RTEs. In code that might be |
| * executed before or after entering query_planner(), use this macro. |
| */ |
| #define planner_rt_fetch(rti, root) \ |
| ((root)->simple_rte_array ? (root)->simple_rte_array[rti] : \ |
| rt_fetch(rti, (root)->parse->rtable)) |
| |
| |
| /* |
| * Fetch the Plan associated with a SubPlan node during planning. |
| */ |
| static inline struct Plan *planner_subplan_get_plan(struct PlannerInfo *root, SubPlan *subplan) |
| { |
| return (Plan *) list_nth(root->glob->subplans, subplan->plan_id - 1); |
| } |
| |
| /** |
| * Fetch the rtable list for a subplan |
| */ |
| static inline struct List *planner_subplan_get_rtable(struct PlannerInfo *root, SubPlan *subplan) |
| { |
| return (List *) list_nth(root->glob->subrtables, subplan->plan_id - 1); |
| } |
| |
| /* |
| * Rewrite the Plan associated with a SubPlan node during planning. |
| */ |
| static inline void planner_subplan_put_plan(struct PlannerInfo *root, SubPlan *subplan, Plan *plan) |
| { |
| ListCell *cell = list_nth_cell(root->glob->subplans, subplan->plan_id-1); |
| cell->data.ptr_value = plan; |
| } |
| |
| |
| /*---------- |
| * RelOptInfo |
| * Per-relation information for planning/optimization |
| * |
| * For planning purposes, a "base rel" is either a plain relation (a table) |
| * or the output of a sub-SELECT or function that appears in the range table. |
| * In either case it is uniquely identified by an RT index. A "joinrel" |
| * is the joining of two or more base rels. A joinrel is identified by |
| * the set of RT indexes for its component baserels. We create RelOptInfo |
| * nodes for each baserel and joinrel, and store them in the PlannerInfo's |
| * simple_rel_array and join_rel_list respectively. |
| * |
| * Note that there is only one joinrel for any given set of component |
| * baserels, no matter what order we assemble them in; so an unordered |
| * set is the right datatype to identify it with. |
| * |
| * We also have "other rels", which are like base rels in that they refer to |
| * single RT indexes; but they are not part of the join tree, and are given |
| * a different RelOptKind to identify them. |
| * |
| * Currently the only kind of otherrels are those made for member relations |
| * of an "append relation", that is an inheritance set or UNION ALL subquery. |
| * An append relation has a parent RTE that is a base rel, which represents |
| * the entire append relation. The member RTEs are otherrels. The parent |
| * is present in the query join tree but the members are not. The member |
| * RTEs and otherrels are used to plan the scans of the individual tables or |
| * subqueries of the append set; then the parent baserel is given an Append |
| * plan comprising the best plans for the individual member rels. (See |
| * comments for AppendRelInfo for more information.) |
| * |
| * At one time we also made otherrels to represent join RTEs, for use in |
| * handling join alias Vars. Currently this is not needed because all join |
| * alias Vars are expanded to non-aliased form during preprocess_expression. |
| * |
| * Parts of this data structure are specific to various scan and join |
| * mechanisms. It didn't seem worth creating new node types for them. |
| * |
| * relids - Set of base-relation identifiers; it is a base relation |
| * if there is just one, a join relation if more than one |
| * rows - estimated number of tuples in the relation after restriction |
| * clauses have been applied (ie, output rows of a plan for it) |
| * width - avg. number of bytes per tuple in the relation after the |
| * appropriate projections have been done (ie, output width) |
| * reltargetlist - List of Var nodes for the attributes we need to |
| * output from this relation (in no particular order) |
| * NOTE: in a child relation, may contain RowExprs |
| * pathlist - List of Path nodes, one for each potentially useful |
| * method of generating the relation |
| * cheapest_startup_path - the pathlist member with lowest startup cost |
| * (regardless of its ordering) |
| * cheapest_total_path - the pathlist member with lowest total cost |
| * (regardless of its ordering) |
| * cheapest_unique_path - for caching cheapest path to produce unique |
| * (no duplicates) output from relation |
| * |
| * If the relation is a base relation it will have these fields set: |
| * |
| * relid - RTE index (this is redundant with the relids field, but |
| * is provided for convenience of access) |
| * rtekind - distinguishes plain relation, subquery, or function RTE |
| * min_attr, max_attr - range of valid AttrNumbers for rel |
| * attr_needed - array of bitmapsets indicating the highest joinrel |
| * in which each attribute is needed; if bit 0 is set then |
| * the attribute is needed as part of final targetlist |
| * attr_widths - cache space for per-attribute width estimates; |
| * zero means not computed yet |
| * 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) |
| * tuples - number of tuples in relation (not considering restrictions) |
| * subplan - plan for subquery (NULL if it's not a subquery) |
| * subrtable - rangetable for subquery (NIL if it's not a subquery) |
| * |
| * Note: for a subquery, tuples and subplan are not set immediately |
| * upon creation of the RelOptInfo object; they are filled in when |
| * set_base_rel_pathlist processes the object. |
| * |
| * For otherrels that are appendrel members, these fields are filled |
| * in just as for a baserel. |
| * |
| * The presence of the remaining fields depends on the restrictions |
| * and joins that the relation participates in: |
| * |
| * baserestrictinfo - List of RestrictInfo nodes, containing info about |
| * each non-join qualification clause in which this relation |
| * participates (only used for base rels) |
| * baserestrictcost - Estimated cost of evaluating the baserestrictinfo |
| * clauses at a single tuple (only used for base rels) |
| * joininfo - List of RestrictInfo nodes, containing info about each |
| * join clause in which this relation participates |
| * index_outer_relids - only used for base rels; set of outer relids |
| * that participate in indexable joinclauses for this rel |
| * index_inner_paths - only used for base rels; list of InnerIndexscanInfo |
| * nodes showing best indexpaths for various subsets of |
| * index_outer_relids. |
| * |
| * Note: Keeping a restrictinfo list in the RelOptInfo is useful only for |
| * base rels, because for a join rel the set of clauses that are treated as |
| * restrict clauses varies depending on which sub-relations we choose to join. |
| * (For example, in a 3-base-rel join, a clause relating rels 1 and 2 must be |
| * treated as a restrictclause if we join {1} and {2 3} to make {1 2 3}; but |
| * if we join {1 2} and {3} then that clause will be a restrictclause in {1 2} |
| * and should not be processed again at the level of {1 2 3}.) Therefore, |
| * the restrictinfo list in the join case appears in individual JoinPaths |
| * (field joinrestrictinfo), not in the parent relation. But it's OK for |
| * the RelOptInfo to store the joininfo list, because that is the same |
| * for a given rel no matter how we form it. |
| * |
| * We store baserestrictcost in the RelOptInfo (for base relations) because |
| * we know we will need it at least once (to price the sequential scan) |
| * and may need it multiple times to price index scans. |
| *---------- |
| */ |
| typedef enum RelOptKind |
| { |
| RELOPT_BASEREL, |
| RELOPT_JOINREL, |
| RELOPT_OTHER_MEMBER_REL |
| } RelOptKind; |
| |
| typedef struct RelOptInfo |
| { |
| NodeTag type; |
| |
| RelOptKind reloptkind; |
| |
| /* all relations included in this RelOptInfo */ |
| Relids relids; /* set of base relids (rangetable indexes) */ |
| |
| /* size estimates generated by planner */ |
| double rows; /* estimated number of result tuples */ |
| int width; /* estimated avg width of result tuples */ |
| bool onerow; /* true => rel is inherently 1 row or empty */ |
| |
| /* materialization information */ |
| List *reltargetlist; /* needed Vars */ |
| List *pathlist; /* Path structures */ |
| struct Path *cheapest_startup_path; |
| struct Path *cheapest_total_path; |
| struct Path *cheapest_unique_path; |
| struct CdbRelDedupInfo *dedup_info; /* subquery dup removal info, or NULL */ |
| |
| /* information about a base rel (not set for join rels!) */ |
| Index relid; |
| RTEKind rtekind; /* RELATION, SUBQUERY, or FUNCTION */ |
| AttrNumber min_attr; /* smallest attrno of rel (often <0) */ |
| 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 *indexlist; |
| BlockNumber pages; |
| double tuples; |
| struct GpPolicy *cdbpolicy; /* distribution of stored tuples */ |
| bool cdb_default_stats_used; /* true if ANALYZE needed */ |
| struct Plan *subplan; /* if subquery */ |
| List *subrtable; /* if subquery */ |
| |
| /* used by external scan */ |
| List *locationlist; |
| char *execcommand; |
| char fmttype; |
| char *fmtopts; |
| int32 rejectlimit; |
| char rejectlimittype; |
| Oid fmterrtbl; |
| int32 ext_encoding; |
| bool isrescannable; /* true for ext tables false for ext web tables */ |
| bool writable; /* true for writable, false for readable ext tables*/ |
| |
| /* used by various scans and joins: */ |
| List *baserestrictinfo; /* RestrictInfo structures (if base |
| * rel) */ |
| QualCost baserestrictcost; /* cost of evaluating the above */ |
| List *joininfo; /* RestrictInfo structures for join clauses |
| * involving this rel */ |
| |
| /* cached info about inner indexscan paths for relation: */ |
| Relids index_outer_relids; /* other relids in indexable join |
| * clauses */ |
| List *index_inner_paths; /* InnerIndexscanInfo nodes */ |
| |
| /* |
| * Inner indexscans are not in the main pathlist because they are not |
| * usable except in specific join contexts. We use the index_inner_paths |
| * list just to avoid recomputing the best inner indexscan repeatedly for |
| * similar outer relations. See comments for InnerIndexscanInfo. |
| */ |
| } RelOptInfo; |
| |
| /* |
| * IndexOptInfo |
| * Per-index information for planning/optimization |
| * |
| * Prior to Postgres 7.0, RelOptInfo was used to describe both relations |
| * and indexes, but that created confusion without actually doing anything |
| * useful. So now we have a separate IndexOptInfo struct for indexes. |
| * |
| * classlist[], indexkeys[], and ordering[] have ncolumns entries. |
| * Zeroes in the indexkeys[] array indicate index columns that are |
| * expressions; there is one element in indexprs for each such column. |
| * |
| * Note: for historical reasons, the classlist and ordering arrays have |
| * an extra entry that is always zero. Some code scans until it sees a |
| * zero entry, rather than looking at ncolumns. |
| * |
| * The indexprs and indpred expressions have been run through |
| * prepqual.c and eval_const_expressions() for ease of matching to |
| * WHERE clauses. indpred is in implicit-AND form. |
| */ |
| |
| typedef struct IndexOptInfo |
| { |
| NodeTag type; |
| |
| Oid indexoid; /* OID of the index relation */ |
| RelOptInfo *rel; /* back-link to index's table */ |
| |
| /* statistics from pg_class */ |
| BlockNumber pages; /* number of disk pages in index */ |
| double tuples; /* number of index tuples in index */ |
| |
| /* index descriptor information */ |
| int ncolumns; /* number of columns in index */ |
| Oid *classlist; /* OIDs of operator classes for columns */ |
| int *indexkeys; /* column numbers of index's keys, or 0 */ |
| Oid *ordering; /* OIDs of sort operators for each column */ |
| Oid relam; /* OID of the access method (in pg_am) */ |
| |
| RegProcedure amcostestimate; /* OID of the access method's cost fcn */ |
| |
| List *indexprs; /* expressions for non-simple index columns */ |
| List *indpred; /* predicate if a partial index, else NIL */ |
| |
| bool predOK; /* true if predicate matches query */ |
| bool unique; /* true if a unique index */ |
| bool amoptionalkey; /* can query omit key for the first column? */ |
| bool cdb_default_stats_used; /* true if ANALYZE needed */ |
| int num_leading_eq; /* CDB: always 0, except amcostestimate proc may |
| * set it briefly; it is transferred forthwith |
| * to the IndexPath (q.v.), then reset. Kludge. |
| */ |
| } IndexOptInfo; |
| |
| |
| /* |
| * CdbRelColumnInfo |
| * |
| * Describes a synthetic column to be added to a baserel's targetlist. |
| * The pseudocols field of the RTE points to a List of CdbRelColumnInfo. |
| */ |
| typedef struct CdbRelColumnInfo |
| { |
| NodeTag type; /* T_CdbRelColumnInfo */ |
| |
| AttrNumber pseudoattno; /* FirstLowInvalidHeapAttributeNumber |
| * minus the 0-based position of the |
| * CdbRelColumnInfo node in the |
| * rte->pseudocols list |
| */ |
| AttrNumber targetresno; /* 1-based position of the pseudo |
| * column in the rel's targetlist |
| */ |
| Expr *defexpr; /* expr to be evaluated in targetlist */ |
| Relids where_needed; /* set of relids whose quals use col */ |
| int32 attr_width; /* expected #bytes for column value */ |
| char colname[NAMEDATALEN+1]; /* name for EXPLAIN */ |
| } CdbRelColumnInfo; |
| |
| |
| /* |
| * CdbRelDedupInfo |
| * |
| * One of these hangs off each RelOptInfo entry whose paths might need |
| * special treatment for duplicate suppression for flattened subqueries. |
| */ |
| typedef struct CdbRelDedupInfo |
| { |
| NodeTag type; /* T_CdbRelDedupInfo */ |
| |
| Relids prejoin_dedup_subqrelids; |
| /* relids of subqueries' own (righthand) |
| * tables for those subqueries that have |
| * all of their own tables present in |
| * this rel. |
| */ |
| Relids spent_subqrelids; /* set of subquery relids that are |
| * inputs to this rel but won't be |
| * referenced again downstream (i.e., |
| * are not mentioned in reltargetlist). |
| * Can use JOIN_IN when inner relids |
| * are a subset of spent_subq_relids. |
| */ |
| bool try_postjoin_dedup; /* true => this rel includes all inputs |
| * required (including lefthand and |
| * correlating inputs as well as the |
| * subqueries' own tables) to fully |
| * evaluate the subqueries indicated by |
| * prejoin_dedup_subqrelids. |
| */ |
| bool no_more_subqueries; /* true => this rel includes all inputs |
| * required for all flattened subqueries |
| * of the current query level. |
| */ |
| struct InClauseInfo *join_unique_ininfo; |
| /* uncorrelated "= ANY" subquery with |
| * exactly the same relids as this rel. |
| */ |
| List *later_dedup_pathlist; /* List of Path. Contains paths which |
| * yield this rel but lack duplicate |
| * suppression which is to occur later. |
| * Their subq_complete flags are false. |
| */ |
| struct Path *cheapest_startup_path; /* cheapest of later_dedup_pathlist */ |
| struct Path *cheapest_total_path; /* cheapest of later_dedup_pathlist */ |
| } CdbRelDedupInfo; |
| |
| |
| /* |
| * PathKeys |
| * |
| * The sort ordering of a path is represented by a list of sublists of |
| * PathKeyItem nodes. An empty list implies no known ordering. Otherwise |
| * the first sublist represents the primary sort key, the second the |
| * first secondary sort key, etc. Each sublist contains one or more |
| * PathKeyItem nodes, each of which can be taken as the attribute that |
| * appears at that sort position. (See optimizer/README for more |
| * information.) |
| */ |
| |
| typedef struct PathKeyItem |
| { |
| NodeTag type; |
| |
| Node *key; /* the item that is ordered */ |
| Oid sortop; /* the ordering operator ('<' op) */ |
| Relids cdb_key_relids; /* set of relids referenced by key expr */ |
| int cdb_num_relids; /* num of relids referenced by key expr */ |
| |
| /* |
| * key typically points to a Var node, ie a relation attribute, but it can |
| * also point to an arbitrary expression representing the value indexed by |
| * an index expression. |
| */ |
| } PathKeyItem; |
| |
| /* |
| * CdbPathKeyItemIsConstant |
| * is true if there is no Var of the current level in the expr |
| * referenced by a given PathKeyItem. |
| */ |
| #define CdbPathKeyItemIsConstant(_pathkeyitem) \ |
| ((_pathkeyitem)->cdb_num_relids == 0) |
| |
| /* |
| * CdbPathkeyEqualsConstant |
| * is true if there is a constant expr in a given set of |
| * equijoin-equivalent exprs represented by a pathkey |
| * (i.e. a List of PathKeyItem). If there is a constant |
| * expr, it will be at the head of the list. |
| */ |
| #define CdbPathkeyEqualsConstant(_pathkey) \ |
| ( (_pathkey) != NIL && \ |
| CdbPathKeyItemIsConstant((PathKeyItem *)linitial(_pathkey)) ) |
| |
| |
| /* |
| * Type "Path" is used as-is for sequential-scan paths. For other |
| * path types it is the first component of a larger struct. |
| * |
| * Note: "pathtype" is the NodeTag of the Plan node we could build from this |
| * Path. It is partially redundant with the Path's NodeTag, but allows us |
| * to use the same Path type for multiple Plan types where there is no need |
| * to distinguish the Plan type during path processing. |
| */ |
| |
| typedef struct Path |
| { |
| NodeTag type; |
| |
| NodeTag pathtype; /* tag identifying scan/join method */ |
| |
| RelOptInfo *parent; /* the relation this path can build */ |
| |
| /* estimated execution costs for path (see costsize.c for more info) */ |
| Cost startup_cost; /* cost expended before fetching any tuples */ |
| Cost total_cost; /* total cost (assuming all tuples fetched) */ |
| |
| EstimatedBytes memory; /* executor RAM needed for Path + kids */ |
| |
| CdbPathLocus locus; /* distribution of the result tuples */ |
| |
| bool motionHazard; /* true => path contains a CdbMotion operator |
| * without a slackening operator above it */ |
| |
| bool rescannable; /* CDB: true => path can accept ExecRescan call |
| */ |
| bool subq_complete; /* CDB: true => there is no flattened subquery |
| * having all of its tables present in this rel |
| * but still needing duplicate suppression. |
| * Set by add_path(). |
| */ |
| List *pathkeys; /* sort ordering of path's output */ |
| /* pathkeys is a List of Lists of PathKeyItem nodes; see above */ |
| } Path; |
| |
| /* |
| * AppendOnlyPath is used for append-only table scans. |
| */ |
| typedef struct AppendOnlyPath |
| { |
| Path path; |
| |
| /* for now it's pretty plain.. */ |
| } AppendOnlyPath; |
| |
| /* |
| * ParquetPath is used for parquet table scans. |
| */ |
| typedef struct ParquetPath |
| { |
| Path path; |
| |
| /* for now it's pretty plain.. */ |
| } ParquetPath; |
| |
| /* |
| * ExternalPath is used for external table scans. |
| */ |
| typedef struct ExternalPath |
| { |
| Path path; |
| |
| /* for now it's pretty plain.. */ |
| } ExternalPath; |
| |
| |
| /*---------- |
| * IndexPath represents an index scan over a single index. |
| * |
| * 'indexinfo' is the index to be scanned. |
| * |
| * 'indexclauses' is a list of index qualification clauses, with implicit |
| * AND semantics across the list. Each clause is a RestrictInfo node from |
| * the query's WHERE or JOIN conditions. |
| * |
| * 'indexquals' has the same structure as 'indexclauses', but it contains |
| * the actual indexqual conditions that can be used with the index. |
| * In simple cases this is identical to 'indexclauses', but when special |
| * indexable operators appear in 'indexclauses', they are replaced by the |
| * derived indexscannable conditions in 'indexquals'. |
| * |
| * 'isjoininner' is TRUE if the path is a nestloop inner scan (that is, |
| * some of the index conditions are join rather than restriction clauses). |
| * Note that the path costs will be calculated differently from a plain |
| * indexscan in this case, and in addition there's a special 'rows' value |
| * different from the parent RelOptInfo's (see below). |
| * |
| * 'indexscandir' is one of: |
| * ForwardScanDirection: forward scan of an ordered index |
| * BackwardScanDirection: backward scan of an ordered index |
| * NoMovementScanDirection: scan of an unordered index, or don't care |
| * (The executor doesn't care whether it gets ForwardScanDirection or |
| * NoMovementScanDirection for an indexscan, but the planner wants to |
| * distinguish ordered from unordered indexes for building pathkeys.) |
| * |
| * 'indextotalcost' and 'indexselectivity' are saved in the IndexPath so that |
| * we need not recompute them when considering using the same index in a |
| * bitmap index/heap scan (see BitmapHeapPath). The costs of the IndexPath |
| * itself represent the costs of an IndexScan plan type. |
| * |
| * 'rows' is the estimated result tuple count for the indexscan. This |
| * is the same as path.parent->rows for a simple indexscan, but it is |
| * different for a nestloop inner scan, because the additional indexquals |
| * coming from join clauses make the scan more selective than the parent |
| * rel's restrict clauses alone would do. |
| *---------- |
| */ |
| typedef struct IndexPath |
| { |
| Path path; |
| IndexOptInfo *indexinfo; |
| List *indexclauses; |
| List *indexquals; |
| bool isjoininner; |
| ScanDirection indexscandir; |
| Cost indextotalcost; |
| Selectivity indexselectivity; |
| double rows; /* estimated number of result tuples */ |
| int num_leading_eq; /* CDB: number of leading key columns matched by |
| * equality predicates in indexquals. If equal |
| * to indexinfo->ncolumns, at most one distinct |
| * value of the index key can satisfy the quals. |
| * Further if the index is unique, we can assume |
| * at most one visible row satisfies the quals. |
| */ |
| } IndexPath; |
| |
| /* |
| * BitmapHeapPath represents one or more indexscans that generate TID bitmaps |
| * instead of directly accessing the heap, followed by AND/OR combinations |
| * to produce a single bitmap, followed by a heap scan that uses the bitmap. |
| * Note that the output is always considered unordered, since it will come |
| * out in physical heap order no matter what the underlying indexes did. |
| * |
| * The individual indexscans are represented by IndexPath nodes, and any |
| * logic on top of them is represented by a tree of BitmapAndPath and |
| * BitmapOrPath nodes. Notice that we can use the same IndexPath node both |
| * to represent a regular IndexScan plan, and as the child of a BitmapHeapPath |
| * that represents scanning the same index using a BitmapIndexScan. The |
| * startup_cost and total_cost figures of an IndexPath always represent the |
| * costs to use it as a regular IndexScan. The costs of a BitmapIndexScan |
| * can be computed using the IndexPath's indextotalcost and indexselectivity. |
| * |
| * BitmapHeapPaths can be nestloop inner indexscans. The isjoininner and |
| * rows fields serve the same purpose as for plain IndexPaths. |
| */ |
| typedef struct BitmapHeapPath |
| { |
| Path path; |
| Path *bitmapqual; /* IndexPath, BitmapAndPath, BitmapOrPath */ |
| bool isjoininner; /* T if it's a nestloop inner scan */ |
| double rows; /* estimated number of result tuples */ |
| } BitmapHeapPath; |
| |
| /* |
| * NOTE: This is a copy of the BitmapHeapPath structure. |
| */ |
| typedef struct BitmapAppendOnlyPath |
| { |
| Path path; |
| Path *bitmapqual; /* IndexPath, BitmapAndPath, BitmapOrPath */ |
| bool isjoininner; /* T if it's a nestloop inner scan */ |
| double rows; /* estimated number of result tuples */ |
| bool isAORow; /* If this is for AO Row tables */ |
| } BitmapAppendOnlyPath; |
| |
| typedef struct BitmapTableScanPath |
| { |
| Path path; |
| Path *bitmapqual; /* IndexPath, BitmapAndPath, BitmapOrPath */ |
| bool isjoininner; /* T if it's a nestloop inner scan */ |
| double rows; /* estimated number of result tuples */ |
| } BitmapTableScanPath; |
| |
| /* |
| * BitmapAndPath represents a BitmapAnd plan node; it can only appear as |
| * part of the substructure of a BitmapHeapPath. The Path structure is |
| * a bit more heavyweight than we really need for this, but for simplicity |
| * we make it a derivative of Path anyway. |
| */ |
| typedef struct BitmapAndPath |
| { |
| Path path; |
| List *bitmapquals; /* IndexPaths and BitmapOrPaths */ |
| Selectivity bitmapselectivity; |
| } BitmapAndPath; |
| |
| /* |
| * BitmapOrPath represents a BitmapOr plan node; it can only appear as |
| * part of the substructure of a BitmapHeapPath. The Path structure is |
| * a bit more heavyweight than we really need for this, but for simplicity |
| * we make it a derivative of Path anyway. |
| */ |
| typedef struct BitmapOrPath |
| { |
| Path path; |
| List *bitmapquals; /* IndexPaths and BitmapAndPaths */ |
| Selectivity bitmapselectivity; |
| } BitmapOrPath; |
| |
| /* |
| * TidPath represents a scan by TID |
| * |
| * tidquals is an implicitly OR'ed list of qual expressions of the form |
| * "CTID = pseudoconstant" or "CTID = ANY(pseudoconstant_array)". |
| * Note they are bare expressions, not RestrictInfos. |
| */ |
| typedef struct TidPath |
| { |
| Path path; |
| List *tidquals; /* qual(s) involving CTID = something */ |
| } TidPath; |
| |
| /* |
| * CdbMotionPath represents transmission of the child Path results |
| * from a set of sending processes to a set of receiving processes. |
| */ |
| typedef struct CdbMotionPath |
| { |
| Path path; |
| Path *subpath; |
| } CdbMotionPath; |
| |
| /* |
| * AppendPath represents an Append plan, ie, successive execution of |
| * several member plans. |
| * |
| * Note: it is possible for "subpaths" to contain only one, or even no, |
| * elements. These cases are optimized during create_append_plan. |
| */ |
| typedef struct AppendPath |
| { |
| Path path; |
| List *subpaths; /* list of component Paths */ |
| } AppendPath; |
| |
| /* |
| * ResultPath represents use of a Result plan node to compute a variable-free |
| * targetlist with no underlying tables (a "SELECT expressions" query). |
| * The query could have a WHERE clause, too, represented by "quals". |
| * |
| * Note that quals is a list of bare clauses, not RestrictInfos. |
| */ |
| typedef struct ResultPath |
| { |
| Path path; |
| Path *subpath; |
| List *quals; |
| } ResultPath; |
| |
| /* |
| * MaterialPath represents use of a Material plan node, i.e., caching of |
| * the output of its subpath. This is used when the subpath is expensive |
| * and needs to be scanned repeatedly, or when we need mark/restore ability |
| * and the subpath doesn't have it. |
| */ |
| typedef struct MaterialPath |
| { |
| Path path; |
| Path *subpath; |
| bool cdb_strict; /* true => consume and store all input tuples |
| * before yielding output tuples |
| * false => memoize tuples as they stream thru |
| */ |
| } MaterialPath; |
| |
| /* |
| * UniquePath represents elimination of distinct rows from the output of |
| * its subpath. |
| * |
| * This is unlike the other Path nodes in that it can actually generate |
| * different plans: either hash-based or sort-based implementation, or a |
| * no-op if the input path can be proven distinct already. The decision |
| * is sufficiently localized that it's not worth having separate Path node |
| * types. (Note: in the no-op case, we could eliminate the UniquePath node |
| * entirely and just return the subpath; but it's convenient to have a |
| * UniquePath in the path tree to signal upper-level routines that the input |
| * is known distinct.) |
| */ |
| typedef enum |
| { |
| UNIQUE_PATH_NOOP, /* input is known unique already */ |
| UNIQUE_PATH_HASH, /* use hashing */ |
| UNIQUE_PATH_SORT, /* use sorting */ |
| UNIQUE_PATH_LIMIT1 /* CDB: take at most one row from the subpath */ |
| } UniquePathMethod; |
| |
| typedef struct UniquePath |
| { |
| Path path; |
| Path *subpath; |
| UniquePathMethod umethod; |
| double rows; /* estimated number of result tuples */ |
| List *distinct_on_exprs; |
| /* CDB: list of exprs to be uniqueified */ |
| Relids distinct_on_rowid_relids; |
| /* CDB: set of relids whose row ids are to be |
| * uniqueified. |
| */ |
| bool must_repartition; |
| /* CDB: true => add Motion atop subpath */ |
| } UniquePath; |
| |
| /* |
| * All join-type paths share these fields. |
| */ |
| |
| typedef struct JoinPath |
| { |
| Path path; |
| |
| JoinType jointype; |
| |
| Path *outerjoinpath; /* path for the outer side of the join */ |
| Path *innerjoinpath; /* path for the inner side of the join */ |
| |
| List *joinrestrictinfo; /* RestrictInfos to apply to join */ |
| |
| /* |
| * See the notes for RelOptInfo to understand why joinrestrictinfo is |
| * needed in JoinPath, and can't be merged into the parent RelOptInfo. |
| */ |
| } JoinPath; |
| |
| /* |
| * IsJoinPath |
| * Returns true if the node type is one that derives from JoinPath. |
| */ |
| #define IsJoinPath(node) \ |
| (IsA((node), NestPath) || \ |
| IsA((node), HashPath) || \ |
| IsA((node), MergePath)) |
| |
| /* |
| * A nested-loop path has special fields which may be used if it falls back to |
| * plan-B during execution. |
| */ |
| |
| typedef struct NestPath |
| { |
| JoinPath jpath; |
| } NestPath; |
| |
| /* |
| * A mergejoin path has these fields. |
| * |
| * path_mergeclauses lists the clauses (in the form of RestrictInfos) |
| * that will be used in the merge. |
| * |
| * Note that the mergeclauses are a subset of the parent relation's |
| * restriction-clause list. Any join clauses that are not mergejoinable |
| * appear only in the parent's restrict list, and must be checked by a |
| * qpqual at execution time. |
| * |
| * outersortkeys (resp. innersortkeys) is NIL if the outer path |
| * (resp. inner path) is already ordered appropriately for the |
| * mergejoin. If it is not NIL then it is a PathKeys list describing |
| * the ordering that must be created by an explicit sort step. |
| */ |
| |
| typedef struct MergePath |
| { |
| JoinPath jpath; |
| List *path_mergeclauses; /* join clauses to be used for merge */ |
| List *outersortkeys; /* keys for explicit sort, if any */ |
| List *innersortkeys; /* keys for explicit sort, if any */ |
| } MergePath; |
| |
| /* |
| * A hashjoin path has these fields. |
| * |
| * The remarks above for mergeclauses apply for hashclauses as well. |
| * |
| * Hashjoin does not care what order its inputs appear in, so we have |
| * no need for sortkeys. |
| */ |
| |
| typedef struct HashPath |
| { |
| JoinPath jpath; |
| List *path_hashclauses; /* join clauses used for hashing */ |
| } HashPath; |
| |
| /* |
| * Restriction clause info. |
| * |
| * We create one of these for each AND sub-clause of a restriction condition |
| * (WHERE or JOIN/ON clause). Since the restriction clauses are logically |
| * ANDed, we can use any one of them or any subset of them to filter out |
| * tuples, without having to evaluate the rest. The RestrictInfo node itself |
| * stores data used by the optimizer while choosing the best query plan. |
| * |
| * If a restriction clause references a single base relation, it will appear |
| * in the baserestrictinfo list of the RelOptInfo for that base rel. |
| * |
| * If a restriction clause references more than one base rel, it will |
| * appear in the joininfo list of every RelOptInfo that describes a strict |
| * subset of the base rels mentioned in the clause. The joininfo lists are |
| * used to drive join tree building by selecting plausible join candidates. |
| * The clause cannot actually be applied until we have built a join rel |
| * containing all the base rels it references, however. |
| * |
| * When we construct a join rel that includes all the base rels referenced |
| * in a multi-relation restriction clause, we place that clause into the |
| * joinrestrictinfo lists of paths for the join rel, if neither left nor |
| * right sub-path includes all base rels referenced in the clause. The clause |
| * will be applied at that join level, and will not propagate any further up |
| * the join tree. (Note: the "predicate migration" code was once intended to |
| * push restriction clauses up and down the plan tree based on evaluation |
| * costs, but it's dead code and is unlikely to be resurrected in the |
| * foreseeable future.) |
| * |
| * Note that in the presence of more than two rels, a multi-rel restriction |
| * might reach different heights in the join tree depending on the join |
| * sequence we use. So, these clauses cannot be associated directly with |
| * the join RelOptInfo, but must be kept track of on a per-join-path basis. |
| * |
| * When dealing with outer joins we have to be very careful about pushing qual |
| * clauses up and down the tree. An outer join's own JOIN/ON conditions must |
| * be evaluated exactly at that join node, and any quals appearing in WHERE or |
| * in a JOIN above the outer join cannot be pushed down below the outer join. |
| * Otherwise the outer join will produce wrong results because it will see the |
| * wrong sets of input rows. All quals are stored as RestrictInfo nodes |
| * during planning, but there's a flag to indicate whether a qual has been |
| * pushed down to a lower level than its original syntactic placement in the |
| * join tree would suggest. If an outer join prevents us from pushing a qual |
| * down to its "natural" semantic level (the level associated with just the |
| * base rels used in the qual) then we mark the qual with a "required_relids" |
| * value including more than just the base rels it actually uses. By |
| * pretending that the qual references all the rels appearing in the outer |
| * join, we prevent it from being evaluated below the outer join's joinrel. |
| * When we do form the outer join's joinrel, we still need to distinguish |
| * those quals that are actually in that join's JOIN/ON condition from those |
| * that appeared elsewhere in the tree and were pushed down to the join rel |
| * because they used no other rels. That's what the is_pushed_down flag is |
| * for; it tells us that a qual is not an OUTER JOIN qual for the set of base |
| * rels listed in required_relids. A clause that originally came from WHERE |
| * or an INNER JOIN condition will *always* have its is_pushed_down flag set. |
| * It's possible for an OUTER JOIN clause to be marked is_pushed_down too, |
| * if we decide that it can be pushed down into the nullable side of the join. |
| * In that case it acts as a plain filter qual for wherever it gets evaluated. |
| * |
| * When application of a qual must be delayed by outer join, we also mark it |
| * with outerjoin_delayed = true. This isn't redundant with required_relids |
| * because that might equal clause_relids whether or not it's an outer-join |
| * clause. |
| * |
| * In general, the referenced clause might be arbitrarily complex. The |
| * kinds of clauses we can handle as indexscan quals, mergejoin clauses, |
| * or hashjoin clauses are fairly limited --- the code for each kind of |
| * path is responsible for identifying the restrict clauses it can use |
| * and ignoring the rest. Clauses not implemented by an indexscan, |
| * mergejoin, or hashjoin will be placed in the plan qual or joinqual field |
| * of the finished Plan node, where they will be enforced by general-purpose |
| * qual-expression-evaluation code. (But we are still entitled to count |
| * their selectivity when estimating the result tuple count, if we |
| * can guess what it is...) |
| * |
| * When the referenced clause is an OR clause, we generate a modified copy |
| * in which additional RestrictInfo nodes are inserted below the top-level |
| * OR/AND structure. This is a convenience for OR indexscan processing: |
| * indexquals taken from either the top level or an OR subclause will have |
| * associated RestrictInfo nodes. |
| * |
| * The can_join flag is set true if the clause looks potentially useful as |
| * a merge or hash join clause, that is if it is a binary opclause with |
| * nonoverlapping sets of relids referenced in the left and right sides. |
| * (Whether the operator is actually merge or hash joinable isn't checked, |
| * however.) |
| * |
| * The pseudoconstant flag is set true if the clause contains no Vars of |
| * the current query level and no volatile functions. Such a clause can be |
| * pulled out and used as a one-time qual in a gating Result node. We keep |
| * pseudoconstant clauses in the same lists as other RestrictInfos so that |
| * the regular clause-pushing machinery can assign them to the correct join |
| * level, but they need to be treated specially for cost and selectivity |
| * estimates. Note that a pseudoconstant clause can never be an indexqual |
| * or merge or hash join clause, so it's of no interest to large parts of |
| * the planner. |
| */ |
| |
| typedef struct RestrictInfo |
| { |
| NodeTag type; |
| |
| Expr *clause; /* the represented clause of WHERE or JOIN */ |
| |
| bool is_pushed_down; /* TRUE if clause was pushed down in level */ |
| |
| bool outerjoin_delayed; /* TRUE if delayed by outer join */ |
| |
| bool can_join; /* see comment above */ |
| |
| bool pseudoconstant; /* see comment above */ |
| |
| /* The set of relids (varnos) actually referenced in the clause: */ |
| Relids clause_relids; |
| |
| /* The set of relids required to evaluate the clause: */ |
| Relids required_relids; |
| |
| /* These fields are set for any binary opclause: */ |
| Relids left_relids; /* relids in left side of clause */ |
| Relids right_relids; /* relids in right side of clause */ |
| |
| /* This field is NULL unless clause is an OR clause: */ |
| Expr *orclause; /* modified clause with RestrictInfos */ |
| |
| /* cache space for cost and selectivity */ |
| QualCost eval_cost; /* eval cost of clause; -1 if not yet set */ |
| Selectivity this_selec; /* selectivity; -1 if not yet set */ |
| |
| /* valid if clause is mergejoinable, else InvalidOid: */ |
| Oid mergejoinoperator; /* copy of clause operator */ |
| Oid left_sortop; /* leftside sortop needed for mergejoin */ |
| Oid right_sortop; /* rightside sortop needed for mergejoin */ |
| |
| /* cache space for mergeclause processing; NIL if not yet set */ |
| List *left_pathkey; /* canonical pathkey for left side */ |
| List *right_pathkey; /* canonical pathkey for right side */ |
| |
| /* cache space for mergeclause processing; -1 if not yet set */ |
| Selectivity left_mergescansel; /* fraction of left side to scan */ |
| Selectivity right_mergescansel; /* fraction of right side to scan */ |
| |
| /* valid if clause is hashjoinable, else InvalidOid: */ |
| Oid hashjoinoperator; /* copy of clause operator */ |
| |
| /* cache space for hashclause processing; -1 if not yet set */ |
| Selectivity left_bucketsize; /* avg bucketsize of left side */ |
| Selectivity right_bucketsize; /* avg bucketsize of right side */ |
| } RestrictInfo; |
| |
| /* |
| * Inner indexscan info. |
| * |
| * An inner indexscan is one that uses one or more joinclauses as index |
| * conditions (perhaps in addition to plain restriction clauses). So it |
| * can only be used as the inner path of a nestloop join where the outer |
| * relation includes all other relids appearing in those joinclauses. |
| * The set of usable joinclauses, and thus the best inner indexscan, |
| * thus varies depending on which outer relation we consider; so we have |
| * to recompute the best such paths for every join. To avoid lots of |
| * redundant computation, we cache the results of such searches. For |
| * each relation we compute the set of possible otherrelids (all relids |
| * appearing in joinquals that could become indexquals for this table). |
| * Two outer relations whose relids have the same intersection with this |
| * set will have the same set of available joinclauses and thus the same |
| * best inner indexscans for the inner relation. By taking the intersection |
| * before scanning the cache, we avoid recomputing when considering |
| * join rels that differ only by the inclusion of irrelevant other rels. |
| * |
| * The search key also includes a bool showing whether the join being |
| * considered is an outer join. Since we constrain the join order for |
| * outer joins, I believe that this bool can only have one possible value |
| * for any particular lookup key; but store it anyway to avoid confusion. |
| */ |
| |
| typedef struct InnerIndexscanInfo |
| { |
| NodeTag type; |
| /* The lookup key: */ |
| Relids other_relids; /* a set of relevant other relids */ |
| bool isouterjoin; /* true if join is outer */ |
| /* Best paths for this lookup key (NULL if no available indexscans): */ |
| Path *cheapest_startup_innerpath; /* cheapest startup cost */ |
| Path *cheapest_total_innerpath; /* cheapest total cost */ |
| } InnerIndexscanInfo; |
| |
| /* |
| * Outer join info. |
| * |
| * One-sided outer joins constrain the order of joining partially but not |
| * completely. We flatten such joins into the planner's top-level list of |
| * relations to join, but record information about each outer join in an |
| * OuterJoinInfo struct. These structs are kept in the PlannerInfo node's |
| * oj_info_list. |
| * |
| * min_lefthand and min_righthand are the sets of base relids that must be |
| * available on each side when performing the outer join. lhs_strict is |
| * true if the outer join's condition cannot succeed when the LHS variables |
| * are all NULL (this means that the outer join can commute with upper-level |
| * outer joins even if it appears in their RHS). We don't bother to set |
| * lhs_strict for FULL JOINs, however. |
| * |
| * It is not valid for either min_lefthand or min_righthand to be empty sets; |
| * if they were, this would break the logic that enforces join order. |
| * |
| * syn_lefthand and syn_righthand are the sets of base relids that are |
| * syntactically below this outer join. (These are needed to help compute |
| * min_lefthand and min_righthand for higher joins, but are not used |
| * thereafter.) |
| * |
| * delay_upper_joins is set TRUE if we detect a pushed-down clause that has |
| * to be evaluated after this join is formed (because it references the RHS). |
| * Any outer joins that have such a clause and this join in their RHS cannot |
| * commute with this join, because that would leave noplace to check the |
| * pushed-down clause. (We don't track this for FULL JOINs, either.) |
| * |
| * Note: OuterJoinInfo directly represents only LEFT JOIN and FULL JOIN; |
| * RIGHT JOIN is handled by switching the inputs to make it a LEFT JOIN. |
| * We make an OuterJoinInfo for FULL JOINs even though there is no flexibility |
| * of planning for them, because this simplifies make_join_rel()'s API. |
| */ |
| |
| typedef struct OuterJoinInfo |
| { |
| NodeTag type; |
| Relids min_lefthand; /* base relids in minimum LHS for join */ |
| Relids min_righthand; /* base relids in minimum RHS for join */ |
| Relids syn_lefthand; /* base relids syntactically within LHS */ |
| Relids syn_righthand; /* base relids syntactically within RHS */ |
| JoinType join_type; /* LEFT, FULL, or ANTI */ |
| bool lhs_strict; /* joinclause is strict for some LHS rel */ |
| bool delay_upper_joins; /* can't commute with upper RHS */ |
| |
| /** |
| * list of lists of equijoined PathKeyItems |
| * only valid for FULL joins. Will contain equi_key sets but ONLY |
| * for tables that are below the LEFT nullable side of the outer join. |
| */ |
| List *left_equi_key_list; |
| |
| /** |
| * list of lists of equijoined PathKeyItems |
| * Will contain equi_key sets but ONLY |
| * for tables that are below the RIGHT nullable side of the outer join. |
| */ |
| List *right_equi_key_list; |
| |
| } OuterJoinInfo; |
| |
| /* |
| * IN clause info. |
| * |
| * When we convert top-level IN quals into join operations, we must restrict |
| * the order of joining and use special join methods at some join points. |
| * We record information about each such IN clause in an InClauseInfo struct. |
| * These structs are kept in the PlannerInfo node's in_info_list. |
| */ |
| |
| typedef struct InClauseInfo |
| { |
| NodeTag type; |
| Relids lefthand; /* base relids in lefthand expressions */ |
| Relids righthand; /* base relids coming from the subselect */ |
| List *sub_targetlist; /* targetlist of original RHS subquery */ |
| |
| /* |
| * Note: sub_targetlist is just a list of Vars or expressions; it does not |
| * contain TargetEntry nodes. |
| */ |
| |
| bool try_join_unique; |
| /* CDB: true => comparison is equality op and |
| * subquery is not correlated. Ok to consider |
| * JOIN_UNIQUE method of duplicate suppression. |
| */ |
| |
| } InClauseInfo; |
| |
| /* |
| * Append-relation info. |
| * |
| * When we expand an inheritable table or a UNION-ALL subselect into an |
| * "append relation" (essentially, a list of child RTEs), we build an |
| * AppendRelInfo for each child RTE. The list of AppendRelInfos indicates |
| * which child RTEs must be included when expanding the parent, and each |
| * node carries information needed to translate Vars referencing the parent |
| * into Vars referencing that child. |
| * |
| * These structs are kept in the PlannerInfo node's append_rel_list. |
| * Note that we just throw all the structs into one list, and scan the |
| * whole list when desiring to expand any one parent. We could have used |
| * a more complex data structure (eg, one list per parent), but this would |
| * be harder to update during operations such as pulling up subqueries, |
| * and not really any easier to scan. Considering that typical queries |
| * will not have many different append parents, it doesn't seem worthwhile |
| * to complicate things. |
| * |
| * Note: after completion of the planner prep phase, any given RTE is an |
| * append parent having entries in append_rel_list if and only if its |
| * "inh" flag is set. We clear "inh" for plain tables that turn out not |
| * to have inheritance children, and (in an abuse of the original meaning |
| * of the flag) we set "inh" for subquery RTEs that turn out to be |
| * flattenable UNION ALL queries. This lets us avoid useless searches |
| * of append_rel_list. |
| * |
| * Note: the data structure assumes that append-rel members are single |
| * baserels. This is OK for inheritance, but it prevents us from pulling |
| * up a UNION ALL member subquery if it contains a join. While that could |
| * be fixed with a more complex data structure, at present there's not much |
| * point because no improvement in the plan could result. |
| */ |
| |
| typedef struct AppendRelInfo |
| { |
| NodeTag type; |
| |
| /* |
| * These fields uniquely identify this append relationship. There can be |
| * (in fact, always should be) multiple AppendRelInfos for the same |
| * parent_relid, but never more than one per child_relid, since a given |
| * RTE cannot be a child of more than one append parent. |
| */ |
| Index parent_relid; /* RT index of append parent rel */ |
| Index child_relid; /* RT index of append child rel */ |
| |
| /* |
| * For an inheritance appendrel, the parent and child are both regular |
| * relations, and we store their rowtype OIDs here for use in translating |
| * whole-row Vars. For a UNION-ALL appendrel, the parent and child are |
| * both subqueries with no named rowtype, and we store InvalidOid here. |
| */ |
| Oid parent_reltype; /* OID of parent's composite type */ |
| Oid child_reltype; /* OID of child's composite type */ |
| |
| /* |
| * The N'th element of this list is the integer column number of the child |
| * column corresponding to the N'th column of the parent. A list element |
| * is zero if it corresponds to a dropped column of the parent (this is |
| * only possible for inheritance cases, not UNION ALL). |
| */ |
| List *col_mappings; /* list of child attribute numbers */ |
| |
| /* |
| * The N'th element of this list is a Var or expression representing the |
| * child column corresponding to the N'th column of the parent. This is |
| * used to translate Vars referencing the parent rel into references to |
| * the child. A list element is NULL if it corresponds to a dropped |
| * column of the parent (this is only possible for inheritance cases, not |
| * UNION ALL). |
| * |
| * This might seem redundant with the col_mappings data, but it is handy |
| * because flattening of sub-SELECTs that are members of a UNION ALL will |
| * cause changes in the expressions that need to be substituted for a |
| * parent Var. Adjusting this data structure lets us track what really |
| * needs to be substituted. |
| * |
| * Notice we only store entries for user columns (attno > 0). Whole-row |
| * Vars are special-cased, and system columns (attno < 0) need no special |
| * translation since their attnos are the same for all tables. |
| * |
| * Caution: the Vars have varlevelsup = 0. Be careful to adjust as needed |
| * when copying into a subquery. |
| */ |
| List *translated_vars; /* Expressions in the child's Vars */ |
| |
| /* |
| * We store the parent table's OID here for inheritance, or InvalidOid for |
| * UNION ALL. This is only needed to help in generating error messages if |
| * an attempt is made to reference a dropped parent column. |
| */ |
| Oid parent_reloid; /* OID of parent relation */ |
| } AppendRelInfo; |
| |
| /* |
| * glob->paramlist keeps track of the PARAM_EXEC slots that we have decided |
| * we need for the query. At runtime these slots are used to pass values |
| * either down into subqueries (for outer references in subqueries) or up out |
| * of subqueries (for the results of a subplan). The n'th entry in the list |
| * (n counts from 0) corresponds to Param->paramid = n. |
| * |
| * Each paramlist item shows the absolute query level it is associated with, |
| * where the outermost query is level 1 and nested subqueries have higher |
| * numbers. The item the parameter slot represents can be one of three kinds: |
| * |
| * A Var: the slot represents a variable of that level that must be passed |
| * down because subqueries have outer references to it. The varlevelsup |
| * value in the Var will always be zero. |
| * |
| * An Aggref (with an expression tree representing its argument): the slot |
| * represents an aggregate expression that is an outer reference for some |
| * subquery. The Aggref itself has agglevelsup = 0, and its argument tree |
| * is adjusted to match in level. |
| * |
| * A Param: the slot holds the result of a subplan (it is a setParam item |
| * for that subplan). The absolute level shown for such items corresponds |
| * to the parent query of the subplan. |
| * |
| * Note: we detect duplicate Var parameters and coalesce them into one slot, |
| * but we do not do this for Aggref or Param slots. |
| */ |
| typedef struct PlannerParamItem |
| { |
| NodeTag type; |
| |
| Node *item; /* the Var, Aggref, or Param */ |
| Index abslevel; /* its absolute query level */ |
| } PlannerParamItem; |
| |
| /* |
| * Partitioning meta data |
| */ |
| |
| /* |
| * convenient representation of a row of pg_partition -- a partitioning level of |
| * a partitioned table or a template for all the partitioning branches at a level. |
| */ |
| typedef struct Partition |
| { |
| NodeTag type; |
| Oid partid; /* OID of row in pg_partition. */ |
| Oid parrelid; /* OID in pg_class of top-level partitioned relation */ |
| char parkind; /* 'r', 'l', or (unsupported) 'h' */ |
| int2 parlevel; /* depth below parent partitioned table */ |
| bool paristemplate; /* just a template, or really a part? */ |
| int2 parnatts; /* number of partitioning attributes */ |
| AttrNumber *paratts;/* attribute number vector */ |
| Oid *parclass; /* operator class vector */ |
| } Partition; |
| |
| struct PartitionNode |
| { |
| NodeTag type; |
| Partition *part; |
| struct PartitionRule *default_part; |
| List *rules; /* rules for this level */ |
| }; |
| |
| /* Individual partitioning rule */ |
| typedef struct PartitionRule |
| { |
| NodeTag type; |
| Oid parruleid; |
| Oid paroid; |
| Oid parchildrelid; |
| Oid parparentoid; |
| bool parisdefault; |
| char *parname; |
| Node *parrangestart; |
| bool parrangestartincl; |
| Node *parrangeend; |
| bool parrangeendincl; |
| Node *parrangeevery; |
| List *parlistvalues; |
| int2 parruleord; |
| List *parreloptions; |
| Oid partemplatespaceId; /* the tablespace id for the |
| * template (or InvalidOid for |
| * non-template rules */ |
| struct PartitionNode *children; /* sub partition */ |
| } PartitionRule; |
| |
| typedef struct PgPartRule |
| { |
| NodeTag type; |
| PartitionNode *pNode; |
| PartitionRule *topRule; /* the rule for the specified partition */ |
| |
| /* a textual representation of the partition id (for error msgs) */ |
| char *partIdStr; |
| bool isName; /* true if partid is name */ |
| int topRuleRank; /* rank of topRule */ |
| char *relname; /* the error msg formatted "relname" */ |
| } PgPartRule; |
| |
| /* |
| * A Mapping created by the QD during data loading that maps a |
| * relation id to the segfile number that is should be inserting |
| * into (in cases of inserting into a partitioned table the QD |
| * assigns a segno for each possible partition child relation). |
| * |
| * It is a node because it needs to get serialized as a part of |
| * CopyStmt. |
| */ |
| typedef struct SegfileMapNode |
| { |
| NodeTag type; |
| Oid relid; |
| List *segnos; |
| } SegfileMapNode; |
| |
| /* |
| * Result relation segment file information |
| * |
| * |
| */ |
| typedef struct ResultRelSegFileInfo |
| { |
| NodeTag type; |
| |
| int32 segno; |
| int64 varblock; |
| int64 tupcount; |
| int32 numfiles; |
| int64 *eof; |
| int64 *uncompressed_eof; |
| } ResultRelSegFileInfo; |
| |
| typedef struct ResultRelSegFileInfoMapNode |
| { |
| NodeTag type; |
| Oid relid; |
| List *segfileinfos; |
| } ResultRelSegFileInfoMapNode; |
| |
| #endif /* RELATION_H */ |