| /* |
| * 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. |
| */ |
| |
| /*------------------------------------------------------------------------- |
| * |
| * allpaths.c |
| * Routines to find possible search paths for processing a query |
| * |
| * Portions Copyright (c) 2005-2008, Greenplum inc |
| * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group |
| * Portions Copyright (c) 1994, Regents of the University of California |
| * |
| * |
| * IDENTIFICATION |
| * $PostgreSQL: pgsql/src/backend/optimizer/path/allpaths.c,v 1.154.2.1 2007/01/28 18:50:48 tgl Exp $ |
| * |
| *------------------------------------------------------------------------- |
| */ |
| |
| #include "postgres.h" |
| |
| #include "catalog/gp_policy.h" /* GpPolicy */ |
| #include "catalog/pg_type.h" /* INT4OID, INT8OID */ |
| #include "nodes/makefuncs.h" |
| #include "nodes/relation.h" |
| #ifdef OPTIMIZER_DEBUG |
| #include "nodes/print.h" |
| #endif |
| #include "optimizer/clauses.h" |
| #include "optimizer/cost.h" |
| #include "optimizer/pathnode.h" |
| #include "optimizer/paths.h" |
| #include "optimizer/plancat.h" |
| #include "optimizer/planmain.h" |
| #include "optimizer/planner.h" |
| #include "optimizer/prep.h" |
| #include "optimizer/var.h" |
| #include "optimizer/planshare.h" |
| #include "parser/parse_clause.h" |
| #include "parser/parse_expr.h" |
| #include "parser/parsetree.h" |
| #include "rewrite/rewriteManip.h" |
| #include "utils/lsyscache.h" |
| |
| #include "cdb/cdbllize.h" /* repartitionPlan */ |
| #include "cdb/cdbmutate.h" /* cdbmutate_warn_ctid_without_segid */ |
| #include "cdb/cdbpath.h" /* cdbpath_rows() */ |
| #include "cdb/cdbsetop.h" /* make_motion... routines */ |
| |
| // TODO: these planner/executor gucs need to be refactored into PlannerConfig. |
| bool gp_enable_sort_limit = FALSE; |
| bool gp_enable_sort_distinct = FALSE; |
| bool gp_enable_mk_sort = true; |
| bool gp_enable_motion_mk_sort = true; |
| |
| static void set_base_rel_pathlists(PlannerInfo *root); |
| static void set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, Index rti); |
| static void set_plain_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, |
| RangeTblEntry *rte); |
| static void set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, |
| Index rti); |
| static bool has_multiple_baserels(PlannerInfo *root); |
| static void set_subquery_pathlist(PlannerInfo *root, RelOptInfo *rel, |
| Index rti, RangeTblEntry *rte); |
| static void set_function_pathlist(PlannerInfo *root, RelOptInfo *rel, |
| RangeTblEntry *rte); |
| static void set_tablefunction_pathlist(PlannerInfo *root, RelOptInfo *rel, |
| RangeTblEntry *rte); |
| static void set_values_pathlist(PlannerInfo *root, RelOptInfo *rel, |
| RangeTblEntry *rte); |
| static void set_cte_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte); |
| static RelOptInfo *make_rel_from_joinlist(PlannerInfo *root, List *joinlist); |
| static RelOptInfo *make_one_rel_by_joins(PlannerInfo *root, int levels_needed, |
| List *initial_rels, bool fallback); |
| static Query *push_down_restrict(PlannerInfo *root, RelOptInfo *rel, |
| RangeTblEntry *rte, Index rti, Query *subquery); |
| static bool subquery_is_pushdown_safe(Query *subquery, Query *topquery, |
| bool *differentTypes); |
| static bool recurse_pushdown_safe(Node *setOp, Query *topquery, |
| bool *differentTypes); |
| static void compare_tlist_datatypes(List *tlist, List *colTypes, |
| bool *differentTypes); |
| static bool qual_is_pushdown_safe(Query *subquery, Index rti, Node *qual, |
| bool *differentTypes); |
| static void subquery_push_qual(Query *subquery, |
| RangeTblEntry *rte, Index rti, Node *qual); |
| static void recurse_push_qual(Node *setOp, Query *topquery, |
| RangeTblEntry *rte, Index rti, Node *qual); |
| #ifdef _MSC_VER |
| __declspec(noreturn) |
| #endif |
| static void cdb_no_path_for_query(void) __attribute__((__noreturn__)); |
| |
| |
| /* |
| * make_one_rel |
| * Finds all possible access paths for executing a query, returning a |
| * single rel that represents the join of all base rels in the query. |
| */ |
| RelOptInfo * |
| make_one_rel(PlannerInfo *root, List *joinlist) |
| { |
| RelOptInfo *rel; |
| |
| /* |
| * Generate access paths for the base rels. |
| */ |
| set_base_rel_pathlists(root); |
| |
| /* |
| * CDB: If join, warn of any tables that need ANALYZE. |
| */ |
| if (has_multiple_baserels(root)) |
| { |
| Index rti; |
| RelOptInfo *brel; |
| RangeTblEntry *brte; |
| |
| for (rti = 1; rti < root->simple_rel_array_size; rti++) |
| { |
| brel = root->simple_rel_array[rti]; |
| if (brel && |
| brel->cdb_default_stats_used) |
| { |
| brte = rt_fetch(rti, root->parse->rtable); |
| cdb_default_stats_warning_for_table(brte->relid); |
| } |
| } |
| } |
| |
| /* |
| * Generate access paths for the entire join tree. |
| */ |
| rel = make_rel_from_joinlist(root, joinlist); |
| |
| /* CDB: No path might be found if user set enable_xxx = off */ |
| if (!rel || |
| !rel->cheapest_total_path) |
| cdb_no_path_for_query(); /* raise error - no return */ |
| |
| /* |
| * The result should join all and only the query's base rels. |
| */ |
| #ifdef USE_ASSERT_CHECKING |
| { |
| int num_base_rels = 0; |
| Index rti; |
| |
| for (rti = 1; rti < root->simple_rel_array_size; rti++) |
| { |
| RelOptInfo *brel = root->simple_rel_array[rti]; |
| |
| if (brel == NULL) |
| continue; |
| |
| Assert(brel->relid == rti); /* sanity check on array */ |
| |
| /* ignore RTEs that are "other rels" */ |
| if (brel->reloptkind != RELOPT_BASEREL) |
| continue; |
| |
| Assert(bms_is_member(rti, rel->relids)); |
| num_base_rels++; |
| } |
| |
| Assert(bms_num_members(rel->relids) == num_base_rels); |
| } |
| #endif |
| |
| return rel; |
| } |
| |
| /* |
| * set_base_rel_pathlists |
| * Finds all paths available for scanning each base-relation entry. |
| * Sequential scan and any available indices are considered. |
| * Each useful path is attached to its relation's 'pathlist' field. |
| */ |
| static void |
| set_base_rel_pathlists(PlannerInfo *root) |
| { |
| Index rti; |
| |
| for (rti = 1; rti < root->simple_rel_array_size; rti++) |
| { |
| RelOptInfo *rel = root->simple_rel_array[rti]; |
| |
| /* there may be empty slots corresponding to non-baserel RTEs */ |
| if (rel == NULL) |
| continue; |
| |
| Assert(rel->relid == rti); /* sanity check on array */ |
| |
| /* ignore RTEs that are "other rels" */ |
| if (rel->reloptkind != RELOPT_BASEREL) |
| continue; |
| |
| /* CDB: Warn if ctid column is referenced but gp_segment_id is not. */ |
| cdbmutate_warn_ctid_without_segid(root, rel); |
| |
| set_rel_pathlist(root, rel, rti); |
| } |
| } |
| |
| /* |
| * set_rel_pathlist |
| * Build access paths for a base relation |
| */ |
| static void |
| set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, Index rti) |
| { |
| RangeTblEntry *rte = rt_fetch(rti, root->parse->rtable); |
| |
| if (rte->inh) |
| { |
| /* It's an "append relation", process accordingly */ |
| set_append_rel_pathlist(root, rel, rti); |
| } |
| else if (rel->rtekind == RTE_SUBQUERY) |
| { |
| /* Subquery --- generate a separate plan for it */ |
| set_subquery_pathlist(root, rel, rti, rte); |
| } |
| else if (rel->rtekind == RTE_FUNCTION) |
| { |
| /* RangeFunction --- generate a separate plan for it */ |
| set_function_pathlist(root, rel, rte); |
| } |
| else if (rel->rtekind == RTE_TABLEFUNCTION) |
| { |
| /* RangeFunction --- generate a separate plan for it */ |
| set_tablefunction_pathlist(root, rel, rte); |
| } |
| else if (rel->rtekind == RTE_VALUES) |
| { |
| /* Values list --- generate a separate plan for it */ |
| set_values_pathlist(root, rel, rte); |
| } |
| else if (rel->rtekind == RTE_CTE) |
| { |
| set_cte_pathlist(root, rel, rte); |
| } |
| |
| else |
| { |
| /* Plain relation */ |
| Assert(rel->rtekind == RTE_RELATION); |
| set_plain_rel_pathlist(root, rel, rte); |
| } |
| |
| #ifdef OPTIMIZER_DEBUG |
| debug_print_rel(root, rel); |
| #endif |
| } |
| |
| /* |
| * set_plain_rel_pathlist |
| * Build access paths for a plain relation (no subquery, no inheritance) |
| */ |
| static void |
| set_plain_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte) |
| { |
| List *pathlist = NIL; |
| List *indexpathlist = NIL; |
| List *bitmappathlist = NIL; |
| List *tidpathlist = NIL; |
| Path *seqpath = NULL; |
| ListCell *cell; |
| char relstorage; |
| |
| /* Mark rel with estimated output rows, width, etc */ |
| set_baserel_size_estimates(root, rel); |
| |
| /* Test any partial indexes of rel for applicability */ |
| check_partial_indexes(root, rel); |
| |
| /* |
| * Check to see if we can extract any restriction conditions from join |
| * quals that are OR-of-AND structures. If so, add them to the rel's |
| * restriction list, and recompute the size estimates. |
| */ |
| if (create_or_index_quals(root, rel)) |
| set_baserel_size_estimates(root, rel); |
| |
| /* |
| * If we can prove we don't need to scan the rel via constraint exclusion, |
| * set up a single dummy path for it. (Rather than inventing a special |
| * "dummy" path type, we represent this as an AppendPath with no members.) |
| */ |
| if (relation_excluded_by_constraints(root, rel, rte)) |
| { |
| /* Reset output-rows estimate to 0 */ |
| rel->rows = 0; |
| |
| /* Obviously won't produce more than one row. */ |
| rel->onerow = true; |
| |
| add_path(root, rel, (Path *) create_append_path(root, rel, NIL)); |
| |
| /* Select cheapest path (pretty easy in this case...) */ |
| set_cheapest(root, rel); |
| |
| return; |
| } |
| |
| /* CDB: Attach subquery duplicate suppression info. */ |
| if (root->in_info_list) |
| rel->dedup_info = cdb_make_rel_dedup_info(root, rel); |
| |
| /* |
| * Generate paths and add them to the rel's pathlist. |
| * |
| * Note: add_path() will discard any paths that are dominated by another |
| * available path, keeping only those paths that are superior along at |
| * least one dimension of cost or sortedness. |
| * |
| * CDB: So that create_index_paths() and create_tidscan_paths() can set the |
| * rel->onerow flag before it is tested by add_path(), we gather the paths |
| * in a temporary list, then add them. |
| */ |
| |
| relstorage = get_rel_relstorage(rte->relid); |
| |
| /* early exit for external and append only relations */ |
| switch (relstorage) |
| { |
| case RELSTORAGE_EXTERNAL: |
| /* |
| * If the relation is external, create an external path for |
| * it and select it (only external path is considered for |
| * an external base rel). |
| */ |
| add_path(root, rel, (Path *) create_external_path(root, rel)); |
| set_cheapest(root, rel); |
| return; |
| |
| case RELSTORAGE_AOROWS: |
| seqpath = (Path *) create_appendonly_path(root, rel); |
| break; |
| |
| case RELSTORAGE_PARQUET: |
| seqpath = (Path *) create_parquet_path(root, rel); |
| break; |
| |
| case RELSTORAGE_HEAP: |
| seqpath = create_seqscan_path(root, rel); |
| break; |
| |
| default: |
| /* |
| * should not be feasible, usually indicates a failure to correctly |
| * apply rewrite rules. |
| */ |
| elog(ERROR, "plan contains range table with relstorage='%c'", relstorage); |
| return; |
| } |
| |
| /* Consider sequential scan. */ |
| if (root->config->enable_seqscan) |
| pathlist = lappend(pathlist, seqpath); |
| |
| /* Consider index and bitmap scans */ |
| create_index_paths(root, rel, relstorage, |
| &indexpathlist, &bitmappathlist); |
| |
| /* |
| * Random access to Append-Only is slow because AO doesn't use the buffer pool and |
| * we want to avoid decompressing blocks multiple times. So, only consider bitmap |
| * paths because they are processed in TID order. The appendonlyam.c module will |
| * optimize fetches in TID order by keeping the last decompressed block between fetch |
| * calls. |
| */ |
| if (relstorage == RELSTORAGE_AOROWS || |
| relstorage == RELSTORAGE_PARQUET) |
| indexpathlist = NIL; |
| |
| if (indexpathlist && root->config->enable_indexscan) |
| pathlist = list_concat(pathlist, indexpathlist); |
| if (bitmappathlist && root->config->enable_bitmapscan) |
| pathlist = list_concat(pathlist, bitmappathlist); |
| |
| /* Consider TID scans */ |
| create_tidscan_paths(root, rel, &tidpathlist); |
| |
| /* AO and CO tables do not currently support TidScans. Disable TidScan path for such tables */ |
| if (relstorage == RELSTORAGE_AOROWS || |
| relstorage == RELSTORAGE_PARQUET) |
| tidpathlist = NIL; |
| |
| if (tidpathlist && root->config->enable_tidscan) |
| pathlist = list_concat(pathlist, tidpathlist); |
| |
| /* If no enabled path was found, consider disabled paths. */ |
| if (!pathlist) |
| { |
| pathlist = lappend(pathlist, seqpath); |
| if (root->config->gp_enable_fallback_plan) |
| { |
| pathlist = list_concat(pathlist, indexpathlist); |
| pathlist = list_concat(pathlist, bitmappathlist); |
| pathlist = list_concat(pathlist, tidpathlist); |
| } |
| } |
| |
| /* Add them, now that we know whether the quals specify a unique key. */ |
| foreach(cell, pathlist) |
| add_path(root, rel, (Path *)lfirst(cell)); |
| |
| /* Now find the cheapest of the paths for this rel */ |
| set_cheapest(root, rel); |
| } |
| |
| /* |
| * set_append_rel_pathlist |
| * Build access paths for an "append relation" |
| * |
| * The passed-in rel and RTE represent the entire append relation. The |
| * relation's contents are computed by appending together the output of |
| * the individual member relations. Note that in the inheritance case, |
| * the first member relation is actually the same table as is mentioned in |
| * the parent RTE ... but it has a different RTE and RelOptInfo. This is |
| * a good thing because their outputs are not the same size. |
| */ |
| static void |
| set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, |
| Index rti) |
| { |
| Index parentRTindex = rti; |
| List *subpaths = NIL; |
| ListCell *l; |
| |
| /* weighted average of widths */ |
| double width_avg = 0; |
| |
| /* |
| * XXX for now, can't handle inherited expansion of FOR UPDATE/SHARE; can |
| * we do better? (This will take some redesign because the executor |
| * currently supposes that every rowMark relation is involved in every row |
| * returned by the query.) |
| */ |
| if (get_rowmark(root->parse, parentRTindex)) |
| ereport(ERROR, |
| (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), |
| errmsg("SELECT FOR UPDATE/SHARE is not supported for inheritance queries"))); |
| |
| /* Mark rel with estimated output rows, width, etc */ |
| set_baserel_size_estimates(root, rel); |
| |
| /* |
| * Initialize to compute size estimates for whole append relation |
| */ |
| rel->rows = 0; |
| rel->tuples = 0; |
| rel->width = 0; |
| |
| /* |
| * Generate access paths for each member relation, and pick the cheapest |
| * path for each one. |
| */ |
| foreach(l, root->append_rel_list) |
| { |
| AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l); |
| Index childRTindex; |
| RelOptInfo *childrel; |
| Path *childpath; |
| ListCell *parentvars; |
| ListCell *childvars; |
| |
| /* append_rel_list contains all append rels; ignore others */ |
| if (appinfo->parent_relid != parentRTindex) |
| continue; |
| |
| childRTindex = appinfo->child_relid; |
| |
| /* |
| * The child rel's RelOptInfo was already created during |
| * add_base_rels_to_query. |
| */ |
| childrel = find_base_rel(root, childRTindex); |
| Assert(childrel->reloptkind == RELOPT_OTHER_MEMBER_REL); |
| |
| /* |
| * Copy the parent's targetlist and quals to the child, with |
| * appropriate substitution of variables. |
| */ |
| childrel->reltargetlist = (List *) |
| adjust_appendrel_attrs(root, (Node *) rel->reltargetlist, |
| appinfo); |
| childrel->baserestrictinfo = (List *) |
| adjust_appendrel_attrs(root, (Node *) rel->baserestrictinfo, |
| appinfo); |
| childrel->joininfo = (List *) |
| adjust_appendrel_attrs(root, (Node *) rel->joininfo, |
| appinfo); |
| |
| /* |
| * Copy the parent's attr_needed data as well, with appropriate |
| * adjustment of relids and attribute numbers. |
| */ |
| pfree(childrel->attr_needed); |
| childrel->attr_needed = |
| adjust_appendrel_attr_needed(root, rel, appinfo, |
| childrel->min_attr, |
| childrel->max_attr); |
| |
| /* |
| * Compute the child's access paths, and add the cheapest one to the |
| * Append path we are constructing for the parent. |
| * |
| * It's possible that the child is itself an appendrel, in which case |
| * we can "cut out the middleman" and just add its child paths to our |
| * own list. (We don't try to do this earlier because we need to |
| * apply both levels of transformation to the quals.) This test also |
| * handles the case where the child rel need not be scanned because of |
| * constraint exclusion: it'll have an Append path with no subpaths, |
| * and will vanish from our list. |
| */ |
| set_rel_pathlist(root, childrel, childRTindex); |
| |
| childpath = childrel->cheapest_total_path; |
| if (IsA(childpath, AppendPath)) |
| subpaths = list_concat(subpaths, |
| ((AppendPath *) childpath)->subpaths); |
| else |
| subpaths = lappend(subpaths, childpath); |
| |
| |
| /* |
| * Propagate size information from the child back to the parent. For |
| * simplicity, we use the largest widths from any child as the parent |
| * estimates. |
| */ |
| rel->tuples += childrel->tuples; |
| rel->rows += cdbpath_rows(root, childrel->cheapest_total_path); |
| width_avg += cdbpath_rows(root, childrel->cheapest_total_path) * childrel->width; |
| |
| forboth(parentvars, rel->reltargetlist, |
| childvars, childrel->reltargetlist) |
| { |
| Var *parentvar = (Var *) lfirst(parentvars); |
| Var *childvar = (Var *) lfirst(childvars); |
| |
| if (IsA(parentvar, Var) && |
| IsA(childvar, Var)) |
| { |
| int pndx = parentvar->varattno - rel->min_attr; |
| int cndx = childvar->varattno - childrel->min_attr; |
| |
| if (childrel->attr_widths[cndx] > rel->attr_widths[pndx]) |
| rel->attr_widths[pndx] = childrel->attr_widths[cndx]; |
| } |
| } |
| } |
| |
| rel->width = (int) (width_avg / Max(1.0, rel->rows)); |
| |
| /* CDB: Just one child (or none)? Set flag if result is at most 1 row. */ |
| if (!subpaths) |
| rel->onerow = true; |
| else if (list_length(subpaths) == 1) |
| rel->onerow = ((Path *)linitial(subpaths))->parent->onerow; |
| |
| /* |
| * Set "raw tuples" count equal to "rows" for the appendrel; needed |
| * because some places assume rel->tuples is valid for any baserel. |
| * |
| * CDB: Already set rel->tuples accurately above. |
| */ |
| /* rel->tuples = rel->rows; */ |
| |
| /* |
| * Finally, build Append path and install it as the only access path for |
| * the parent rel. (Note: this is correct even if we have zero or one |
| * live subpath due to constraint exclusion.) |
| */ |
| add_path(root, rel, (Path *) create_append_path(root, rel, subpaths)); |
| |
| /* Select cheapest path (pretty easy in this case...) */ |
| set_cheapest(root, rel); |
| } |
| |
| /* quick-and-dirty test to see if any joining is needed */ |
| static bool |
| has_multiple_baserels(PlannerInfo *root) |
| { |
| int num_base_rels = 0; |
| Index rti; |
| |
| for (rti = 1; rti < root->simple_rel_array_size; rti++) |
| { |
| RelOptInfo *brel = root->simple_rel_array[rti]; |
| |
| if (brel == NULL) |
| continue; |
| |
| /* ignore RTEs that are "other rels" */ |
| if (brel->reloptkind == RELOPT_BASEREL) |
| if (++num_base_rels > 1) |
| return true; |
| } |
| return false; |
| } |
| |
| /* |
| * set_subquery_pathlist |
| * Build the (single) access path for a subquery RTE |
| */ |
| static void |
| set_subquery_pathlist(PlannerInfo *root, RelOptInfo *rel, |
| Index rti, RangeTblEntry *rte) |
| { |
| Query *subquery = rte->subquery; |
| double tuple_fraction; |
| List *pathkeys; |
| PlannerInfo *subroot; |
| List *subquery_pathkeys; |
| bool forceDistRand; |
| Path *subquery_path; |
| |
| forceDistRand = rte->forceDistRandom; |
| |
| /* CDB: Could be a preplanned subquery from window_planner. */ |
| if ( rte->subquery_plan == NULL ) |
| { |
| /* |
| * push down quals if possible. Note subquery might be |
| * different pointer from original one. |
| */ |
| subquery = push_down_restrict(root, rel, rte, rti, subquery); |
| |
| /* |
| * CDB: Does the subquery return at most one row? |
| */ |
| rel->onerow = false; |
| |
| /* Set-returning function in tlist could give any number of rows. */ |
| if (expression_returns_set((Node *)subquery->targetList)) |
| {} |
| |
| /* Always one row if aggregate function without GROUP BY. */ |
| else if (!subquery->groupClause && |
| (subquery->hasAggs || subquery->havingQual)) |
| rel->onerow = true; |
| |
| /* LIMIT 1 or less? */ |
| else if (subquery->limitCount && |
| IsA(subquery->limitCount, Const) && |
| !((Const *)subquery->limitCount)->constisnull) |
| { |
| Const *cnst = (Const *)subquery->limitCount; |
| |
| if (cnst->consttype == INT8OID && |
| DatumGetInt64(cnst->constvalue) <= 1) |
| rel->onerow = true; |
| } |
| |
| /* |
| * We can safely pass the outer tuple_fraction down to the subquery if the |
| * outer level has no joining, aggregation, or sorting to do. Otherwise |
| * we'd better tell the subquery to plan for full retrieval. (XXX This |
| * could probably be made more intelligent ...) |
| */ |
| if (subquery->hasAggs || |
| subquery->groupClause || |
| subquery->havingQual || |
| subquery->distinctClause || |
| subquery->sortClause || |
| has_multiple_baserels(root)) |
| tuple_fraction = 0.0; /* default case */ |
| else |
| tuple_fraction = root->tuple_fraction; |
| |
| /* Generate the plan for the subquery */ |
| PlannerConfig *config = CopyPlannerConfig(root->config); |
| |
| rel->subplan = subquery_planner(root->glob, subquery, root, tuple_fraction, |
| &subroot, config); |
| rel->subrtable = subroot->parse->rtable; |
| subquery_pathkeys = subroot->query_pathkeys; |
| } |
| else |
| { |
| /* This is a preplanned sub-query RTE. */ |
| rel->subplan = rte->subquery_plan; |
| rel->subrtable = rte->subquery_rtable; |
| subquery_pathkeys = rte->subquery_pathkeys; |
| /* XXX rel->onerow = ??? */ |
| } |
| |
| /* Copy number of output rows from subplan */ |
| if (rel->onerow) |
| rel->tuples = 1; |
| else |
| rel->tuples = rel->subplan->plan_rows; |
| |
| /* CDB: Attach subquery duplicate suppression info. */ |
| if (root->in_info_list) |
| rel->dedup_info = cdb_make_rel_dedup_info(root, rel); |
| |
| /* Mark rel with estimated output rows, width, etc */ |
| set_baserel_size_estimates(root, rel); |
| |
| /* Convert subquery pathkeys to outer representation */ |
| pathkeys = convert_subquery_pathkeys(root, rel, subquery_pathkeys); |
| |
| /* Generate appropriate path */ |
| subquery_path = create_subqueryscan_path(root, rel, pathkeys); |
| |
| if (forceDistRand) |
| CdbPathLocus_MakeStrewn(&subquery_path->locus); |
| |
| add_path(root, rel, subquery_path); |
| |
| /* Select cheapest path (pretty easy in this case...) */ |
| set_cheapest(root, rel); |
| } |
| |
| /* |
| * set_cte_pathlist |
| * Buld the (single) access path for a CTE RTE. |
| */ |
| static |
| void set_cte_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte) |
| { |
| /* Find the referenced CTE based on the given range table entry */ |
| Index levelsup = rte->ctelevelsup; |
| PlannerInfo *cteroot = root; |
| while (levelsup > 0) |
| { |
| cteroot = cteroot->parent_root; |
| Assert(cteroot != NULL); |
| levelsup--; |
| } |
| |
| ListCell *lc; |
| CommonTableExpr *cte = NULL; |
| int planinfo_id = 0; |
| foreach(lc, cteroot->parse->cteList) |
| { |
| cte = (CommonTableExpr *) lfirst(lc); |
| |
| if (strcmp(cte->ctename, rte->ctename) == 0) |
| break; |
| planinfo_id++; |
| } |
| |
| Assert(lc != NULL); |
| Assert(cte != NULL); |
| |
| double tuple_fraction = 0.0; |
| Assert(IsA(cte->ctequery, Query)); |
| |
| /* |
| * Determine whether we need to generate a new subplan for this CTE. |
| * |
| * There are the following cases: |
| * (1) If this subquery can be pulled up as an InitPlan, we will |
| * generate a new subplan. In InitPlan case, the subplan can |
| * not be shared with the main query or other InitPlans. We |
| * do not store this subplan in cteplaninfo. |
| * (2) If we never generate a subplan for this CTE, then we generate |
| * one. If the reference count for this CTE is greater than 1 |
| * (excluding ones used in InitPlans), we create multiple subplans, |
| * each of which has a SharedNode on top. We store these subplans |
| * in cteplaninfo so that they can be used later. |
| */ |
| Assert(list_length(cteroot->list_cteplaninfo) > planinfo_id); |
| CtePlanInfo *cteplaninfo = list_nth(cteroot->list_cteplaninfo, planinfo_id); |
| |
| Plan *subplan = NULL; |
| List *subrtable = NULL; |
| List *pathkeys = NULL; |
| PlannerInfo *subroot = NULL; |
| |
| /* If sharing is not allowed, we create a new subplan for this CTE. */ |
| if (!root->config->gp_cte_sharing) |
| { |
| PlannerConfig *config = CopyPlannerConfig(root->config); |
| |
| /** |
| * Copy query node since subquery_planner may trash it and we need it intact |
| * in case we need to create another plan for the CTE |
| */ |
| Query *subquery = (Query *) copyObject(cte->ctequery); |
| |
| /** |
| * Push down quals |
| */ |
| subquery = push_down_restrict(root, rel, rte, rel->relid, subquery); |
| |
| subplan = subquery_planner(cteroot->glob, subquery, cteroot, |
| tuple_fraction, &subroot, config); |
| cteplaninfo->numNonSharedPlans++; |
| |
| subrtable = subroot->parse->rtable; |
| pathkeys = subroot->query_pathkeys; |
| |
| /* |
| * Do not store the subplan in cteplaninfo, since we will not share |
| * this plan. |
| */ |
| } |
| |
| /* |
| * If we never generate a subplan for this CTE, generate one here. |
| * This subplan will not be used by InitPlans, so that they can be |
| * shared if this CTE is referenced multiple times (excluding in InitPlans). |
| * We also generate all shared plans here. |
| */ |
| else if (cteplaninfo->subplans == NULL) |
| { |
| PlannerConfig *config = CopyPlannerConfig(root->config); |
| |
| /** |
| * Having multiple SharedScans can lead to deadlocks. For now, |
| * disallow sharing of ctes at lower levels. |
| */ |
| config->gp_cte_sharing = false; |
| /** |
| * Copy query node since subquery_planner may trash it and we need it intact |
| * in case we need to create another plan for the CTE |
| */ |
| |
| Query *subquery = (Query *) copyObject(cte->ctequery); |
| |
| if ((cte->cterefcount - cteplaninfo->numNonSharedPlans) == 1) |
| { |
| /* |
| * If this CTE is referenced only once, |
| * it will become simple subquery scan. |
| * In that case, we can push down quals in the same way |
| * as set_subqeury_pathlist(). |
| * |
| * subquery tree will be modified if any qual is pushed down. |
| * There's risk that it'd be confusing if the tree is used |
| * later. At the moment InitPlan case uses the tree, but it |
| * is called earlier than this pass always, so we don't avoid it. |
| * |
| * Also, we might want to think extracting "common" |
| * qual expressions between multiple references, but |
| * so far we don't support it. |
| */ |
| subquery = push_down_restrict(root, rel, rte, rel->relid, subquery); |
| } |
| subplan = subquery_planner(cteroot->glob, subquery, cteroot, |
| tuple_fraction, &subroot, config); |
| |
| List *subplans = share_plan(cteroot, subplan, |
| cte->cterefcount); |
| |
| cteplaninfo->subplans = subplans; |
| cteplaninfo->subrtable = subroot->parse->rtable; |
| cteplaninfo->pathkeys = subroot->query_pathkeys; |
| cteplaninfo->nextPlanId = 0; |
| |
| subplan = list_nth(cteplaninfo->subplans, cteplaninfo->nextPlanId); |
| cteplaninfo->nextPlanId++; |
| |
| subrtable = subroot->parse->rtable; |
| pathkeys = subroot->query_pathkeys; |
| } |
| |
| /* |
| * The subplan has been generated in advance (see the above). We simply find |
| * the subplan in the list stored in cteplaninfo. |
| */ |
| else |
| { |
| Assert(root->config->gp_cte_sharing && cteplaninfo->subplans != NULL); |
| Assert(cteplaninfo->nextPlanId < list_length(cteplaninfo->subplans)); |
| subplan = list_nth(cteplaninfo->subplans, cteplaninfo->nextPlanId); |
| subrtable = cteplaninfo->subrtable; |
| pathkeys = cteplaninfo->pathkeys; |
| cteplaninfo->nextPlanId++; |
| } |
| |
| rel->subplan = subplan; |
| rel->subrtable = subrtable; |
| |
| /* Mark rel with estimated output rows, width, etc */ |
| set_cte_size_estimates(root, rel, rel->subplan); |
| |
| /* Convert subquery pathkeys to outer representation */ |
| pathkeys = convert_subquery_pathkeys(root, rel, pathkeys); |
| |
| /* Generate appropriate path */ |
| add_path(root, rel, create_ctescan_path(root, rel, pathkeys)); |
| |
| /* Select cheapest path (pretty easy in this case...) */ |
| set_cheapest(root, rel); |
| } |
| |
| |
| /* |
| * set_function_pathlist |
| * Build the (single) access path for a function RTE |
| */ |
| static void |
| set_function_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte) |
| { |
| /* CDB: Could the function return more than one row? */ |
| rel->onerow = !expression_returns_set(rte->funcexpr); |
| |
| /* CDB: Attach subquery duplicate suppression info. */ |
| if (root->in_info_list) |
| rel->dedup_info = cdb_make_rel_dedup_info(root, rel); |
| |
| /* Mark rel with estimated output rows, width, etc */ |
| set_function_size_estimates(root, rel); |
| |
| /* Generate appropriate path */ |
| add_path(root, rel, create_functionscan_path(root, rel, rte)); |
| |
| /* Select cheapest path (pretty easy in this case...) */ |
| set_cheapest(root, rel); |
| } |
| |
| /* |
| * set_tablefunction_pathlist |
| * Build the (single) access path for a table function RTE |
| */ |
| static void |
| set_tablefunction_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte) |
| { |
| PlannerConfig *config = CopyPlannerConfig(root->config); |
| PlannerInfo *subroot = NULL; |
| FuncExpr *fexpr = (FuncExpr *) rte->funcexpr; |
| ListCell *arg; |
| |
| /* Cannot be a preplanned subquery from window_planner. */ |
| Assert(!rte->subquery_plan); |
| Assert(fexpr && IsA(fexpr, FuncExpr)); |
| |
| /* Plan input subquery */ |
| rel->subplan = subquery_planner( root->glob, rte->subquery, root, |
| 0.0, // tuple_fraction |
| &subroot, |
| config ); |
| rel->subrtable = subroot->parse->rtable; |
| |
| /* |
| * With the subquery planned we now need to clear the subquery from the |
| * TableValueExpr nodes, otherwise preprocess_expression will trip over it. |
| */ |
| foreach(arg, fexpr->args) |
| { |
| if (IsA(arg, TableValueExpr)) |
| { |
| TableValueExpr *tve = (TableValueExpr *) arg; |
| tve->subquery = NULL; |
| } |
| } |
| |
| /* Could the function return more than one row? */ |
| rel->onerow = !expression_returns_set(rte->funcexpr); |
| |
| /* Attach subquery duplicate suppression info. */ |
| if (root->in_info_list) |
| rel->dedup_info = cdb_make_rel_dedup_info(root, rel); |
| |
| /* Mark rel with estimated output rows, width, etc */ |
| set_table_function_size_estimates(root, rel); |
| |
| /* Generate appropriate path */ |
| add_path(root, rel, create_tablefunction_path(root, rel, rte)); |
| |
| /* Select cheapest path (pretty easy in this case...) */ |
| set_cheapest(root, rel); |
| } |
| |
| /* |
| * set_values_pathlist |
| * Build the (single) access path for a VALUES RTE |
| */ |
| static void |
| set_values_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte) |
| { |
| /* Mark rel with estimated output rows, width, etc */ |
| set_values_size_estimates(root, rel); |
| |
| /* CDB: Just one row? */ |
| rel->onerow = (rel->tuples <= 1 && |
| !expression_returns_set((Node *)rte->values_lists)); |
| |
| /* CDB: Attach subquery duplicate suppression info. */ |
| if (root->in_info_list) |
| rel->dedup_info = cdb_make_rel_dedup_info(root, rel); |
| |
| /* Generate appropriate path */ |
| add_path(root, rel, create_valuesscan_path(root, rel, rte)); |
| |
| /* Select cheapest path (pretty easy in this case...) */ |
| set_cheapest(root, rel); |
| } |
| |
| /* |
| * make_rel_from_joinlist |
| * Build access paths using a "joinlist" to guide the join path search. |
| * |
| * See comments for deconstruct_jointree() for definition of the joinlist |
| * data structure. |
| */ |
| static RelOptInfo * |
| make_rel_from_joinlist(PlannerInfo *root, List *joinlist) |
| { |
| int levels_needed; |
| List *initial_rels; |
| ListCell *jl; |
| |
| /* |
| * Count the number of child joinlist nodes. This is the depth of the |
| * dynamic-programming algorithm we must employ to consider all ways of |
| * joining the child nodes. |
| */ |
| levels_needed = list_length(joinlist); |
| |
| if (levels_needed <= 0) |
| return NULL; /* nothing to do? */ |
| |
| /* |
| * Construct a list of rels corresponding to the child joinlist nodes. |
| * This may contain both base rels and rels constructed according to |
| * sub-joinlists. |
| */ |
| initial_rels = NIL; |
| foreach(jl, joinlist) |
| { |
| Node *jlnode = (Node *) lfirst(jl); |
| RelOptInfo *thisrel; |
| |
| if (IsA(jlnode, RangeTblRef)) |
| { |
| int varno = ((RangeTblRef *) jlnode)->rtindex; |
| |
| thisrel = find_base_rel(root, varno); |
| } |
| else if (IsA(jlnode, List)) |
| { |
| /* Recurse to handle subproblem */ |
| thisrel = make_rel_from_joinlist(root, (List *) jlnode); |
| } |
| else |
| { |
| elog(ERROR, "unrecognized joinlist node type: %d", |
| (int) nodeTag(jlnode)); |
| thisrel = NULL; /* keep compiler quiet */ |
| } |
| |
| /* CDB: Fail if no path could be built due to set enable_xxx = off. */ |
| if (!thisrel || |
| !thisrel->cheapest_total_path) |
| return NULL; |
| |
| initial_rels = lappend(initial_rels, thisrel); |
| } |
| |
| if (levels_needed == 1) |
| { |
| /* |
| * Single joinlist node, so we're done. |
| */ |
| return (RelOptInfo *) linitial(initial_rels); |
| } |
| else |
| { |
| /* |
| * Consider the different orders in which we could join the rels, |
| * using either GEQO or regular optimizer. |
| * |
| * We put the initial_rels list into a PlannerInfo field because |
| * has_legal_joinclause() needs to look at it (ugly :-(). |
| */ |
| RelOptInfo *rel; |
| root->initial_rels = initial_rels; |
| |
| rel = make_one_rel_by_joins(root, levels_needed, initial_rels, false); |
| |
| if (rel == NULL |
| && root->config->gp_enable_fallback_plan) |
| { |
| root->join_rel_hash = NULL; |
| root->join_rel_list = NULL; |
| rel = make_one_rel_by_joins(root, levels_needed, initial_rels, true); |
| } |
| return rel; |
| } |
| } |
| |
| /* |
| * make_one_rel_by_joins |
| * Find all possible joinpaths for a query by successively finding ways |
| * to join component relations into join relations. |
| * |
| * 'levels_needed' is the number of iterations needed, ie, the number of |
| * independent jointree items in the query. This is > 1. |
| * |
| * 'initial_rels' is a list of RelOptInfo nodes for each independent |
| * jointree item. These are the components to be joined together. |
| * |
| * Returns the final level of join relations, i.e., the relation that is |
| * the result of joining all the original relations together. |
| */ |
| static RelOptInfo * |
| make_one_rel_by_joins(PlannerInfo *root, int levels_needed, List *initial_rels, bool fallback) |
| { |
| List **joinitems = NULL; |
| int lev; |
| RelOptInfo *rel = NULL; |
| |
| root->config->mpp_trying_fallback_plan = fallback; |
| |
| /* |
| * We employ a simple "dynamic programming" algorithm: we first find all |
| * ways to build joins of two jointree items, then all ways to build joins |
| * of three items (from two-item joins and single items), then four-item |
| * joins, and so on until we have considered all ways to join all the |
| * items into one rel. |
| * |
| * joinitems[j] is a list of all the j-item rels. Initially we set |
| * joinitems[1] to represent all the single-jointree-item relations. |
| */ |
| joinitems = (List **) palloc0((levels_needed + 1) * sizeof(List *)); |
| |
| joinitems[1] = initial_rels; |
| |
| for (lev = 2; lev <= levels_needed; lev++) |
| { |
| ListCell *w = NULL; |
| ListCell *x; |
| ListCell *y; |
| |
| /* |
| * Determine all possible pairs of relations to be joined at this |
| * level, and build paths for making each one from every available |
| * pair of lower-level relations. |
| */ |
| joinitems[lev] = make_rels_by_joins(root, lev, joinitems); |
| |
| /* |
| * Do cleanup work on each just-processed rel. |
| */ |
| for (x = list_head(joinitems[lev]); x; x = y) /* cannot use foreach */ |
| { |
| y = lnext(x); |
| rel = (RelOptInfo *) lfirst(x); |
| |
| /* Find and save the cheapest paths for this rel */ |
| set_cheapest(root, rel); |
| |
| /* CDB: Prune this rel if it has no path. */ |
| if (!rel->cheapest_total_path) |
| joinitems[lev] = list_delete_cell(joinitems[lev], x, w); |
| |
| /* Keep this rel. */ |
| else |
| w = x; |
| |
| #ifdef OPTIMIZER_DEBUG |
| debug_print_rel(root, rel); |
| #endif |
| } |
| /* If no paths found because enable_xxx=false, enable all & retry. */ |
| if (!joinitems[lev] && |
| root->config->gp_enable_fallback_plan && |
| !root->config->mpp_trying_fallback_plan) |
| { |
| root->config->mpp_trying_fallback_plan = true; |
| lev--; |
| } |
| |
| } |
| |
| /* |
| * We should have a single rel at the final level. |
| */ |
| if (joinitems[levels_needed] == NIL) |
| return NULL; |
| Assert(list_length(joinitems[levels_needed]) == 1); |
| |
| rel = (RelOptInfo *) linitial(joinitems[levels_needed]); |
| |
| return rel; |
| } |
| |
| /***************************************************************************** |
| * PUSHING QUALS DOWN INTO SUBQUERIES |
| *****************************************************************************/ |
| |
| /* |
| * push_down_restrict |
| * push down restrictinfo to subquery if any. |
| * |
| * If there are any restriction clauses that have been attached to the |
| * subquery relation, consider pushing them down to become WHERE or HAVING |
| * quals of the subquery itself. This transformation is useful because it |
| * may allow us to generate a better plan for the subquery than evaluating |
| * all the subquery output rows and then filtering them. |
| * |
| * There are several cases where we cannot push down clauses. Restrictions |
| * involving the subquery are checked by subquery_is_pushdown_safe(). |
| * Restrictions on individual clauses are checked by |
| * qual_is_pushdown_safe(). Also, we don't want to push down |
| * pseudoconstant clauses; better to have the gating node above the |
| * subquery. |
| * |
| * Non-pushed-down clauses will get evaluated as qpquals of the |
| * SubqueryScan node. |
| * |
| * XXX Are there any cases where we want to make a policy decision not to |
| * push down a pushable qual, because it'd result in a worse plan? |
| */ |
| static Query * |
| push_down_restrict(PlannerInfo *root, RelOptInfo *rel, |
| RangeTblEntry *rte, Index rti, Query *subquery) |
| { |
| bool *differentTypes; |
| |
| /* Nothing to do here if it doesn't have qual at all */ |
| if (rel->baserestrictinfo == NIL) |
| return subquery; |
| |
| /* We need a workspace for keeping track of set-op type coercions */ |
| differentTypes = (bool *) |
| palloc0((list_length(subquery->targetList) + 1) * sizeof(bool)); |
| |
| if (subquery_is_pushdown_safe(subquery, subquery, differentTypes)) |
| { |
| /* Ok to consider pushing down individual quals */ |
| List *upperrestrictlist = NIL; |
| ListCell *l; |
| |
| foreach(l, rel->baserestrictinfo) |
| { |
| RestrictInfo *rinfo = (RestrictInfo *) lfirst(l); |
| Node *clause = (Node *) rinfo->clause; |
| |
| if (!rinfo->pseudoconstant && |
| qual_is_pushdown_safe(subquery, rti, clause, differentTypes)) |
| { |
| /* Push it down */ |
| subquery_push_qual(subquery, rte, rti, clause); |
| } |
| else |
| { |
| /* Keep it in the upper query */ |
| upperrestrictlist = lappend(upperrestrictlist, rinfo); |
| } |
| } |
| rel->baserestrictinfo = upperrestrictlist; |
| } |
| |
| pfree(differentTypes); |
| |
| return subquery; |
| } |
| |
| /* |
| * subquery_is_pushdown_safe - is a subquery safe for pushing down quals? |
| * |
| * subquery is the particular component query being checked. topquery |
| * is the top component of a set-operations tree (the same Query if no |
| * set-op is involved). |
| * |
| * Conditions checked here: |
| * |
| * 1. If the subquery has a LIMIT clause, we must not push down any quals, |
| * since that could change the set of rows returned. |
| * |
| * 2. If the subquery contains EXCEPT or EXCEPT ALL set ops we cannot push |
| * quals into it, because that would change the results. |
| * |
| * 3. For subqueries using UNION/UNION ALL/INTERSECT/INTERSECT ALL, we can |
| * push quals into each component query, but the quals can only reference |
| * subquery columns that suffer no type coercions in the set operation. |
| * Otherwise there are possible semantic gotchas. So, we check the |
| * component queries to see if any of them have different output types; |
| * differentTypes[k] is set true if column k has different type in any |
| * component. |
| * |
| * 4. If the subquery target list has expressions containing calls to |
| * window functions, we must not push down any quals since this could |
| * change the meaning of the query. At runtime, window functions refer |
| * to the executor state of their Window node. If a pushed-down qual |
| * removed a tuple, the state seen by later tuples (hence the values |
| * of window functions) could be affected. |
| * |
| * 5. Do not push down quals if the subquery is a grouping extension |
| * query, since this may change the meaning of the query. |
| */ |
| static bool |
| subquery_is_pushdown_safe(Query *subquery, Query *topquery, |
| bool *differentTypes) |
| { |
| SetOperationStmt *topop; |
| |
| /* Check point 1 */ |
| if (subquery->limitOffset != NULL || subquery->limitCount != NULL) |
| return false; |
| |
| /* Targetlist must not contain SRF */ |
| if ( expression_returns_set((Node *) subquery->targetList)) |
| return false; |
| |
| /* See point 5. */ |
| if (subquery->groupClause != NULL && |
| contain_extended_grouping(subquery->groupClause)) |
| return false; |
| |
| /* Are we at top level, or looking at a setop component? */ |
| if (subquery == topquery) |
| { |
| /* Top level, so check any component queries */ |
| if (subquery->setOperations != NULL) |
| if (!recurse_pushdown_safe(subquery->setOperations, topquery, |
| differentTypes)) |
| return false; |
| } |
| else |
| { |
| /* Setop component must not have more components (too weird) */ |
| if (subquery->setOperations != NULL) |
| return false; |
| /* Check whether setop component output types match top level */ |
| topop = (SetOperationStmt *) topquery->setOperations; |
| Assert(topop && IsA(topop, SetOperationStmt)); |
| compare_tlist_datatypes(subquery->targetList, |
| topop->colTypes, |
| differentTypes); |
| } |
| return true; |
| } |
| |
| /* |
| * Helper routine to recurse through setOperations tree |
| */ |
| static bool |
| recurse_pushdown_safe(Node *setOp, Query *topquery, |
| bool *differentTypes) |
| { |
| if (IsA(setOp, RangeTblRef)) |
| { |
| RangeTblRef *rtr = (RangeTblRef *) setOp; |
| RangeTblEntry *rte = rt_fetch(rtr->rtindex, topquery->rtable); |
| Query *subquery = rte->subquery; |
| |
| Assert(subquery != NULL); |
| return subquery_is_pushdown_safe(subquery, topquery, differentTypes); |
| } |
| else if (IsA(setOp, SetOperationStmt)) |
| { |
| SetOperationStmt *op = (SetOperationStmt *) setOp; |
| |
| /* EXCEPT is no good */ |
| if (op->op == SETOP_EXCEPT) |
| return false; |
| /* Else recurse */ |
| if (!recurse_pushdown_safe(op->larg, topquery, differentTypes)) |
| return false; |
| if (!recurse_pushdown_safe(op->rarg, topquery, differentTypes)) |
| return false; |
| } |
| else |
| { |
| elog(ERROR, "unrecognized node type: %d", |
| (int) nodeTag(setOp)); |
| } |
| return true; |
| } |
| |
| /* |
| * Compare tlist's datatypes against the list of set-operation result types. |
| * For any items that are different, mark the appropriate element of |
| * differentTypes[] to show that this column will have type conversions. |
| * |
| * We don't have to care about typmods here: the only allowed difference |
| * between set-op input and output typmods is input is a specific typmod |
| * and output is -1, and that does not require a coercion. |
| */ |
| static void |
| compare_tlist_datatypes(List *tlist, List *colTypes, |
| bool *differentTypes) |
| { |
| ListCell *l; |
| ListCell *colType = list_head(colTypes); |
| |
| foreach(l, tlist) |
| { |
| TargetEntry *tle = (TargetEntry *) lfirst(l); |
| |
| if (tle->resjunk) |
| continue; /* ignore resjunk columns */ |
| if (colType == NULL) |
| elog(ERROR, "wrong number of tlist entries"); |
| if (exprType((Node *) tle->expr) != lfirst_oid(colType)) |
| differentTypes[tle->resno] = true; |
| colType = lnext(colType); |
| } |
| if (colType != NULL) |
| elog(ERROR, "wrong number of tlist entries"); |
| } |
| |
| /* |
| * qual_is_pushdown_safe - is a particular qual safe to push down? |
| * |
| * qual is a restriction clause applying to the given subquery (whose RTE |
| * has index rti in the parent query). |
| * |
| * Conditions checked here: |
| * |
| * 1. The qual must not contain any subselects (mainly because I'm not sure |
| * it will work correctly: sublinks will already have been transformed into |
| * subplans in the qual, but not in the subquery). |
| * |
| * 2. The qual must not refer to the whole-row output of the subquery |
| * (since there is no easy way to name that within the subquery itself). |
| * |
| * 3. The qual must not refer to any subquery output columns that were |
| * found to have inconsistent types across a set operation tree by |
| * subquery_is_pushdown_safe(). |
| * |
| * 4. If the subquery uses DISTINCT ON, we must not push down any quals that |
| * refer to non-DISTINCT output columns, because that could change the set |
| * of rows returned. This condition is vacuous for DISTINCT, because then |
| * there are no non-DISTINCT output columns, but unfortunately it's fairly |
| * expensive to tell the difference between DISTINCT and DISTINCT ON in the |
| * parsetree representation. It's cheaper to just make sure all the Vars |
| * in the qual refer to DISTINCT columns. |
| * |
| * 5. We must not push down any quals that refer to subselect outputs that |
| * return sets, else we'd introduce functions-returning-sets into the |
| * subquery's WHERE/HAVING quals. |
| * |
| * 6. We must not push down any quals that refer to subselect outputs that |
| * contain volatile functions, for fear of introducing strange results due |
| * to multiple evaluation of a volatile function. |
| */ |
| static bool |
| qual_is_pushdown_safe(Query *subquery, Index rti, Node *qual, |
| bool *differentTypes) |
| { |
| bool safe = true; |
| List *vars; |
| ListCell *vl; |
| Bitmapset *tested = NULL; |
| |
| /* Refuse subselects (point 1) */ |
| if (contain_subplans(qual)) |
| return false; |
| |
| /* |
| * Examine all Vars used in clause; since it's a restriction clause, all |
| * such Vars must refer to subselect output columns. |
| */ |
| vars = pull_var_clause(qual, false); |
| foreach(vl, vars) |
| { |
| Var *var = (Var *) lfirst(vl); |
| TargetEntry *tle; |
| |
| Assert(var->varno == rti); |
| |
| /* Check point 2 */ |
| if (var->varattno == 0) |
| { |
| safe = false; |
| break; |
| } |
| |
| /* |
| * We use a bitmapset to avoid testing the same attno more than once. |
| * (NB: this only works because subquery outputs can't have negative |
| * attnos.) |
| */ |
| if (bms_is_member(var->varattno, tested)) |
| continue; |
| tested = bms_add_member(tested, var->varattno); |
| |
| /* Check point 3 */ |
| if (differentTypes[var->varattno]) |
| { |
| safe = false; |
| break; |
| } |
| |
| /* Must find the tlist element referenced by the Var */ |
| tle = get_tle_by_resno(subquery->targetList, var->varattno); |
| Assert(tle != NULL); |
| Assert(!tle->resjunk); |
| |
| /* If subquery uses DISTINCT or DISTINCT ON, check point 4 */ |
| if (subquery->distinctClause != NIL && |
| !targetIsInSortGroupList(tle, subquery->distinctClause)) |
| { |
| /* non-DISTINCT column, so fail */ |
| safe = false; |
| break; |
| } |
| |
| /* Refuse functions returning sets (point 5) */ |
| if (expression_returns_set((Node *) tle->expr)) |
| { |
| safe = false; |
| break; |
| } |
| |
| /* Refuse volatile functions (point 6) */ |
| if (contain_volatile_functions((Node *) tle->expr)) |
| { |
| safe = false; |
| break; |
| } |
| |
| /* Refuse subplans */ |
| if (contain_subplans((Node *) tle->expr)) |
| { |
| safe = false; |
| break; |
| } |
| |
| /* MPP-19244: |
| * if subquery has WINDOW clause, it is safe to push-down quals that |
| * use columns included in in the Partition-By clauses of every OVER |
| * clause in the subquery |
| * */ |
| if (subquery->windowClause != NIL) |
| { |
| ListCell *lc = NULL; |
| foreach(lc, subquery->windowClause) |
| { |
| WindowSpec *ws = (WindowSpec *) lfirst(lc); |
| if (!targetIsInSortGroupList(tle, ws->partition)) |
| { |
| /* qual's columns are not included in Partition-By clause, so fail */ |
| safe = false; |
| break; |
| } |
| } |
| } |
| |
| } |
| |
| list_free(vars); |
| bms_free(tested); |
| |
| return safe; |
| } |
| |
| /* |
| * subquery_push_qual - push down a qual that we have determined is safe |
| */ |
| static void |
| subquery_push_qual(Query *subquery, RangeTblEntry *rte, Index rti, Node *qual) |
| { |
| if (subquery->setOperations != NULL) |
| { |
| /* Recurse to push it separately to each component query */ |
| recurse_push_qual(subquery->setOperations, subquery, |
| rte, rti, qual); |
| } |
| else |
| { |
| /* |
| * We need to replace Vars in the qual (which must refer to outputs of |
| * the subquery) with copies of the subquery's targetlist expressions. |
| * Note that at this point, any uplevel Vars in the qual should have |
| * been replaced with Params, so they need no work. |
| * |
| * This step also ensures that when we are pushing into a setop tree, |
| * each component query gets its own copy of the qual. |
| */ |
| qual = ResolveNew(qual, rti, 0, rte, |
| subquery->targetList, |
| CMD_SELECT, 0); |
| |
| /* |
| * Now attach the qual to the proper place: normally WHERE, but if the |
| * subquery uses grouping or aggregation, put it in HAVING (since the |
| * qual really refers to the group-result rows). |
| */ |
| if (subquery->hasAggs || subquery->groupClause || subquery->havingQual) |
| subquery->havingQual = make_and_qual(subquery->havingQual, qual); |
| else |
| subquery->jointree->quals = |
| make_and_qual(subquery->jointree->quals, qual); |
| |
| /* |
| * We need not change the subquery's hasAggs or hasSublinks flags, |
| * since we can't be pushing down any aggregates that weren't there |
| * before, and we don't push down subselects at all. |
| */ |
| } |
| } |
| |
| /* |
| * Helper routine to recurse through setOperations tree |
| */ |
| static void |
| recurse_push_qual(Node *setOp, Query *topquery, |
| RangeTblEntry *rte, Index rti, Node *qual) |
| { |
| if (IsA(setOp, RangeTblRef)) |
| { |
| RangeTblRef *rtr = (RangeTblRef *) setOp; |
| RangeTblEntry *subrte = rt_fetch(rtr->rtindex, topquery->rtable); |
| Query *subquery = subrte->subquery; |
| |
| Assert(subquery != NULL); |
| subquery_push_qual(subquery, rte, rti, qual); |
| } |
| else if (IsA(setOp, SetOperationStmt)) |
| { |
| SetOperationStmt *op = (SetOperationStmt *) setOp; |
| |
| recurse_push_qual(op->larg, topquery, rte, rti, qual); |
| recurse_push_qual(op->rarg, topquery, rte, rti, qual); |
| } |
| else |
| { |
| elog(ERROR, "unrecognized node type: %d", |
| (int) nodeTag(setOp)); |
| } |
| } |
| |
| /* |
| * cdb_no_path_for_query |
| * |
| * Raise error when the set of allowable paths for a query is empty. |
| * Does not return. |
| */ |
| void |
| cdb_no_path_for_query(void) |
| { |
| StringInfoData buf; |
| |
| initStringInfo(&buf); |
| if (gp_guc_list_show(&buf, NULL, "%s=%s; ", PGC_S_DEFAULT, gp_guc_list_for_no_plan)) |
| ereport(ERROR, (errcode(ERRCODE_GP_FEATURE_NOT_CONFIGURED), |
| errmsg("Query requires a feature that has been disabled " |
| "by a configuration setting."), |
| errdetail("Could not devise a query plan for the given query."), |
| errhint("Current settings: %s", buf.data) |
| )); |
| else |
| elog(ERROR, "Could not devise a query plan for the given query."); |
| Insist(0); /* not reached */ |
| } /* cdb_no_path_for_query */ |
| |
| |
| |
| /***************************************************************************** |
| * DEBUG SUPPORT |
| *****************************************************************************/ |
| |
| #ifdef OPTIMIZER_DEBUG |
| |
| static void |
| print_relids(Relids relids) |
| { |
| Relids tmprelids; |
| int x; |
| bool first = true; |
| |
| tmprelids = bms_copy(relids); |
| while ((x = bms_first_member(tmprelids)) >= 0) |
| { |
| if (!first) |
| printf(" "); |
| printf("%d", x); |
| first = false; |
| } |
| bms_free(tmprelids); |
| } |
| |
| static void |
| print_restrictclauses(PlannerInfo *root, List *clauses) |
| { |
| ListCell *l; |
| |
| foreach(l, clauses) |
| { |
| RestrictInfo *c = lfirst(l); |
| |
| print_expr((Node *) c->clause, root->parse->rtable); |
| if (lnext(l)) |
| printf(", "); |
| } |
| } |
| |
| static void |
| print_path(PlannerInfo *root, Path *path, int indent) |
| { |
| const char *ptype; |
| bool join = false; |
| Path *subpath = NULL; |
| int i; |
| |
| switch (nodeTag(path)) |
| { |
| case T_Path: |
| ptype = "SeqScan"; |
| break; |
| case T_IndexPath: |
| ptype = "IdxScan"; |
| break; |
| case T_BitmapHeapPath: |
| ptype = "BitmapHeapScan"; |
| break; |
| case T_BitmapAppendOnlyPath: |
| if (((BitmapAppendOnlyPath *)path)->isAORow) |
| ptype = "BitmapAppendOnlyScan Row-oriented"; |
| else |
| ptype = "BitmapAppendOnlyScan Column-oriented"; |
| break; |
| case T_BitmapAndPath: |
| ptype = "BitmapAndPath"; |
| break; |
| case T_BitmapOrPath: |
| ptype = "BitmapOrPath"; |
| break; |
| case T_TidPath: |
| ptype = "TidScan"; |
| break; |
| case T_AppendPath: |
| ptype = "Append"; |
| break; |
| case T_ResultPath: |
| ptype = "Result"; |
| subpath = ((ResultPath *) path)->subpath; |
| break; |
| case T_MaterialPath: |
| ptype = "Material"; |
| subpath = ((MaterialPath *) path)->subpath; |
| break; |
| case T_UniquePath: |
| ptype = "Unique"; |
| subpath = ((UniquePath *) path)->subpath; |
| break; |
| case T_NestPath: |
| ptype = "NestLoop"; |
| join = true; |
| break; |
| case T_MergePath: |
| ptype = "MergeJoin"; |
| join = true; |
| break; |
| case T_HashPath: |
| ptype = "HashJoin"; |
| join = true; |
| break; |
| default: |
| ptype = "???Path"; |
| break; |
| } |
| |
| for (i = 0; i < indent; i++) |
| printf("\t"); |
| printf("%s", ptype); |
| |
| if (path->parent) |
| { |
| printf("("); |
| print_relids(path->parent->relids); |
| printf(") rows=%.0f", path->parent->rows); |
| } |
| printf(" cost=%.2f..%.2f\n", path->startup_cost, path->total_cost); |
| |
| if (path->pathkeys) |
| { |
| for (i = 0; i < indent; i++) |
| printf("\t"); |
| printf(" pathkeys: "); |
| print_pathkeys(path->pathkeys, root->parse->rtable); |
| } |
| |
| if (join) |
| { |
| JoinPath *jp = (JoinPath *) path; |
| |
| for (i = 0; i < indent; i++) |
| printf("\t"); |
| printf(" clauses: "); |
| print_restrictclauses(root, jp->joinrestrictinfo); |
| printf("\n"); |
| |
| if (IsA(path, MergePath)) |
| { |
| MergePath *mp = (MergePath *) path; |
| |
| if (mp->outersortkeys || mp->innersortkeys) |
| { |
| for (i = 0; i < indent; i++) |
| printf("\t"); |
| printf(" sortouter=%d sortinner=%d\n", |
| ((mp->outersortkeys) ? 1 : 0), |
| ((mp->innersortkeys) ? 1 : 0)); |
| } |
| } |
| |
| print_path(root, jp->outerjoinpath, indent + 1); |
| print_path(root, jp->innerjoinpath, indent + 1); |
| } |
| |
| if (subpath) |
| print_path(root, subpath, indent + 1); |
| } |
| |
| void |
| debug_print_rel(PlannerInfo *root, RelOptInfo *rel) |
| { |
| ListCell *l; |
| |
| printf("RELOPTINFO ("); |
| print_relids(rel->relids); |
| printf("): rows=%.0f width=%d\n", rel->rows, rel->width); |
| |
| if (rel->baserestrictinfo) |
| { |
| printf("\tbaserestrictinfo: "); |
| print_restrictclauses(root, rel->baserestrictinfo); |
| printf("\n"); |
| } |
| |
| if (rel->joininfo) |
| { |
| printf("\tjoininfo: "); |
| print_restrictclauses(root, rel->joininfo); |
| printf("\n"); |
| } |
| |
| printf("\tpath list:\n"); |
| foreach(l, rel->pathlist) |
| print_path(root, lfirst(l), 1); |
| printf("\n\tcheapest startup path:\n"); |
| print_path(root, rel->cheapest_startup_path, 1); |
| printf("\n\tcheapest total path:\n"); |
| print_path(root, rel->cheapest_total_path, 1); |
| printf("\n"); |
| fflush(stdout); |
| } |
| |
| #endif /* OPTIMIZER_DEBUG */ |