diff options
Diffstat (limited to 'src/backend/optimizer/util/pathnode.c')
| -rw-r--r-- | src/backend/optimizer/util/pathnode.c | 363 |
1 files changed, 363 insertions, 0 deletions
diff --git a/src/backend/optimizer/util/pathnode.c b/src/backend/optimizer/util/pathnode.c index 26567cb7f65..2d491eb0ba9 100644 --- a/src/backend/optimizer/util/pathnode.c +++ b/src/backend/optimizer/util/pathnode.c @@ -18,15 +18,20 @@ #include "miscadmin.h" #include "nodes/nodeFuncs.h" +#include "nodes/extensible.h" #include "optimizer/clauses.h" #include "optimizer/cost.h" #include "optimizer/pathnode.h" #include "optimizer/paths.h" #include "optimizer/planmain.h" +#include "optimizer/prep.h" #include "optimizer/restrictinfo.h" +#include "optimizer/tlist.h" #include "optimizer/var.h" #include "parser/parsetree.h" +#include "foreign/fdwapi.h" #include "utils/lsyscache.h" +#include "utils/memutils.h" #include "utils/selfuncs.h" @@ -46,6 +51,9 @@ typedef enum #define STD_FUZZ_FACTOR 1.01 static List *translate_sub_tlist(List *tlist, int relid); +static List *reparameterize_pathlist_by_child(PlannerInfo *root, + List *pathlist, + RelOptInfo *child_rel); /***************************************************************************** @@ -3429,3 +3437,358 @@ reparameterize_path(PlannerInfo *root, Path *path, } return NULL; } + +/* + * reparameterize_path_by_child + * Given a path parameterized by the parent of the given child relation, + * translate the path to be parameterized by the given child relation. + * + * The function creates a new path of the same type as the given path, but + * parameterized by the given child relation. Most fields from the original + * path can simply be flat-copied, but any expressions must be adjusted to + * refer to the correct varnos, and any paths must be recursively + * reparameterized. Other fields that refer to specific relids also need + * adjustment. + * + * The cost, number of rows, width and parallel path properties depend upon + * path->parent, which does not change during the translation. Hence those + * members are copied as they are. + * + * If the given path can not be reparameterized, the function returns NULL. + */ +Path * +reparameterize_path_by_child(PlannerInfo *root, Path *path, + RelOptInfo *child_rel) +{ + +#define FLAT_COPY_PATH(newnode, node, nodetype) \ + ( (newnode) = makeNode(nodetype), \ + memcpy((newnode), (node), sizeof(nodetype)) ) + +#define ADJUST_CHILD_ATTRS(node) \ + ((node) = \ + (List *) adjust_appendrel_attrs_multilevel(root, (Node *) (node), \ + child_rel->relids, \ + child_rel->top_parent_relids)) + +#define REPARAMETERIZE_CHILD_PATH(path) \ +do { \ + (path) = reparameterize_path_by_child(root, (path), child_rel); \ + if ((path) == NULL) \ + return NULL; \ +} while(0); + +#define REPARAMETERIZE_CHILD_PATH_LIST(pathlist) \ +do { \ + if ((pathlist) != NIL) \ + { \ + (pathlist) = reparameterize_pathlist_by_child(root, (pathlist), \ + child_rel); \ + if ((pathlist) == NIL) \ + return NULL; \ + } \ +} while(0); + + Path *new_path; + ParamPathInfo *new_ppi; + ParamPathInfo *old_ppi; + Relids required_outer; + + /* + * If the path is not parameterized by parent of the given relation, it + * doesn't need reparameterization. + */ + if (!path->param_info || + !bms_overlap(PATH_REQ_OUTER(path), child_rel->top_parent_relids)) + return path; + + /* Reparameterize a copy of given path. */ + switch (nodeTag(path)) + { + case T_Path: + FLAT_COPY_PATH(new_path, path, Path); + break; + + case T_IndexPath: + { + IndexPath *ipath; + + FLAT_COPY_PATH(ipath, path, IndexPath); + ADJUST_CHILD_ATTRS(ipath->indexclauses); + ADJUST_CHILD_ATTRS(ipath->indexquals); + new_path = (Path *) ipath; + } + break; + + case T_BitmapHeapPath: + { + BitmapHeapPath *bhpath; + + FLAT_COPY_PATH(bhpath, path, BitmapHeapPath); + REPARAMETERIZE_CHILD_PATH(bhpath->bitmapqual); + new_path = (Path *) bhpath; + } + break; + + case T_BitmapAndPath: + { + BitmapAndPath *bapath; + + FLAT_COPY_PATH(bapath, path, BitmapAndPath); + REPARAMETERIZE_CHILD_PATH_LIST(bapath->bitmapquals); + new_path = (Path *) bapath; + } + break; + + case T_BitmapOrPath: + { + BitmapOrPath *bopath; + + FLAT_COPY_PATH(bopath, path, BitmapOrPath); + REPARAMETERIZE_CHILD_PATH_LIST(bopath->bitmapquals); + new_path = (Path *) bopath; + } + break; + + case T_TidPath: + { + TidPath *tpath; + + /* + * TidPath contains tidquals, which do not contain any + * external parameters per create_tidscan_path(). So don't + * bother to translate those. + */ + FLAT_COPY_PATH(tpath, path, TidPath); + new_path = (Path *) tpath; + } + break; + + case T_ForeignPath: + { + ForeignPath *fpath; + ReparameterizeForeignPathByChild_function rfpc_func; + + FLAT_COPY_PATH(fpath, path, ForeignPath); + if (fpath->fdw_outerpath) + REPARAMETERIZE_CHILD_PATH(fpath->fdw_outerpath); + + /* Hand over to FDW if needed. */ + rfpc_func = + path->parent->fdwroutine->ReparameterizeForeignPathByChild; + if (rfpc_func) + fpath->fdw_private = rfpc_func(root, fpath->fdw_private, + child_rel); + new_path = (Path *) fpath; + } + break; + + case T_CustomPath: + { + CustomPath *cpath; + + FLAT_COPY_PATH(cpath, path, CustomPath); + REPARAMETERIZE_CHILD_PATH_LIST(cpath->custom_paths); + if (cpath->methods && + cpath->methods->ReparameterizeCustomPathByChild) + cpath->custom_private = + cpath->methods->ReparameterizeCustomPathByChild(root, + cpath->custom_private, + child_rel); + new_path = (Path *) cpath; + } + break; + + case T_NestPath: + { + JoinPath *jpath; + + FLAT_COPY_PATH(jpath, path, NestPath); + + REPARAMETERIZE_CHILD_PATH(jpath->outerjoinpath); + REPARAMETERIZE_CHILD_PATH(jpath->innerjoinpath); + ADJUST_CHILD_ATTRS(jpath->joinrestrictinfo); + new_path = (Path *) jpath; + } + break; + + case T_MergePath: + { + JoinPath *jpath; + MergePath *mpath; + + FLAT_COPY_PATH(mpath, path, MergePath); + + jpath = (JoinPath *) mpath; + REPARAMETERIZE_CHILD_PATH(jpath->outerjoinpath); + REPARAMETERIZE_CHILD_PATH(jpath->innerjoinpath); + ADJUST_CHILD_ATTRS(jpath->joinrestrictinfo); + ADJUST_CHILD_ATTRS(mpath->path_mergeclauses); + new_path = (Path *) mpath; + } + break; + + case T_HashPath: + { + JoinPath *jpath; + HashPath *hpath; + + FLAT_COPY_PATH(hpath, path, HashPath); + + jpath = (JoinPath *) hpath; + REPARAMETERIZE_CHILD_PATH(jpath->outerjoinpath); + REPARAMETERIZE_CHILD_PATH(jpath->innerjoinpath); + ADJUST_CHILD_ATTRS(jpath->joinrestrictinfo); + ADJUST_CHILD_ATTRS(hpath->path_hashclauses); + new_path = (Path *) hpath; + } + break; + + case T_AppendPath: + { + AppendPath *apath; + + FLAT_COPY_PATH(apath, path, AppendPath); + REPARAMETERIZE_CHILD_PATH_LIST(apath->subpaths); + new_path = (Path *) apath; + } + break; + + case T_MergeAppend: + { + MergeAppendPath *mapath; + + FLAT_COPY_PATH(mapath, path, MergeAppendPath); + REPARAMETERIZE_CHILD_PATH_LIST(mapath->subpaths); + new_path = (Path *) mapath; + } + break; + + case T_MaterialPath: + { + MaterialPath *mpath; + + FLAT_COPY_PATH(mpath, path, MaterialPath); + REPARAMETERIZE_CHILD_PATH(mpath->subpath); + new_path = (Path *) mpath; + } + break; + + case T_UniquePath: + { + UniquePath *upath; + + FLAT_COPY_PATH(upath, path, UniquePath); + REPARAMETERIZE_CHILD_PATH(upath->subpath); + ADJUST_CHILD_ATTRS(upath->uniq_exprs); + new_path = (Path *) upath; + } + break; + + case T_GatherPath: + { + GatherPath *gpath; + + FLAT_COPY_PATH(gpath, path, GatherPath); + REPARAMETERIZE_CHILD_PATH(gpath->subpath); + new_path = (Path *) gpath; + } + break; + + case T_GatherMergePath: + { + GatherMergePath *gmpath; + + FLAT_COPY_PATH(gmpath, path, GatherMergePath); + REPARAMETERIZE_CHILD_PATH(gmpath->subpath); + new_path = (Path *) gmpath; + } + break; + + default: + + /* We don't know how to reparameterize this path. */ + return NULL; + } + + /* + * Adjust the parameterization information, which refers to the topmost + * parent. The topmost parent can be multiple levels away from the given + * child, hence use multi-level expression adjustment routines. + */ + old_ppi = new_path->param_info; + required_outer = + adjust_child_relids_multilevel(root, old_ppi->ppi_req_outer, + child_rel->relids, + child_rel->top_parent_relids); + + /* If we already have a PPI for this parameterization, just return it */ + new_ppi = find_param_path_info(new_path->parent, required_outer); + + /* + * If not, build a new one and link it to the list of PPIs. For the same + * reason as explained in mark_dummy_rel(), allocate new PPI in the same + * context the given RelOptInfo is in. + */ + if (new_ppi == NULL) + { + MemoryContext oldcontext; + RelOptInfo *rel = path->parent; + + oldcontext = MemoryContextSwitchTo(GetMemoryChunkContext(rel)); + + new_ppi = makeNode(ParamPathInfo); + new_ppi->ppi_req_outer = bms_copy(required_outer); + new_ppi->ppi_rows = old_ppi->ppi_rows; + new_ppi->ppi_clauses = old_ppi->ppi_clauses; + ADJUST_CHILD_ATTRS(new_ppi->ppi_clauses); + rel->ppilist = lappend(rel->ppilist, new_ppi); + + MemoryContextSwitchTo(oldcontext); + } + bms_free(required_outer); + + new_path->param_info = new_ppi; + + /* + * Adjust the path target if the parent of the outer relation is + * referenced in the targetlist. This can happen when only the parent of + * outer relation is laterally referenced in this relation. + */ + if (bms_overlap(path->parent->lateral_relids, + child_rel->top_parent_relids)) + { + new_path->pathtarget = copy_pathtarget(new_path->pathtarget); + ADJUST_CHILD_ATTRS(new_path->pathtarget->exprs); + } + + return new_path; +} + +/* + * reparameterize_pathlist_by_child + * Helper function to reparameterize a list of paths by given child rel. + */ +static List * +reparameterize_pathlist_by_child(PlannerInfo *root, + List *pathlist, + RelOptInfo *child_rel) +{ + ListCell *lc; + List *result = NIL; + + foreach(lc, pathlist) + { + Path *path = reparameterize_path_by_child(root, lfirst(lc), + child_rel); + if (path == NULL) + { + list_free(result); + return NIL; + } + + result = lappend(result, path); + } + + return result; +} |