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Diffstat (limited to 'src/backend/optimizer/util/inherit.c')
| -rw-r--r-- | src/backend/optimizer/util/inherit.c | 949 |
1 files changed, 949 insertions, 0 deletions
diff --git a/src/backend/optimizer/util/inherit.c b/src/backend/optimizer/util/inherit.c new file mode 100644 index 0000000..3c11f5d --- /dev/null +++ b/src/backend/optimizer/util/inherit.c @@ -0,0 +1,949 @@ +/*------------------------------------------------------------------------- + * + * inherit.c + * Routines to process child relations in inheritance trees + * + * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * + * IDENTIFICATION + * src/backend/optimizer/util/inherit.c + * + *------------------------------------------------------------------------- + */ +#include "postgres.h" + +#include "access/sysattr.h" +#include "access/table.h" +#include "catalog/partition.h" +#include "catalog/pg_inherits.h" +#include "catalog/pg_type.h" +#include "miscadmin.h" +#include "nodes/makefuncs.h" +#include "optimizer/appendinfo.h" +#include "optimizer/inherit.h" +#include "optimizer/optimizer.h" +#include "optimizer/pathnode.h" +#include "optimizer/plancat.h" +#include "optimizer/planmain.h" +#include "optimizer/planner.h" +#include "optimizer/prep.h" +#include "optimizer/restrictinfo.h" +#include "parser/parsetree.h" +#include "partitioning/partdesc.h" +#include "partitioning/partprune.h" +#include "utils/rel.h" + + +static void expand_partitioned_rtentry(PlannerInfo *root, RelOptInfo *relinfo, + RangeTblEntry *parentrte, + Index parentRTindex, Relation parentrel, + PlanRowMark *top_parentrc, LOCKMODE lockmode); +static void expand_single_inheritance_child(PlannerInfo *root, + RangeTblEntry *parentrte, + Index parentRTindex, Relation parentrel, + PlanRowMark *top_parentrc, Relation childrel, + RangeTblEntry **childrte_p, + Index *childRTindex_p); +static Bitmapset *translate_col_privs(const Bitmapset *parent_privs, + List *translated_vars); +static Bitmapset *translate_col_privs_multilevel(PlannerInfo *root, + RelOptInfo *rel, + RelOptInfo *parent_rel, + Bitmapset *parent_cols); +static void expand_appendrel_subquery(PlannerInfo *root, RelOptInfo *rel, + RangeTblEntry *rte, Index rti); + + +/* + * expand_inherited_rtentry + * Expand a rangetable entry that has the "inh" bit set. + * + * "inh" is only allowed in two cases: RELATION and SUBQUERY RTEs. + * + * "inh" on a plain RELATION RTE means that it is a partitioned table or the + * parent of a traditional-inheritance set. In this case we must add entries + * for all the interesting child tables to the query's rangetable, and build + * additional planner data structures for them, including RelOptInfos, + * AppendRelInfos, and possibly PlanRowMarks. + * + * Note that the original RTE is considered to represent the whole inheritance + * set. In the case of traditional inheritance, the first of the generated + * RTEs is an RTE for the same table, but with inh = false, to represent the + * parent table in its role as a simple member of the inheritance set. For + * partitioning, we don't need a second RTE because the partitioned table + * itself has no data and need not be scanned. + * + * "inh" on a SUBQUERY RTE means that it's the parent of a UNION ALL group, + * which is treated as an appendrel similarly to inheritance cases; however, + * we already made RTEs and AppendRelInfos for the subqueries. We only need + * to build RelOptInfos for them, which is done by expand_appendrel_subquery. + */ +void +expand_inherited_rtentry(PlannerInfo *root, RelOptInfo *rel, + RangeTblEntry *rte, Index rti) +{ + Oid parentOID; + Relation oldrelation; + LOCKMODE lockmode; + PlanRowMark *oldrc; + bool old_isParent = false; + int old_allMarkTypes = 0; + + Assert(rte->inh); /* else caller error */ + + if (rte->rtekind == RTE_SUBQUERY) + { + expand_appendrel_subquery(root, rel, rte, rti); + return; + } + + Assert(rte->rtekind == RTE_RELATION); + + parentOID = rte->relid; + + /* + * We used to check has_subclass() here, but there's no longer any need + * to, because subquery_planner already did. + */ + + /* + * The rewriter should already have obtained an appropriate lock on each + * relation named in the query, so we can open the parent relation without + * locking it. However, for each child relation we add to the query, we + * must obtain an appropriate lock, because this will be the first use of + * those relations in the parse/rewrite/plan pipeline. Child rels should + * use the same lockmode as their parent. + */ + oldrelation = table_open(parentOID, NoLock); + lockmode = rte->rellockmode; + + /* + * If parent relation is selected FOR UPDATE/SHARE, we need to mark its + * PlanRowMark as isParent = true, and generate a new PlanRowMark for each + * child. + */ + oldrc = get_plan_rowmark(root->rowMarks, rti); + if (oldrc) + { + old_isParent = oldrc->isParent; + oldrc->isParent = true; + /* Save initial value of allMarkTypes before children add to it */ + old_allMarkTypes = oldrc->allMarkTypes; + } + + /* Scan the inheritance set and expand it */ + if (oldrelation->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) + { + /* + * Partitioned table, so set up for partitioning. + */ + Assert(rte->relkind == RELKIND_PARTITIONED_TABLE); + + /* + * Recursively expand and lock the partitions. While at it, also + * extract the partition key columns of all the partitioned tables. + */ + expand_partitioned_rtentry(root, rel, rte, rti, + oldrelation, oldrc, lockmode); + } + else + { + /* + * Ordinary table, so process traditional-inheritance children. (Note + * that partitioned tables are not allowed to have inheritance + * children, so it's not possible for both cases to apply.) + */ + List *inhOIDs; + ListCell *l; + + /* Scan for all members of inheritance set, acquire needed locks */ + inhOIDs = find_all_inheritors(parentOID, lockmode, NULL); + + /* + * We used to special-case the situation where the table no longer has + * any children, by clearing rte->inh and exiting. That no longer + * works, because this function doesn't get run until after decisions + * have been made that depend on rte->inh. We have to treat such + * situations as normal inheritance. The table itself should always + * have been found, though. + */ + Assert(inhOIDs != NIL); + Assert(linitial_oid(inhOIDs) == parentOID); + + /* Expand simple_rel_array and friends to hold child objects. */ + expand_planner_arrays(root, list_length(inhOIDs)); + + /* + * Expand inheritance children in the order the OIDs were returned by + * find_all_inheritors. + */ + foreach(l, inhOIDs) + { + Oid childOID = lfirst_oid(l); + Relation newrelation; + RangeTblEntry *childrte; + Index childRTindex; + + /* Open rel if needed; we already have required locks */ + if (childOID != parentOID) + newrelation = table_open(childOID, NoLock); + else + newrelation = oldrelation; + + /* + * It is possible that the parent table has children that are temp + * tables of other backends. We cannot safely access such tables + * (because of buffering issues), and the best thing to do seems + * to be to silently ignore them. + */ + if (childOID != parentOID && RELATION_IS_OTHER_TEMP(newrelation)) + { + table_close(newrelation, lockmode); + continue; + } + + /* Create RTE and AppendRelInfo, plus PlanRowMark if needed. */ + expand_single_inheritance_child(root, rte, rti, oldrelation, + oldrc, newrelation, + &childrte, &childRTindex); + + /* Create the otherrel RelOptInfo too. */ + (void) build_simple_rel(root, childRTindex, rel); + + /* Close child relations, but keep locks */ + if (childOID != parentOID) + table_close(newrelation, NoLock); + } + } + + /* + * Some children might require different mark types, which would've been + * reported into oldrc. If so, add relevant entries to the top-level + * targetlist and update parent rel's reltarget. This should match what + * preprocess_targetlist() would have added if the mark types had been + * requested originally. + * + * (Someday it might be useful to fold these resjunk columns into the + * row-identity-column management used for UPDATE/DELETE. Today is not + * that day, however.) + */ + if (oldrc) + { + int new_allMarkTypes = oldrc->allMarkTypes; + Var *var; + TargetEntry *tle; + char resname[32]; + List *newvars = NIL; + + /* Add TID junk Var if needed, unless we had it already */ + if (new_allMarkTypes & ~(1 << ROW_MARK_COPY) && + !(old_allMarkTypes & ~(1 << ROW_MARK_COPY))) + { + /* Need to fetch TID */ + var = makeVar(oldrc->rti, + SelfItemPointerAttributeNumber, + TIDOID, + -1, + InvalidOid, + 0); + snprintf(resname, sizeof(resname), "ctid%u", oldrc->rowmarkId); + tle = makeTargetEntry((Expr *) var, + list_length(root->processed_tlist) + 1, + pstrdup(resname), + true); + root->processed_tlist = lappend(root->processed_tlist, tle); + newvars = lappend(newvars, var); + } + + /* Add whole-row junk Var if needed, unless we had it already */ + if ((new_allMarkTypes & (1 << ROW_MARK_COPY)) && + !(old_allMarkTypes & (1 << ROW_MARK_COPY))) + { + var = makeWholeRowVar(planner_rt_fetch(oldrc->rti, root), + oldrc->rti, + 0, + false); + snprintf(resname, sizeof(resname), "wholerow%u", oldrc->rowmarkId); + tle = makeTargetEntry((Expr *) var, + list_length(root->processed_tlist) + 1, + pstrdup(resname), + true); + root->processed_tlist = lappend(root->processed_tlist, tle); + newvars = lappend(newvars, var); + } + + /* Add tableoid junk Var, unless we had it already */ + if (!old_isParent) + { + var = makeVar(oldrc->rti, + TableOidAttributeNumber, + OIDOID, + -1, + InvalidOid, + 0); + snprintf(resname, sizeof(resname), "tableoid%u", oldrc->rowmarkId); + tle = makeTargetEntry((Expr *) var, + list_length(root->processed_tlist) + 1, + pstrdup(resname), + true); + root->processed_tlist = lappend(root->processed_tlist, tle); + newvars = lappend(newvars, var); + } + + /* + * Add the newly added Vars to parent's reltarget. We needn't worry + * about the children's reltargets, they'll be made later. + */ + add_vars_to_targetlist(root, newvars, bms_make_singleton(0), false); + } + + table_close(oldrelation, NoLock); +} + +/* + * expand_partitioned_rtentry + * Recursively expand an RTE for a partitioned table. + */ +static void +expand_partitioned_rtentry(PlannerInfo *root, RelOptInfo *relinfo, + RangeTblEntry *parentrte, + Index parentRTindex, Relation parentrel, + PlanRowMark *top_parentrc, LOCKMODE lockmode) +{ + PartitionDesc partdesc; + Bitmapset *live_parts; + int num_live_parts; + int i; + + check_stack_depth(); + + Assert(parentrte->inh); + + partdesc = PartitionDirectoryLookup(root->glob->partition_directory, + parentrel); + + /* A partitioned table should always have a partition descriptor. */ + Assert(partdesc); + + /* + * Note down whether any partition key cols are being updated. Though it's + * the root partitioned table's updatedCols we are interested in, we + * instead use parentrte to get the updatedCols. This is convenient + * because parentrte already has the root partrel's updatedCols translated + * to match the attribute ordering of parentrel. + */ + if (!root->partColsUpdated) + root->partColsUpdated = + has_partition_attrs(parentrel, parentrte->updatedCols, NULL); + + /* Nothing further to do here if there are no partitions. */ + if (partdesc->nparts == 0) + return; + + /* + * Perform partition pruning using restriction clauses assigned to parent + * relation. live_parts will contain PartitionDesc indexes of partitions + * that survive pruning. Below, we will initialize child objects for the + * surviving partitions. + */ + relinfo->live_parts = live_parts = prune_append_rel_partitions(relinfo); + + /* Expand simple_rel_array and friends to hold child objects. */ + num_live_parts = bms_num_members(live_parts); + if (num_live_parts > 0) + expand_planner_arrays(root, num_live_parts); + + /* + * We also store partition RelOptInfo pointers in the parent relation. + * Since we're palloc0'ing, slots corresponding to pruned partitions will + * contain NULL. + */ + Assert(relinfo->part_rels == NULL); + relinfo->part_rels = (RelOptInfo **) + palloc0(relinfo->nparts * sizeof(RelOptInfo *)); + + /* + * Create a child RTE for each live partition. Note that unlike + * traditional inheritance, we don't need a child RTE for the partitioned + * table itself, because it's not going to be scanned. + */ + i = -1; + while ((i = bms_next_member(live_parts, i)) >= 0) + { + Oid childOID = partdesc->oids[i]; + Relation childrel; + RangeTblEntry *childrte; + Index childRTindex; + RelOptInfo *childrelinfo; + + /* Open rel, acquiring required locks */ + childrel = table_open(childOID, lockmode); + + /* + * Temporary partitions belonging to other sessions should have been + * disallowed at definition, but for paranoia's sake, let's double + * check. + */ + if (RELATION_IS_OTHER_TEMP(childrel)) + elog(ERROR, "temporary relation from another session found as partition"); + + /* Create RTE and AppendRelInfo, plus PlanRowMark if needed. */ + expand_single_inheritance_child(root, parentrte, parentRTindex, + parentrel, top_parentrc, childrel, + &childrte, &childRTindex); + + /* Create the otherrel RelOptInfo too. */ + childrelinfo = build_simple_rel(root, childRTindex, relinfo); + relinfo->part_rels[i] = childrelinfo; + relinfo->all_partrels = bms_add_members(relinfo->all_partrels, + childrelinfo->relids); + + /* If this child is itself partitioned, recurse */ + if (childrel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE) + expand_partitioned_rtentry(root, childrelinfo, + childrte, childRTindex, + childrel, top_parentrc, lockmode); + + /* Close child relation, but keep locks */ + table_close(childrel, NoLock); + } +} + +/* + * expand_single_inheritance_child + * Build a RangeTblEntry and an AppendRelInfo, plus maybe a PlanRowMark. + * + * We now expand the partition hierarchy level by level, creating a + * corresponding hierarchy of AppendRelInfos and RelOptInfos, where each + * partitioned descendant acts as a parent of its immediate partitions. + * (This is a difference from what older versions of PostgreSQL did and what + * is still done in the case of table inheritance for unpartitioned tables, + * where the hierarchy is flattened during RTE expansion.) + * + * PlanRowMarks still carry the top-parent's RTI, and the top-parent's + * allMarkTypes field still accumulates values from all descendents. + * + * "parentrte" and "parentRTindex" are immediate parent's RTE and + * RTI. "top_parentrc" is top parent's PlanRowMark. + * + * The child RangeTblEntry and its RTI are returned in "childrte_p" and + * "childRTindex_p" resp. + */ +static void +expand_single_inheritance_child(PlannerInfo *root, RangeTblEntry *parentrte, + Index parentRTindex, Relation parentrel, + PlanRowMark *top_parentrc, Relation childrel, + RangeTblEntry **childrte_p, + Index *childRTindex_p) +{ + Query *parse = root->parse; + Oid parentOID = RelationGetRelid(parentrel); + Oid childOID = RelationGetRelid(childrel); + RangeTblEntry *childrte; + Index childRTindex; + AppendRelInfo *appinfo; + TupleDesc child_tupdesc; + List *parent_colnames; + List *child_colnames; + + /* + * Build an RTE for the child, and attach to query's rangetable list. We + * copy most scalar fields of the parent's RTE, but replace relation OID, + * relkind, and inh for the child. Also, set requiredPerms to zero since + * all required permissions checks are done on the original RTE. Likewise, + * set the child's securityQuals to empty, because we only want to apply + * the parent's RLS conditions regardless of what RLS properties + * individual children may have. (This is an intentional choice to make + * inherited RLS work like regular permissions checks.) The parent + * securityQuals will be propagated to children along with other base + * restriction clauses, so we don't need to do it here. Other + * infrastructure of the parent RTE has to be translated to match the + * child table's column ordering, which we do below, so a "flat" copy is + * sufficient to start with. + */ + childrte = makeNode(RangeTblEntry); + memcpy(childrte, parentrte, sizeof(RangeTblEntry)); + Assert(parentrte->rtekind == RTE_RELATION); /* else this is dubious */ + childrte->relid = childOID; + childrte->relkind = childrel->rd_rel->relkind; + /* A partitioned child will need to be expanded further. */ + if (childrte->relkind == RELKIND_PARTITIONED_TABLE) + { + Assert(childOID != parentOID); + childrte->inh = true; + } + else + childrte->inh = false; + childrte->requiredPerms = 0; + childrte->securityQuals = NIL; + + /* Link not-yet-fully-filled child RTE into data structures */ + parse->rtable = lappend(parse->rtable, childrte); + childRTindex = list_length(parse->rtable); + *childrte_p = childrte; + *childRTindex_p = childRTindex; + + /* + * Build an AppendRelInfo struct for each parent/child pair. + */ + appinfo = make_append_rel_info(parentrel, childrel, + parentRTindex, childRTindex); + root->append_rel_list = lappend(root->append_rel_list, appinfo); + + /* tablesample is probably null, but copy it */ + childrte->tablesample = copyObject(parentrte->tablesample); + + /* + * Construct an alias clause for the child, which we can also use as eref. + * This is important so that EXPLAIN will print the right column aliases + * for child-table columns. (Since ruleutils.c doesn't have any easy way + * to reassociate parent and child columns, we must get the child column + * aliases right to start with. Note that setting childrte->alias forces + * ruleutils.c to use these column names, which it otherwise would not.) + */ + child_tupdesc = RelationGetDescr(childrel); + parent_colnames = parentrte->eref->colnames; + child_colnames = NIL; + for (int cattno = 0; cattno < child_tupdesc->natts; cattno++) + { + Form_pg_attribute att = TupleDescAttr(child_tupdesc, cattno); + const char *attname; + + if (att->attisdropped) + { + /* Always insert an empty string for a dropped column */ + attname = ""; + } + else if (appinfo->parent_colnos[cattno] > 0 && + appinfo->parent_colnos[cattno] <= list_length(parent_colnames)) + { + /* Duplicate the query-assigned name for the parent column */ + attname = strVal(list_nth(parent_colnames, + appinfo->parent_colnos[cattno] - 1)); + } + else + { + /* New column, just use its real name */ + attname = NameStr(att->attname); + } + child_colnames = lappend(child_colnames, makeString(pstrdup(attname))); + } + + /* + * We just duplicate the parent's table alias name for each child. If the + * plan gets printed, ruleutils.c has to sort out unique table aliases to + * use, which it can handle. + */ + childrte->alias = childrte->eref = makeAlias(parentrte->eref->aliasname, + child_colnames); + + /* + * Translate the column permissions bitmaps to the child's attnums (we + * have to build the translated_vars list before we can do this). But if + * this is the parent table, we can just duplicate the parent's bitmaps. + * + * Note: we need to do this even though the executor won't run any + * permissions checks on the child RTE. The insertedCols/updatedCols + * bitmaps may be examined for trigger-firing purposes. + */ + if (childOID != parentOID) + { + childrte->selectedCols = translate_col_privs(parentrte->selectedCols, + appinfo->translated_vars); + childrte->insertedCols = translate_col_privs(parentrte->insertedCols, + appinfo->translated_vars); + childrte->updatedCols = translate_col_privs(parentrte->updatedCols, + appinfo->translated_vars); + } + else + { + childrte->selectedCols = bms_copy(parentrte->selectedCols); + childrte->insertedCols = bms_copy(parentrte->insertedCols); + childrte->updatedCols = bms_copy(parentrte->updatedCols); + } + + /* + * Store the RTE and appinfo in the respective PlannerInfo arrays, which + * the caller must already have allocated space for. + */ + Assert(childRTindex < root->simple_rel_array_size); + Assert(root->simple_rte_array[childRTindex] == NULL); + root->simple_rte_array[childRTindex] = childrte; + Assert(root->append_rel_array[childRTindex] == NULL); + root->append_rel_array[childRTindex] = appinfo; + + /* + * Build a PlanRowMark if parent is marked FOR UPDATE/SHARE. + */ + if (top_parentrc) + { + PlanRowMark *childrc = makeNode(PlanRowMark); + + childrc->rti = childRTindex; + childrc->prti = top_parentrc->rti; + childrc->rowmarkId = top_parentrc->rowmarkId; + /* Reselect rowmark type, because relkind might not match parent */ + childrc->markType = select_rowmark_type(childrte, + top_parentrc->strength); + childrc->allMarkTypes = (1 << childrc->markType); + childrc->strength = top_parentrc->strength; + childrc->waitPolicy = top_parentrc->waitPolicy; + + /* + * We mark RowMarks for partitioned child tables as parent RowMarks so + * that the executor ignores them (except their existence means that + * the child tables will be locked using the appropriate mode). + */ + childrc->isParent = (childrte->relkind == RELKIND_PARTITIONED_TABLE); + + /* Include child's rowmark type in top parent's allMarkTypes */ + top_parentrc->allMarkTypes |= childrc->allMarkTypes; + + root->rowMarks = lappend(root->rowMarks, childrc); + } + + /* + * If we are creating a child of the query target relation (only possible + * in UPDATE/DELETE/MERGE), add it to all_result_relids, as well as + * leaf_result_relids if appropriate, and make sure that we generate + * required row-identity data. + */ + if (bms_is_member(parentRTindex, root->all_result_relids)) + { + /* OK, record the child as a result rel too. */ + root->all_result_relids = bms_add_member(root->all_result_relids, + childRTindex); + + /* Non-leaf partitions don't need any row identity info. */ + if (childrte->relkind != RELKIND_PARTITIONED_TABLE) + { + Var *rrvar; + + root->leaf_result_relids = bms_add_member(root->leaf_result_relids, + childRTindex); + + /* + * If we have any child target relations, assume they all need to + * generate a junk "tableoid" column. (If only one child survives + * pruning, we wouldn't really need this, but it's not worth + * thrashing about to avoid it.) + */ + rrvar = makeVar(childRTindex, + TableOidAttributeNumber, + OIDOID, + -1, + InvalidOid, + 0); + add_row_identity_var(root, rrvar, childRTindex, "tableoid"); + + /* Register any row-identity columns needed by this child. */ + add_row_identity_columns(root, childRTindex, + childrte, childrel); + } + } +} + +/* + * get_rel_all_updated_cols + * Returns the set of columns of a given "simple" relation that are + * updated by this query. + */ +Bitmapset * +get_rel_all_updated_cols(PlannerInfo *root, RelOptInfo *rel) +{ + Index relid; + RangeTblEntry *rte; + Bitmapset *updatedCols, + *extraUpdatedCols; + + Assert(root->parse->commandType == CMD_UPDATE); + Assert(IS_SIMPLE_REL(rel)); + + /* + * We obtain updatedCols for the query's result relation. Then, if + * necessary, we map it to the column numbers of the relation for which + * they were requested. + */ + relid = root->parse->resultRelation; + rte = planner_rt_fetch(relid, root); + + updatedCols = rte->updatedCols; + + if (rel->relid != relid) + { + RelOptInfo *top_parent_rel = find_base_rel(root, relid); + + Assert(IS_OTHER_REL(rel)); + + updatedCols = translate_col_privs_multilevel(root, rel, top_parent_rel, + updatedCols); + } + + /* + * Now we must check to see if there are any generated columns that depend + * on the updatedCols, and add them to the result. + */ + extraUpdatedCols = get_dependent_generated_columns(root, rel->relid, + updatedCols); + + return bms_union(updatedCols, extraUpdatedCols); +} + +/* + * translate_col_privs + * Translate a bitmapset representing per-column privileges from the + * parent rel's attribute numbering to the child's. + * + * The only surprise here is that we don't translate a parent whole-row + * reference into a child whole-row reference. That would mean requiring + * permissions on all child columns, which is overly strict, since the + * query is really only going to reference the inherited columns. Instead + * we set the per-column bits for all inherited columns. + */ +static Bitmapset * +translate_col_privs(const Bitmapset *parent_privs, + List *translated_vars) +{ + Bitmapset *child_privs = NULL; + bool whole_row; + int attno; + ListCell *lc; + + /* System attributes have the same numbers in all tables */ + for (attno = FirstLowInvalidHeapAttributeNumber + 1; attno < 0; attno++) + { + if (bms_is_member(attno - FirstLowInvalidHeapAttributeNumber, + parent_privs)) + child_privs = bms_add_member(child_privs, + attno - FirstLowInvalidHeapAttributeNumber); + } + + /* Check if parent has whole-row reference */ + whole_row = bms_is_member(InvalidAttrNumber - FirstLowInvalidHeapAttributeNumber, + parent_privs); + + /* And now translate the regular user attributes, using the vars list */ + attno = InvalidAttrNumber; + foreach(lc, translated_vars) + { + Var *var = lfirst_node(Var, lc); + + attno++; + if (var == NULL) /* ignore dropped columns */ + continue; + if (whole_row || + bms_is_member(attno - FirstLowInvalidHeapAttributeNumber, + parent_privs)) + child_privs = bms_add_member(child_privs, + var->varattno - FirstLowInvalidHeapAttributeNumber); + } + + return child_privs; +} + +/* + * translate_col_privs_multilevel + * Recursively translates the column numbers contained in 'parent_cols' + * to the column numbers of a descendant relation given by 'rel' + * + * Note that because this is based on translate_col_privs, it will expand + * a whole-row reference into all inherited columns. This is not an issue + * for current usages, but beware. + */ +static Bitmapset * +translate_col_privs_multilevel(PlannerInfo *root, RelOptInfo *rel, + RelOptInfo *parent_rel, + Bitmapset *parent_cols) +{ + AppendRelInfo *appinfo; + + /* Fast path for easy case. */ + if (parent_cols == NULL) + return NULL; + + Assert(root->append_rel_array != NULL); + appinfo = root->append_rel_array[rel->relid]; + Assert(appinfo != NULL); + + /* Recurse if immediate parent is not the top parent. */ + if (appinfo->parent_relid != parent_rel->relid) + { + RelOptInfo *next_parent = find_base_rel(root, appinfo->parent_relid); + + parent_cols = translate_col_privs_multilevel(root, next_parent, + parent_rel, + parent_cols); + } + + /* Now translate for this child. */ + return translate_col_privs(parent_cols, appinfo->translated_vars); +} + +/* + * expand_appendrel_subquery + * Add "other rel" RelOptInfos for the children of an appendrel baserel + * + * "rel" is a subquery relation that has the rte->inh flag set, meaning it + * is a UNION ALL subquery that's been flattened into an appendrel, with + * child subqueries listed in root->append_rel_list. We need to build + * a RelOptInfo for each child relation so that we can plan scans on them. + */ +static void +expand_appendrel_subquery(PlannerInfo *root, RelOptInfo *rel, + RangeTblEntry *rte, Index rti) +{ + ListCell *l; + + foreach(l, root->append_rel_list) + { + AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l); + Index childRTindex = appinfo->child_relid; + RangeTblEntry *childrte; + RelOptInfo *childrel; + + /* append_rel_list contains all append rels; ignore others */ + if (appinfo->parent_relid != rti) + continue; + + /* find the child RTE, which should already exist */ + Assert(childRTindex < root->simple_rel_array_size); + childrte = root->simple_rte_array[childRTindex]; + Assert(childrte != NULL); + + /* Build the child RelOptInfo. */ + childrel = build_simple_rel(root, childRTindex, rel); + + /* Child may itself be an inherited rel, either table or subquery. */ + if (childrte->inh) + expand_inherited_rtentry(root, childrel, childrte, childRTindex); + } +} + + +/* + * apply_child_basequals + * Populate childrel's base restriction quals from parent rel's quals, + * translating them using appinfo. + * + * If any of the resulting clauses evaluate to constant false or NULL, we + * return false and don't apply any quals. Caller should mark the relation as + * a dummy rel in this case, since it doesn't need to be scanned. + */ +bool +apply_child_basequals(PlannerInfo *root, RelOptInfo *parentrel, + RelOptInfo *childrel, RangeTblEntry *childRTE, + AppendRelInfo *appinfo) +{ + List *childquals; + Index cq_min_security; + ListCell *lc; + + /* + * The child rel's targetlist might contain non-Var expressions, which + * means that substitution into the quals could produce opportunities for + * const-simplification, and perhaps even pseudoconstant quals. Therefore, + * transform each RestrictInfo separately to see if it reduces to a + * constant or pseudoconstant. (We must process them separately to keep + * track of the security level of each qual.) + */ + childquals = NIL; + cq_min_security = UINT_MAX; + foreach(lc, parentrel->baserestrictinfo) + { + RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc); + Node *childqual; + ListCell *lc2; + + Assert(IsA(rinfo, RestrictInfo)); + childqual = adjust_appendrel_attrs(root, + (Node *) rinfo->clause, + 1, &appinfo); + childqual = eval_const_expressions(root, childqual); + /* check for flat-out constant */ + if (childqual && IsA(childqual, Const)) + { + if (((Const *) childqual)->constisnull || + !DatumGetBool(((Const *) childqual)->constvalue)) + { + /* Restriction reduces to constant FALSE or NULL */ + return false; + } + /* Restriction reduces to constant TRUE, so drop it */ + continue; + } + /* might have gotten an AND clause, if so flatten it */ + foreach(lc2, make_ands_implicit((Expr *) childqual)) + { + Node *onecq = (Node *) lfirst(lc2); + bool pseudoconstant; + + /* check for pseudoconstant (no Vars or volatile functions) */ + pseudoconstant = + !contain_vars_of_level(onecq, 0) && + !contain_volatile_functions(onecq); + if (pseudoconstant) + { + /* tell createplan.c to check for gating quals */ + root->hasPseudoConstantQuals = true; + } + /* reconstitute RestrictInfo with appropriate properties */ + childquals = lappend(childquals, + make_restrictinfo(root, + (Expr *) onecq, + rinfo->is_pushed_down, + rinfo->outerjoin_delayed, + pseudoconstant, + rinfo->security_level, + NULL, NULL, NULL)); + /* track minimum security level among child quals */ + cq_min_security = Min(cq_min_security, rinfo->security_level); + } + } + + /* + * In addition to the quals inherited from the parent, we might have + * securityQuals associated with this particular child node. (Currently + * this can only happen in appendrels originating from UNION ALL; + * inheritance child tables don't have their own securityQuals, see + * expand_single_inheritance_child().) Pull any such securityQuals up + * into the baserestrictinfo for the child. This is similar to + * process_security_barrier_quals() for the parent rel, except that we + * can't make any general deductions from such quals, since they don't + * hold for the whole appendrel. + */ + if (childRTE->securityQuals) + { + Index security_level = 0; + + foreach(lc, childRTE->securityQuals) + { + List *qualset = (List *) lfirst(lc); + ListCell *lc2; + + foreach(lc2, qualset) + { + Expr *qual = (Expr *) lfirst(lc2); + + /* not likely that we'd see constants here, so no check */ + childquals = lappend(childquals, + make_restrictinfo(root, qual, + true, false, false, + security_level, + NULL, NULL, NULL)); + cq_min_security = Min(cq_min_security, security_level); + } + security_level++; + } + Assert(security_level <= root->qual_security_level); + } + + /* + * OK, we've got all the baserestrictinfo quals for this child. + */ + childrel->baserestrictinfo = childquals; + childrel->baserestrict_min_security = cq_min_security; + + return true; +} |