/* ---------------- * BuildIndexInfo * Construct an IndexInfo record for an open index * * IndexInfo stores the information about the index that's needed by * FormIndexDatum, which is used for both index_build() and later insertion * of individual index tuples. Normally we build an IndexInfo for an index * just once per command, and then use it for (potentially) many tuples. * ---------------- */ IndexInfo * BuildIndexInfo(Relation index) { IndexInfo *ii = makeNode(IndexInfo); Form_pg_index indexStruct = index->rd_index; int i; int numKeys; /* check the number of keys, and copy attr numbers into the IndexInfo */ numKeys = indexStruct->indnatts; if (numKeys < 1 || numKeys > INDEX_MAX_KEYS) elog(ERROR, "invalid indnatts %d for index %u", numKeys, RelationGetRelid(index)); ii->ii_NumIndexAttrs = numKeys; for (i = 0; i < numKeys; i++) ii->ii_KeyAttrNumbers[i] = indexStruct->indkey[i]; /* fetch any expressions needed for expressional indexes */ ii->ii_Expressions = RelationGetIndexExpressions(index); ii->ii_ExpressionsState = NIL; /* fetch index predicate if any */ ii->ii_Predicate = RelationGetIndexPredicate(index); ii->ii_PredicateState = NIL; /* other info */ ii->ii_Unique = indexStruct->indisunique; return ii; }
/* * get_relation_info - * Retrieves catalog information for a given relation. * * Given the Oid of the relation, return the following info into fields * of the RelOptInfo struct: * * min_attr lowest valid AttrNumber * max_attr highest valid AttrNumber * indexlist list of IndexOptInfos for relation's indexes * pages number of pages * tuples number of tuples * * Also, initialize the attr_needed[] and attr_widths[] arrays. In most * cases these are left as zeroes, but sometimes we need to compute attr * widths here, and we may as well cache the results for costsize.c. * * If inhparent is true, all we need to do is set up the attr arrays: * the RelOptInfo actually represents the appendrel formed by an inheritance * tree, and so the parent rel's physical size and index information isn't * important for it. */ void get_relation_info(PlannerInfo *root, Oid relationObjectId, bool inhparent, RelOptInfo *rel) { Index varno = rel->relid; Relation relation; bool hasindex; List *indexinfos = NIL; /* * We need not lock the relation since it was already locked, either by * the rewriter or when expand_inherited_rtentry() added it to the query's * rangetable. */ relation = heap_open(relationObjectId, NoLock); rel->min_attr = FirstLowInvalidHeapAttributeNumber + 1; rel->max_attr = RelationGetNumberOfAttributes(relation); rel->reltablespace = RelationGetForm(relation)->reltablespace; Assert(rel->max_attr >= rel->min_attr); rel->attr_needed = (Relids *) palloc0((rel->max_attr - rel->min_attr + 1) * sizeof(Relids)); rel->attr_widths = (int32 *) palloc0((rel->max_attr - rel->min_attr + 1) * sizeof(int32)); /* * Estimate relation size --- unless it's an inheritance parent, in which * case the size will be computed later in set_append_rel_pathlist, and we * must leave it zero for now to avoid bollixing the total_table_pages * calculation. */ if (!inhparent) estimate_rel_size(relation, rel->attr_widths - rel->min_attr, &rel->pages, &rel->tuples); /* * Make list of indexes. Ignore indexes on system catalogs if told to. * Don't bother with indexes for an inheritance parent, either. */ if (inhparent || (IgnoreSystemIndexes && IsSystemClass(relation->rd_rel))) hasindex = false; else hasindex = relation->rd_rel->relhasindex; if (hasindex) { List *indexoidlist; ListCell *l; LOCKMODE lmode; indexoidlist = RelationGetIndexList(relation); /* * For each index, we get the same type of lock that the executor will * need, and do not release it. This saves a couple of trips to the * shared lock manager while not creating any real loss of * concurrency, because no schema changes could be happening on the * index while we hold lock on the parent rel, and neither lock type * blocks any other kind of index operation. */ if (rel->relid == root->parse->resultRelation) lmode = RowExclusiveLock; else lmode = AccessShareLock; foreach(l, indexoidlist) { Oid indexoid = lfirst_oid(l); Relation indexRelation; Form_pg_index index; IndexOptInfo *info; int ncolumns; int i; /* * Extract info from the relation descriptor for the index. */ indexRelation = index_open(indexoid, lmode); index = indexRelation->rd_index; /* * Ignore invalid indexes, since they can't safely be used for * queries. Note that this is OK because the data structure we * are constructing is only used by the planner --- the executor * still needs to insert into "invalid" indexes! */ if (!index->indisvalid) { index_close(indexRelation, NoLock); continue; } /* * If the index is valid, but cannot yet be used, ignore it; but * mark the plan we are generating as transient. See * src/backend/access/heap/README.HOT for discussion. */ if (index->indcheckxmin && !TransactionIdPrecedes(HeapTupleHeaderGetXmin(indexRelation->rd_indextuple->t_data), TransactionXmin)) { root->glob->transientPlan = true; index_close(indexRelation, NoLock); continue; } info = makeNode(IndexOptInfo); info->indexoid = index->indexrelid; info->reltablespace = RelationGetForm(indexRelation)->reltablespace; info->rel = rel; info->ncolumns = ncolumns = index->indnatts; /* * Allocate per-column info arrays. To save a few palloc cycles * we allocate all the Oid-type arrays in one request. Note that * the opfamily array needs an extra, terminating zero at the end. * We pre-zero the ordering info in case the index is unordered. */ info->indexkeys = (int *) palloc(sizeof(int) * ncolumns); info->opfamily = (Oid *) palloc0(sizeof(Oid) * (4 * ncolumns + 1)); info->opcintype = info->opfamily + (ncolumns + 1); info->fwdsortop = info->opcintype + ncolumns; info->revsortop = info->fwdsortop + ncolumns; info->nulls_first = (bool *) palloc0(sizeof(bool) * ncolumns); for (i = 0; i < ncolumns; i++) { info->indexkeys[i] = index->indkey.values[i]; info->opfamily[i] = indexRelation->rd_opfamily[i]; info->opcintype[i] = indexRelation->rd_opcintype[i]; } info->relam = indexRelation->rd_rel->relam; info->amcostestimate = indexRelation->rd_am->amcostestimate; info->amoptionalkey = indexRelation->rd_am->amoptionalkey; info->amsearchnulls = indexRelation->rd_am->amsearchnulls; info->amhasgettuple = OidIsValid(indexRelation->rd_am->amgettuple); info->amhasgetbitmap = OidIsValid(indexRelation->rd_am->amgetbitmap); /* * Fetch the ordering operators associated with the index, if any. * We expect that all ordering-capable indexes use btree's * strategy numbers for the ordering operators. */ if (indexRelation->rd_am->amcanorder) { int nstrat = indexRelation->rd_am->amstrategies; for (i = 0; i < ncolumns; i++) { int16 opt = indexRelation->rd_indoption[i]; int fwdstrat; int revstrat; if (opt & INDOPTION_DESC) { fwdstrat = BTGreaterStrategyNumber; revstrat = BTLessStrategyNumber; } else { fwdstrat = BTLessStrategyNumber; revstrat = BTGreaterStrategyNumber; } /* * Index AM must have a fixed set of strategies for it to * make sense to specify amcanorder, so we need not allow * the case amstrategies == 0. */ if (fwdstrat > 0) { Assert(fwdstrat <= nstrat); info->fwdsortop[i] = indexRelation->rd_operator[i * nstrat + fwdstrat - 1]; } if (revstrat > 0) { Assert(revstrat <= nstrat); info->revsortop[i] = indexRelation->rd_operator[i * nstrat + revstrat - 1]; } info->nulls_first[i] = (opt & INDOPTION_NULLS_FIRST) != 0; } } /* * Fetch the index expressions and predicate, if any. We must * modify the copies we obtain from the relcache to have the * correct varno for the parent relation, so that they match up * correctly against qual clauses. */ info->indexprs = RelationGetIndexExpressions(indexRelation); info->indpred = RelationGetIndexPredicate(indexRelation); if (info->indexprs && varno != 1) ChangeVarNodes((Node *) info->indexprs, 1, varno, 0); if (info->indpred && varno != 1) ChangeVarNodes((Node *) info->indpred, 1, varno, 0); info->predOK = false; /* set later in indxpath.c */ info->unique = index->indisunique; /* * Estimate the index size. If it's not a partial index, we lock * the number-of-tuples estimate to equal the parent table; if it * is partial then we have to use the same methods as we would for * a table, except we can be sure that the index is not larger * than the table. */ if (info->indpred == NIL) { info->pages = RelationGetNumberOfBlocks(indexRelation); info->tuples = rel->tuples; } else { estimate_rel_size(indexRelation, NULL, &info->pages, &info->tuples); if (info->tuples > rel->tuples) info->tuples = rel->tuples; } index_close(indexRelation, NoLock); indexinfos = lcons(info, indexinfos); } list_free(indexoidlist); }
/* * get_relation_info - * Retrieves catalog information for a given relation. * * Given the Oid of the relation, return the following info into fields * of the RelOptInfo struct: * * min_attr lowest valid AttrNumber * max_attr highest valid AttrNumber * indexlist list of IndexOptInfos for relation's indexes * pages number of pages * tuples number of tuples * * Also, initialize the attr_needed[] and attr_widths[] arrays. In most * cases these are left as zeroes, but sometimes we need to compute attr * widths here, and we may as well cache the results for costsize.c. * * If inhparent is true, all we need to do is set up the attr arrays: * the RelOptInfo actually represents the appendrel formed by an inheritance * tree, and so the parent rel's physical size and index information isn't * important for it. */ void get_relation_info(PlannerInfo *root, Oid relationObjectId, bool inhparent, RelOptInfo *rel) { Index varno = rel->relid; Relation relation; bool hasindex; List *indexinfos = NIL; /* * We need not lock the relation since it was already locked, either by * the rewriter or when expand_inherited_rtentry() added it to the query's * rangetable. */ relation = heap_open(relationObjectId, NoLock); /* Temporary and unlogged relations are inaccessible during recovery. */ if (!RelationNeedsWAL(relation) && RecoveryInProgress()) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("cannot access temporary or unlogged relations during recovery"))); rel->min_attr = FirstLowInvalidHeapAttributeNumber + 1; rel->max_attr = RelationGetNumberOfAttributes(relation); rel->reltablespace = RelationGetForm(relation)->reltablespace; Assert(rel->max_attr >= rel->min_attr); rel->attr_needed = (Relids *) palloc0((rel->max_attr - rel->min_attr + 1) * sizeof(Relids)); rel->attr_widths = (int32 *) palloc0((rel->max_attr - rel->min_attr + 1) * sizeof(int32)); /* * Estimate relation size --- unless it's an inheritance parent, in which * case the size will be computed later in set_append_rel_pathlist, and we * must leave it zero for now to avoid bollixing the total_table_pages * calculation. */ if (!inhparent) estimate_rel_size(relation, rel->attr_widths - rel->min_attr, &rel->pages, &rel->tuples, &rel->allvisfrac); /* * Make list of indexes. Ignore indexes on system catalogs if told to. * Don't bother with indexes for an inheritance parent, either. */ if (inhparent || (IgnoreSystemIndexes && IsSystemClass(relation->rd_rel))) hasindex = false; else hasindex = relation->rd_rel->relhasindex; if (hasindex) { List *indexoidlist; ListCell *l; LOCKMODE lmode; indexoidlist = RelationGetIndexList(relation); /* * For each index, we get the same type of lock that the executor will * need, and do not release it. This saves a couple of trips to the * shared lock manager while not creating any real loss of * concurrency, because no schema changes could be happening on the * index while we hold lock on the parent rel, and neither lock type * blocks any other kind of index operation. */ if (rel->relid == root->parse->resultRelation) lmode = RowExclusiveLock; else lmode = AccessShareLock; foreach(l, indexoidlist) { Oid indexoid = lfirst_oid(l); Relation indexRelation; Form_pg_index index; IndexOptInfo *info; int ncolumns; int i; /* * Extract info from the relation descriptor for the index. */ indexRelation = index_open(indexoid, lmode); index = indexRelation->rd_index; /* * Ignore invalid indexes, since they can't safely be used for * queries. Note that this is OK because the data structure we * are constructing is only used by the planner --- the executor * still needs to insert into "invalid" indexes! */ if (!index->indisvalid) { index_close(indexRelation, NoLock); continue; } /* * If the index is valid, but cannot yet be used, ignore it; but * mark the plan we are generating as transient. See * src/backend/access/heap/README.HOT for discussion. */ if (index->indcheckxmin && !TransactionIdPrecedes(HeapTupleHeaderGetXmin(indexRelation->rd_indextuple->t_data), TransactionXmin)) { root->glob->transientPlan = true; index_close(indexRelation, NoLock); continue; } info = makeNode(IndexOptInfo); info->indexoid = index->indexrelid; info->reltablespace = RelationGetForm(indexRelation)->reltablespace; info->rel = rel; info->ncolumns = ncolumns = index->indnatts; info->indexkeys = (int *) palloc(sizeof(int) * ncolumns); info->indexcollations = (Oid *) palloc(sizeof(Oid) * ncolumns); info->opfamily = (Oid *) palloc(sizeof(Oid) * ncolumns); info->opcintype = (Oid *) palloc(sizeof(Oid) * ncolumns); for (i = 0; i < ncolumns; i++) { info->indexkeys[i] = index->indkey.values[i]; info->indexcollations[i] = indexRelation->rd_indcollation[i]; info->opfamily[i] = indexRelation->rd_opfamily[i]; info->opcintype[i] = indexRelation->rd_opcintype[i]; } info->relam = indexRelation->rd_rel->relam; info->amcostestimate = indexRelation->rd_am->amcostestimate; info->canreturn = index_can_return(indexRelation); info->amcanorderbyop = indexRelation->rd_am->amcanorderbyop; info->amoptionalkey = indexRelation->rd_am->amoptionalkey; info->amsearcharray = indexRelation->rd_am->amsearcharray; info->amsearchnulls = indexRelation->rd_am->amsearchnulls; info->amhasgettuple = OidIsValid(indexRelation->rd_am->amgettuple); info->amhasgetbitmap = OidIsValid(indexRelation->rd_am->amgetbitmap); /* * Fetch the ordering information for the index, if any. */ if (info->relam == BTREE_AM_OID) { /* * If it's a btree index, we can use its opfamily OIDs * directly as the sort ordering opfamily OIDs. */ Assert(indexRelation->rd_am->amcanorder); info->sortopfamily = info->opfamily; info->reverse_sort = (bool *) palloc(sizeof(bool) * ncolumns); info->nulls_first = (bool *) palloc(sizeof(bool) * ncolumns); for (i = 0; i < ncolumns; i++) { int16 opt = indexRelation->rd_indoption[i]; info->reverse_sort[i] = (opt & INDOPTION_DESC) != 0; info->nulls_first[i] = (opt & INDOPTION_NULLS_FIRST) != 0; } } else if (indexRelation->rd_am->amcanorder) { /* * Otherwise, identify the corresponding btree opfamilies by * trying to map this index's "<" operators into btree. Since * "<" uniquely defines the behavior of a sort order, this is * a sufficient test. * * XXX This method is rather slow and also requires the * undesirable assumption that the other index AM numbers its * strategies the same as btree. It'd be better to have a way * to explicitly declare the corresponding btree opfamily for * each opfamily of the other index type. But given the lack * of current or foreseeable amcanorder index types, it's not * worth expending more effort on now. */ info->sortopfamily = (Oid *) palloc(sizeof(Oid) * ncolumns); info->reverse_sort = (bool *) palloc(sizeof(bool) * ncolumns); info->nulls_first = (bool *) palloc(sizeof(bool) * ncolumns); for (i = 0; i < ncolumns; i++) { int16 opt = indexRelation->rd_indoption[i]; Oid ltopr; Oid btopfamily; Oid btopcintype; int16 btstrategy; info->reverse_sort[i] = (opt & INDOPTION_DESC) != 0; info->nulls_first[i] = (opt & INDOPTION_NULLS_FIRST) != 0; ltopr = get_opfamily_member(info->opfamily[i], info->opcintype[i], info->opcintype[i], BTLessStrategyNumber); if (OidIsValid(ltopr) && get_ordering_op_properties(ltopr, &btopfamily, &btopcintype, &btstrategy) && btopcintype == info->opcintype[i] && btstrategy == BTLessStrategyNumber) { /* Successful mapping */ info->sortopfamily[i] = btopfamily; } else { /* Fail ... quietly treat index as unordered */ info->sortopfamily = NULL; info->reverse_sort = NULL; info->nulls_first = NULL; break; } } } else { info->sortopfamily = NULL; info->reverse_sort = NULL; info->nulls_first = NULL; } /* * Fetch the index expressions and predicate, if any. We must * modify the copies we obtain from the relcache to have the * correct varno for the parent relation, so that they match up * correctly against qual clauses. */ info->indexprs = RelationGetIndexExpressions(indexRelation); info->indpred = RelationGetIndexPredicate(indexRelation); if (info->indexprs && varno != 1) ChangeVarNodes((Node *) info->indexprs, 1, varno, 0); if (info->indpred && varno != 1) ChangeVarNodes((Node *) info->indpred, 1, varno, 0); /* Build targetlist using the completed indexprs data */ info->indextlist = build_index_tlist(root, info, relation); info->predOK = false; /* set later in indxpath.c */ info->unique = index->indisunique; info->immediate = index->indimmediate; info->hypothetical = false; /* * Estimate the index size. If it's not a partial index, we lock * the number-of-tuples estimate to equal the parent table; if it * is partial then we have to use the same methods as we would for * a table, except we can be sure that the index is not larger * than the table. */ if (info->indpred == NIL) { info->pages = RelationGetNumberOfBlocks(indexRelation); info->tuples = rel->tuples; } else { double allvisfrac; /* dummy */ estimate_rel_size(indexRelation, NULL, &info->pages, &info->tuples, &allvisfrac); if (info->tuples > rel->tuples) info->tuples = rel->tuples; } index_close(indexRelation, NoLock); indexinfos = lcons(info, indexinfos); } list_free(indexoidlist); }
/* * refresh_by_match_merge * * Refresh a materialized view with transactional semantics, while allowing * concurrent reads. * * This is called after a new version of the data has been created in a * temporary table. It performs a full outer join against the old version of * the data, producing "diff" results. This join cannot work if there are any * duplicated rows in either the old or new versions, in the sense that every * column would compare as equal between the two rows. It does work correctly * in the face of rows which have at least one NULL value, with all non-NULL * columns equal. The behavior of NULLs on equality tests and on UNIQUE * indexes turns out to be quite convenient here; the tests we need to make * are consistent with default behavior. If there is at least one UNIQUE * index on the materialized view, we have exactly the guarantee we need. * * The temporary table used to hold the diff results contains just the TID of * the old record (if matched) and the ROW from the new table as a single * column of complex record type (if matched). * * Once we have the diff table, we perform set-based DELETE and INSERT * operations against the materialized view, and discard both temporary * tables. * * Everything from the generation of the new data to applying the differences * takes place under cover of an ExclusiveLock, since it seems as though we * would want to prohibit not only concurrent REFRESH operations, but also * incremental maintenance. It also doesn't seem reasonable or safe to allow * SELECT FOR UPDATE or SELECT FOR SHARE on rows being updated or deleted by * this command. */ static void refresh_by_match_merge(Oid matviewOid, Oid tempOid, Oid relowner, int save_sec_context) { StringInfoData querybuf; Relation matviewRel; Relation tempRel; char *matviewname; char *tempname; char *diffname; TupleDesc tupdesc; bool foundUniqueIndex; List *indexoidlist; ListCell *indexoidscan; int16 relnatts; bool *usedForQual; initStringInfo(&querybuf); matviewRel = heap_open(matviewOid, NoLock); matviewname = quote_qualified_identifier(get_namespace_name(RelationGetNamespace(matviewRel)), RelationGetRelationName(matviewRel)); tempRel = heap_open(tempOid, NoLock); tempname = quote_qualified_identifier(get_namespace_name(RelationGetNamespace(tempRel)), RelationGetRelationName(tempRel)); diffname = make_temptable_name_n(tempname, 2); relnatts = matviewRel->rd_rel->relnatts; usedForQual = (bool *) palloc0(sizeof(bool) * relnatts); /* Open SPI context. */ if (SPI_connect() != SPI_OK_CONNECT) elog(ERROR, "SPI_connect failed"); /* Analyze the temp table with the new contents. */ appendStringInfo(&querybuf, "ANALYZE %s", tempname); if (SPI_exec(querybuf.data, 0) != SPI_OK_UTILITY) elog(ERROR, "SPI_exec failed: %s", querybuf.data); /* * We need to ensure that there are not duplicate rows without NULLs in * the new data set before we can count on the "diff" results. Check for * that in a way that allows showing the first duplicated row found. Even * after we pass this test, a unique index on the materialized view may * find a duplicate key problem. */ resetStringInfo(&querybuf); appendStringInfo(&querybuf, "SELECT newdata FROM %s newdata " "WHERE newdata IS NOT NULL AND EXISTS " "(SELECT * FROM %s newdata2 WHERE newdata2 IS NOT NULL " "AND newdata2 OPERATOR(pg_catalog.*=) newdata " "AND newdata2.ctid OPERATOR(pg_catalog.<>) " "newdata.ctid) LIMIT 1", tempname, tempname); if (SPI_execute(querybuf.data, false, 1) != SPI_OK_SELECT) elog(ERROR, "SPI_exec failed: %s", querybuf.data); if (SPI_processed > 0) { ereport(ERROR, (errcode(ERRCODE_CARDINALITY_VIOLATION), errmsg("new data for \"%s\" contains duplicate rows without any null columns", RelationGetRelationName(matviewRel)), errdetail("Row: %s", SPI_getvalue(SPI_tuptable->vals[0], SPI_tuptable->tupdesc, 1)))); } SetUserIdAndSecContext(relowner, save_sec_context | SECURITY_LOCAL_USERID_CHANGE); /* Start building the query for creating the diff table. */ resetStringInfo(&querybuf); appendStringInfo(&querybuf, "CREATE TEMP TABLE %s AS " "SELECT mv.ctid AS tid, newdata " "FROM %s mv FULL JOIN %s newdata ON (", diffname, matviewname, tempname); /* * Get the list of index OIDs for the table from the relcache, and look up * each one in the pg_index syscache. We will test for equality on all * columns present in all unique indexes which only reference columns and * include all rows. */ tupdesc = matviewRel->rd_att; foundUniqueIndex = false; indexoidlist = RelationGetIndexList(matviewRel); foreach(indexoidscan, indexoidlist) { Oid indexoid = lfirst_oid(indexoidscan); Relation indexRel; Form_pg_index indexStruct; indexRel = index_open(indexoid, RowExclusiveLock); indexStruct = indexRel->rd_index; /* * We're only interested if it is unique, valid, contains no * expressions, and is not partial. */ if (indexStruct->indisunique && IndexIsValid(indexStruct) && RelationGetIndexExpressions(indexRel) == NIL && RelationGetIndexPredicate(indexRel) == NIL) { int numatts = indexStruct->indnatts; int i; /* Add quals for all columns from this index. */ for (i = 0; i < numatts; i++) { int attnum = indexStruct->indkey.values[i]; Oid type; Oid op; const char *colname; /* * Only include the column once regardless of how many times * it shows up in how many indexes. */ if (usedForQual[attnum - 1]) continue; usedForQual[attnum - 1] = true; /* * Actually add the qual, ANDed with any others. */ if (foundUniqueIndex) appendStringInfoString(&querybuf, " AND "); colname = quote_identifier(NameStr((tupdesc->attrs[attnum - 1])->attname)); appendStringInfo(&querybuf, "newdata.%s ", colname); type = attnumTypeId(matviewRel, attnum); op = lookup_type_cache(type, TYPECACHE_EQ_OPR)->eq_opr; mv_GenerateOper(&querybuf, op); appendStringInfo(&querybuf, " mv.%s", colname); foundUniqueIndex = true; } } /* Keep the locks, since we're about to run DML which needs them. */ index_close(indexRel, NoLock); }
/* * get_relation_info - * Retrieves catalog information for a given relation. * * Given the Oid of the relation, return the following info into fields * of the RelOptInfo struct: * * min_attr lowest valid AttrNumber * max_attr highest valid AttrNumber * indexlist list of IndexOptInfos for relation's indexes * pages number of pages * tuples number of tuples * * Also, initialize the attr_needed[] and attr_widths[] arrays. In most * cases these are left as zeroes, but sometimes we need to compute attr * widths here, and we may as well cache the results for costsize.c. */ void get_relation_info(Oid relationObjectId, RelOptInfo *rel) { Index varno = rel->relid; Relation relation; bool hasindex; List *indexinfos = NIL; /* * Normally, we can assume the rewriter already acquired at least * AccessShareLock on each relation used in the query. However this will * not be the case for relations added to the query because they are * inheritance children of some relation mentioned explicitly. For them, * this is the first access during the parse/rewrite/plan pipeline, and so * we need to obtain and keep a suitable lock. * * XXX really, a suitable lock is RowShareLock if the relation is an * UPDATE/DELETE target, and AccessShareLock otherwise. However we cannot * easily tell here which to get, so for the moment just get * AccessShareLock always. The executor will get the right lock when it * runs, which means there is a very small chance of deadlock trying to * upgrade our lock. */ if (rel->reloptkind == RELOPT_BASEREL) relation = heap_open(relationObjectId, NoLock); else relation = heap_open(relationObjectId, AccessShareLock); rel->min_attr = FirstLowInvalidHeapAttributeNumber + 1; rel->max_attr = RelationGetNumberOfAttributes(relation); Assert(rel->max_attr >= rel->min_attr); rel->attr_needed = (Relids *) palloc0((rel->max_attr - rel->min_attr + 1) * sizeof(Relids)); rel->attr_widths = (int32 *) palloc0((rel->max_attr - rel->min_attr + 1) * sizeof(int32)); /* * Estimate relation size. */ estimate_rel_size(relation, rel->attr_widths - rel->min_attr, &rel->pages, &rel->tuples); /* * Make list of indexes. Ignore indexes on system catalogs if told to. */ if (IsIgnoringSystemIndexes() && IsSystemClass(relation->rd_rel)) hasindex = false; else hasindex = relation->rd_rel->relhasindex; if (hasindex) { List *indexoidlist; ListCell *l; indexoidlist = RelationGetIndexList(relation); foreach(l, indexoidlist) { Oid indexoid = lfirst_oid(l); Relation indexRelation; Form_pg_index index; IndexOptInfo *info; int ncolumns; int i; int16 amorderstrategy; /* * Extract info from the relation descriptor for the index. * * Note that we take no lock on the index; we assume our lock on * the parent table will protect the index's schema information. * When and if the executor actually uses the index, it will take * a lock as needed to protect the access to the index contents. */ indexRelation = index_open(indexoid); index = indexRelation->rd_index; info = makeNode(IndexOptInfo); info->indexoid = index->indexrelid; info->rel = rel; info->ncolumns = ncolumns = index->indnatts; /* * Need to make classlist and ordering arrays large enough to put * a terminating 0 at the end of each one. */ info->indexkeys = (int *) palloc(sizeof(int) * ncolumns); info->classlist = (Oid *) palloc0(sizeof(Oid) * (ncolumns + 1)); info->ordering = (Oid *) palloc0(sizeof(Oid) * (ncolumns + 1)); for (i = 0; i < ncolumns; i++) { info->classlist[i] = indexRelation->rd_indclass->values[i]; info->indexkeys[i] = index->indkey.values[i]; } info->relam = indexRelation->rd_rel->relam; info->amcostestimate = indexRelation->rd_am->amcostestimate; info->amoptionalkey = indexRelation->rd_am->amoptionalkey; /* * Fetch the ordering operators associated with the index, if any. */ amorderstrategy = indexRelation->rd_am->amorderstrategy; if (amorderstrategy != 0) { int oprindex = amorderstrategy - 1; for (i = 0; i < ncolumns; i++) { info->ordering[i] = indexRelation->rd_operator[oprindex]; oprindex += indexRelation->rd_am->amstrategies; } } /* * Fetch the index expressions and predicate, if any. We must * modify the copies we obtain from the relcache to have the * correct varno for the parent relation, so that they match up * correctly against qual clauses. */ info->indexprs = RelationGetIndexExpressions(indexRelation); info->indpred = RelationGetIndexPredicate(indexRelation); if (info->indexprs && varno != 1) ChangeVarNodes((Node *) info->indexprs, 1, varno, 0); if (info->indpred && varno != 1) ChangeVarNodes((Node *) info->indpred, 1, varno, 0); info->predOK = false; /* set later in indxpath.c */ info->unique = index->indisunique; /* * Estimate the index size. If it's not a partial index, we lock * the number-of-tuples estimate to equal the parent table; if it * is partial then we have to use the same methods as we would for * a table, except we can be sure that the index is not larger * than the table. */ if (info->indpred == NIL) { info->pages = RelationGetNumberOfBlocks(indexRelation); info->tuples = rel->tuples; } else { estimate_rel_size(indexRelation, NULL, &info->pages, &info->tuples); if (info->tuples > rel->tuples) info->tuples = rel->tuples; } index_close(indexRelation); indexinfos = lcons(info, indexinfos); } list_free(indexoidlist); }
/* * get_relation_info - * Retrieves catalog information for a given relation. * * Given the Oid of the relation, return the following info into fields * of the RelOptInfo struct: * * min_attr lowest valid AttrNumber * max_attr highest valid AttrNumber * indexlist list of IndexOptInfos for relation's indexes * pages number of pages * tuples number of tuples * * Also, initialize the attr_needed[] and attr_widths[] arrays. In most * cases these are left as zeroes, but sometimes we need to compute attr * widths here, and we may as well cache the results for costsize.c. * * If inhparent is true, all we need to do is set up the attr arrays: * the RelOptInfo actually represents the appendrel formed by an inheritance * tree, and so the parent rel's physical size and index information isn't * important for it. */ void get_relation_info(PlannerInfo *root, Oid relationObjectId, bool inhparent, RelOptInfo *rel) { Index varno = rel->relid; Relation relation; bool hasindex; List *indexinfos = NIL; bool needs_longlock; /* * We need not lock the relation since it was already locked, either by * the rewriter or when expand_inherited_rtentry() added it to the query's * rangetable. */ relation = heap_open(relationObjectId, NoLock); needs_longlock = rel_needs_long_lock(relationObjectId); rel->min_attr = FirstLowInvalidHeapAttributeNumber + 1; rel->max_attr = RelationGetNumberOfAttributes(relation); Assert(rel->max_attr >= rel->min_attr); rel->attr_needed = (Relids *) palloc0((rel->max_attr - rel->min_attr + 1) * sizeof(Relids)); rel->attr_widths = (int32 *) palloc0((rel->max_attr - rel->min_attr + 1) * sizeof(int32)); /* * CDB: Get partitioning key info for distributed relation. */ rel->cdbpolicy = RelationGetPartitioningKey(relation); /* * Estimate relation size --- unless it's an inheritance parent, in which * case the size will be computed later in set_append_rel_pathlist, and we * must leave it zero for now to avoid bollixing the total_table_pages * calculation. */ if (!inhparent) { cdb_estimate_rel_size ( rel, relation, relation, rel->attr_widths - rel->min_attr, &rel->pages, &rel->tuples, &rel->cdb_default_stats_used ); } /* * Make list of indexes. Ignore indexes on system catalogs if told to. * Don't bother with indexes for an inheritance parent, either. */ if (inhparent || (IgnoreSystemIndexes && IsSystemClass(relation->rd_rel))) hasindex = false; else hasindex = relation->rd_rel->relhasindex; if (hasindex) { List *indexoidlist; ListCell *l; LOCKMODE lmode; /* Warn if indexed table needs ANALYZE. */ if (rel->cdb_default_stats_used) cdb_default_stats_warning_for_table(relation->rd_id); indexoidlist = RelationGetIndexList(relation); /* * For each index, we get the same type of lock that the executor will * need, and do not release it. This saves a couple of trips to the * shared lock manager while not creating any real loss of * concurrency, because no schema changes could be happening on the * index while we hold lock on the parent rel, and neither lock type * blocks any other kind of index operation. */ if (rel->relid == root->parse->resultRelation) lmode = RowExclusiveLock; else lmode = AccessShareLock; foreach(l, indexoidlist) { Oid indexoid = lfirst_oid(l); Relation indexRelation; Form_pg_index index; IndexOptInfo *info; int ncolumns; int i; int16 amorderstrategy; /* * Extract info from the relation descriptor for the index. */ indexRelation = index_open(indexoid, lmode); index = indexRelation->rd_index; /* * Ignore invalid indexes, since they can't safely be used for * queries. Note that this is OK because the data structure we * are constructing is only used by the planner --- the executor * still needs to insert into "invalid" indexes! */ if (!index->indisvalid) { index_close(indexRelation, NoLock); continue; } info = makeNode(IndexOptInfo); info->indexoid = index->indexrelid; info->rel = rel; info->ncolumns = ncolumns = index->indnatts; /* * Need to make classlist and ordering arrays large enough to put * a terminating 0 at the end of each one. */ info->indexkeys = (int *) palloc(sizeof(int) * ncolumns); info->classlist = (Oid *) palloc0(sizeof(Oid) * (ncolumns + 1)); info->ordering = (Oid *) palloc0(sizeof(Oid) * (ncolumns + 1)); for (i = 0; i < ncolumns; i++) { info->classlist[i] = indexRelation->rd_indclass->values[i]; info->indexkeys[i] = index->indkey.values[i]; } info->relam = indexRelation->rd_rel->relam; info->amcostestimate = indexRelation->rd_am->amcostestimate; info->amoptionalkey = indexRelation->rd_am->amoptionalkey; /* * Fetch the ordering operators associated with the index, if any. */ amorderstrategy = indexRelation->rd_am->amorderstrategy; if (amorderstrategy != 0) { int oprindex = amorderstrategy - 1; for (i = 0; i < ncolumns; i++) { info->ordering[i] = indexRelation->rd_operator[oprindex]; oprindex += indexRelation->rd_am->amstrategies; } } /* * Fetch the index expressions and predicate, if any. We must * modify the copies we obtain from the relcache to have the * correct varno for the parent relation, so that they match up * correctly against qual clauses. */ info->indexprs = RelationGetIndexExpressions(indexRelation); info->indpred = RelationGetIndexPredicate(indexRelation); if (info->indexprs && varno != 1) ChangeVarNodes((Node *) info->indexprs, 1, varno, 0); if (info->indpred && varno != 1) ChangeVarNodes((Node *) info->indpred, 1, varno, 0); info->predOK = false; /* set later in indxpath.c */ info->unique = index->indisunique; /* * Estimate the index size. If it's not a partial index, we lock * the number-of-tuples estimate to equal the parent table; if it * is partial then we have to use the same methods as we would for * a table, except we can be sure that the index is not larger * than the table. */ cdb_estimate_rel_size(rel, relation, indexRelation, NULL, &info->pages, &info->tuples, &info->cdb_default_stats_used); if (!info->indpred || info->tuples > rel->tuples) info->tuples = rel->tuples; if (info->cdb_default_stats_used && !rel->cdb_default_stats_used) cdb_default_stats_warning_for_index(relation->rd_id, indexoid); index_close(indexRelation, needs_longlock ? NoLock : lmode); indexinfos = lcons(info, indexinfos); } list_free(indexoidlist); }
/* * ExecRefreshMatView -- execute a REFRESH MATERIALIZED VIEW command * * This refreshes the materialized view by creating a new table and swapping * the relfilenodes of the new table and the old materialized view, so the OID * of the original materialized view is preserved. Thus we do not lose GRANT * nor references to this materialized view. * * If WITH NO DATA was specified, this is effectively like a TRUNCATE; * otherwise it is like a TRUNCATE followed by an INSERT using the SELECT * statement associated with the materialized view. The statement node's * skipData field shows whether the clause was used. * * Indexes are rebuilt too, via REINDEX. Since we are effectively bulk-loading * the new heap, it's better to create the indexes afterwards than to fill them * incrementally while we load. * * The matview's "populated" state is changed based on whether the contents * reflect the result set of the materialized view's query. */ ObjectAddress ExecRefreshMatView(RefreshMatViewStmt *stmt, const char *queryString, ParamListInfo params, char *completionTag) { Oid matviewOid; Relation matviewRel; RewriteRule *rule; List *actions; Query *dataQuery; Oid tableSpace; Oid relowner; Oid OIDNewHeap; DestReceiver *dest; bool concurrent; LOCKMODE lockmode; char relpersistence; Oid save_userid; int save_sec_context; int save_nestlevel; ObjectAddress address; /* Determine strength of lock needed. */ concurrent = stmt->concurrent; lockmode = concurrent ? ExclusiveLock : AccessExclusiveLock; /* * Get a lock until end of transaction. */ matviewOid = RangeVarGetRelidExtended(stmt->relation, lockmode, false, false, RangeVarCallbackOwnsTable, NULL); matviewRel = heap_open(matviewOid, NoLock); /* Make sure it is a materialized view. */ if (matviewRel->rd_rel->relkind != RELKIND_MATVIEW) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("\"%s\" is not a materialized view", RelationGetRelationName(matviewRel)))); /* Check that CONCURRENTLY is not specified if not populated. */ if (concurrent && !RelationIsPopulated(matviewRel)) ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), errmsg("CONCURRENTLY cannot be used when the materialized view is not populated"))); /* Check that conflicting options have not been specified. */ if (concurrent && stmt->skipData) ereport(ERROR, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("CONCURRENTLY and WITH NO DATA options cannot be used together"))); /* We don't allow an oid column for a materialized view. */ Assert(!matviewRel->rd_rel->relhasoids); /* * Check that everything is correct for a refresh. Problems at this point * are internal errors, so elog is sufficient. */ if (matviewRel->rd_rel->relhasrules == false || matviewRel->rd_rules->numLocks < 1) elog(ERROR, "materialized view \"%s\" is missing rewrite information", RelationGetRelationName(matviewRel)); if (matviewRel->rd_rules->numLocks > 1) elog(ERROR, "materialized view \"%s\" has too many rules", RelationGetRelationName(matviewRel)); rule = matviewRel->rd_rules->rules[0]; if (rule->event != CMD_SELECT || !(rule->isInstead)) elog(ERROR, "the rule for materialized view \"%s\" is not a SELECT INSTEAD OF rule", RelationGetRelationName(matviewRel)); actions = rule->actions; if (list_length(actions) != 1) elog(ERROR, "the rule for materialized view \"%s\" is not a single action", RelationGetRelationName(matviewRel)); /* * Check that there is a unique index with no WHERE clause on * one or more columns of the materialized view if CONCURRENTLY * is specified. */ if (concurrent) { List *indexoidlist = RelationGetIndexList(matviewRel); ListCell *indexoidscan; bool hasUniqueIndex = false; foreach(indexoidscan, indexoidlist) { Oid indexoid = lfirst_oid(indexoidscan); Relation indexRel; Form_pg_index indexStruct; indexRel = index_open(indexoid, AccessShareLock); indexStruct = indexRel->rd_index; if (indexStruct->indisunique && IndexIsValid(indexStruct) && RelationGetIndexExpressions(indexRel) == NIL && RelationGetIndexPredicate(indexRel) == NIL && indexStruct->indnatts > 0) { hasUniqueIndex = true; index_close(indexRel, AccessShareLock); break; } index_close(indexRel, AccessShareLock); } list_free(indexoidlist); if (!hasUniqueIndex) ereport(ERROR, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("cannot refresh materialized view \"%s\" concurrently", quote_qualified_identifier(get_namespace_name(RelationGetNamespace(matviewRel)), RelationGetRelationName(matviewRel))), errhint("Create a unique index with no WHERE clause on one or more columns of the materialized view."))); }