diff options
Diffstat (limited to 'src/backend/parser/parse_clause.c')
| -rw-r--r-- | src/backend/parser/parse_clause.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/src/backend/parser/parse_clause.c b/src/backend/parser/parse_clause.c index 73c505ed85b..6b1bbe57d0e 100644 --- a/src/backend/parser/parse_clause.c +++ b/src/backend/parser/parse_clause.c @@ -17,6 +17,7 @@ #include "access/heapam.h" #include "catalog/catalog.h" +#include "access/htup_details.h" #include "catalog/heap.h" #include "catalog/pg_constraint.h" #include "catalog/pg_type.h" @@ -31,6 +32,7 @@ #include "parser/parse_coerce.h" #include "parser/parse_collate.h" #include "parser/parse_expr.h" +#include "parser/parse_func.h" #include "parser/parse_oper.h" #include "parser/parse_relation.h" #include "parser/parse_target.h" @@ -39,6 +41,7 @@ #include "utils/guc.h" #include "utils/lsyscache.h" #include "utils/rel.h" +#include "utils/syscache.h" /* Convenience macro for the most common makeNamespaceItem() case */ @@ -419,6 +422,39 @@ transformJoinOnClause(ParseState *pstate, JoinExpr *j, List *namespace) return result; } +static RangeTblEntry * +transformTableSampleEntry(ParseState *pstate, RangeTableSample *rv) +{ + RangeTblEntry *rte = NULL; + CommonTableExpr *cte = NULL; + TableSampleClause *tablesample = NULL; + + /* if relation has an unqualified name, it might be a CTE reference */ + if (!rv->relation->schemaname) + { + Index levelsup; + cte = scanNameSpaceForCTE(pstate, rv->relation->relname, &levelsup); + } + + /* We first need to build a range table entry */ + if (!cte) + rte = transformTableEntry(pstate, rv->relation); + + if (!rte || + (rte->relkind != RELKIND_RELATION && + rte->relkind != RELKIND_MATVIEW)) + ereport(ERROR, + (errcode(ERRCODE_SYNTAX_ERROR), + errmsg("TABLESAMPLE clause can only be used on tables and materialized views"), + parser_errposition(pstate, rv->relation->location))); + + tablesample = ParseTableSample(pstate, rv->method, rv->repeatable, + rv->args, rv->relation->location); + rte->tablesample = tablesample; + + return rte; +} + /* * transformTableEntry --- transform a RangeVar (simple relation reference) */ @@ -1127,6 +1163,26 @@ transformFromClauseItem(ParseState *pstate, Node *n, return (Node *) j; } + else if (IsA(n, RangeTableSample)) + { + /* Tablesample reference */ + RangeTableSample *rv = (RangeTableSample *) n; + RangeTblRef *rtr; + RangeTblEntry *rte = NULL; + int rtindex; + + rte = transformTableSampleEntry(pstate, rv); + + /* assume new rte is at end */ + rtindex = list_length(pstate->p_rtable); + Assert(rte == rt_fetch(rtindex, pstate->p_rtable)); + *top_rte = rte; + *top_rti = rtindex; + *namespace = list_make1(makeDefaultNSItem(rte)); + rtr = makeNode(RangeTblRef); + rtr->rtindex = rtindex; + return (Node *) rtr; + } else elog(ERROR, "unrecognized node type: %d", (int) nodeTag(n)); return NULL; /* can't get here, keep compiler quiet */ |