diff options
Diffstat (limited to 'contrib/postgres_fdw/deparse.c')
| -rw-r--r-- | contrib/postgres_fdw/deparse.c | 127 |
1 files changed, 76 insertions, 51 deletions
diff --git a/contrib/postgres_fdw/deparse.c b/contrib/postgres_fdw/deparse.c index e577a039566..df3d1ee1846 100644 --- a/contrib/postgres_fdw/deparse.c +++ b/contrib/postgres_fdw/deparse.c @@ -141,6 +141,11 @@ static void printRemoteParam(int paramindex, Oid paramtype, int32 paramtypmod, deparse_expr_cxt *context); static void printRemotePlaceholder(Oid paramtype, int32 paramtypmod, deparse_expr_cxt *context); +static void deparseSelectSql(Bitmapset *attrs_used, List **retrieved_attrs, + deparse_expr_cxt *context); +static void deparseLockingClause(deparse_expr_cxt *context); +static void appendWhereClause(List *exprs, deparse_expr_cxt *context); +static void appendOrderByClause(List *pathkeys, deparse_expr_cxt *context); /* @@ -697,6 +702,51 @@ deparse_type_name(Oid type_oid, int32 typemod) return format_type_with_typemod_qualified(type_oid, typemod); } +/* + * Deparse SELECT statement for given relation into buf. + * + * remote_conds is the list of conditions to be deparsed as WHERE clause. + * + * pathkeys is the list of pathkeys to order the result by. + * + * List of columns selected is returned in retrieved_attrs. + * + * If params_list is not NULL, it receives a list of Params and other-relation + * Vars used in the clauses; these values must be transmitted to the remote + * server as parameter values. + * + * If params_list is NULL, we're generating the query for EXPLAIN purposes, + * so Params and other-relation Vars should be replaced by dummy values. + */ +extern void +deparseSelectStmtForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *rel, + List *remote_conds, List *pathkeys, + List **retrieved_attrs, List **params_list) +{ + PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) rel->fdw_private; + deparse_expr_cxt context; + + /* Initialize params_list if caller needs one */ + if (params_list) + *params_list = NIL; + + context.buf = buf; + context.root = root; + context.foreignrel = rel; + context.params_list = params_list; + + deparseSelectSql(fpinfo->attrs_used, retrieved_attrs, &context); + + if (remote_conds) + appendWhereClause(remote_conds, &context); + + /* Add ORDER BY clause if we found any useful pathkeys */ + if (pathkeys) + appendOrderByClause(pathkeys, &context); + + /* Add any necessary FOR UPDATE/SHARE. */ + deparseLockingClause(&context); +} /* * Construct a simple SELECT statement that retrieves desired columns @@ -707,13 +757,13 @@ deparse_type_name(Oid type_oid, int32 typemod) * returned to *retrieved_attrs. */ void -deparseSelectSql(StringInfo buf, - PlannerInfo *root, - RelOptInfo *baserel, - Bitmapset *attrs_used, - List **retrieved_attrs) +deparseSelectSql(Bitmapset *attrs_used, List **retrieved_attrs, + deparse_expr_cxt *context) { - RangeTblEntry *rte = planner_rt_fetch(baserel->relid, root); + StringInfo buf = context->buf; + RelOptInfo *foreignrel = context->foreignrel; + PlannerInfo *root = context->root; + RangeTblEntry *rte = planner_rt_fetch(foreignrel->relid, root); Relation rel; /* @@ -726,7 +776,7 @@ deparseSelectSql(StringInfo buf, * Construct SELECT list */ appendStringInfoString(buf, "SELECT "); - deparseTargetList(buf, root, baserel->relid, rel, attrs_used, + deparseTargetList(buf, root, foreignrel->relid, rel, attrs_used, retrieved_attrs); /* @@ -811,11 +861,15 @@ deparseTargetList(StringInfo buf, /* * Deparse the appropriate locking clause (FOR SELECT or FOR SHARE) for a - * given relation. + * given relation (context->foreignrel). */ -void -deparseLockingClause(StringInfo buf, PlannerInfo *root, RelOptInfo *rel) +static void +deparseLockingClause(deparse_expr_cxt *context) { + StringInfo buf = context->buf; + PlannerInfo *root = context->root; + RelOptInfo *rel = context->foreignrel; + /* * Add FOR UPDATE/SHARE if appropriate. We apply locking during the * initial row fetch, rather than later on as is done for local tables. @@ -868,39 +922,16 @@ deparseLockingClause(StringInfo buf, PlannerInfo *root, RelOptInfo *rel) } /* - * Deparse WHERE clauses in given list of RestrictInfos and append them to buf. - * - * baserel is the foreign table we're planning for. - * - * If no WHERE clause already exists in the buffer, is_first should be true. - * - * If params is not NULL, it receives a list of Params and other-relation Vars - * used in the clauses; these values must be transmitted to the remote server - * as parameter values. - * - * If params is NULL, we're generating the query for EXPLAIN purposes, - * so Params and other-relation Vars should be replaced by dummy values. + * Deparse WHERE clauses in given list of RestrictInfos and append them to + * context->buf. */ -void -appendWhereClause(StringInfo buf, - PlannerInfo *root, - RelOptInfo *baserel, - List *exprs, - bool is_first, - List **params) +static void +appendWhereClause(List *exprs, deparse_expr_cxt *context) { - deparse_expr_cxt context; int nestlevel; ListCell *lc; - - if (params) - *params = NIL; /* initialize result list to empty */ - - /* Set up context struct for recursion */ - context.root = root; - context.foreignrel = baserel; - context.buf = buf; - context.params_list = params; + bool is_first = true; + StringInfo buf = context->buf; /* Make sure any constants in the exprs are printed portably */ nestlevel = set_transmission_modes(); @@ -916,7 +947,7 @@ appendWhereClause(StringInfo buf, appendStringInfoString(buf, " AND "); appendStringInfoChar(buf, '('); - deparseExpr(ri->clause, &context); + deparseExpr(ri->clause, context); appendStringInfoChar(buf, ')'); is_first = false; @@ -1946,20 +1977,14 @@ printRemotePlaceholder(Oid paramtype, int32 paramtypmod, * relation. From given pathkeys expressions belonging entirely to the given * base relation are obtained and deparsed. */ -void -appendOrderByClause(StringInfo buf, PlannerInfo *root, RelOptInfo *baserel, - List *pathkeys) +static void +appendOrderByClause(List *pathkeys, deparse_expr_cxt *context) { ListCell *lcell; - deparse_expr_cxt context; int nestlevel; char *delim = " "; - - /* Set up context struct for recursion */ - context.root = root; - context.foreignrel = baserel; - context.buf = buf; - context.params_list = NULL; + RelOptInfo *baserel = context->foreignrel; + StringInfo buf = context->buf; /* Make sure any constants in the exprs are printed portably */ nestlevel = set_transmission_modes(); @@ -1974,7 +1999,7 @@ appendOrderByClause(StringInfo buf, PlannerInfo *root, RelOptInfo *baserel, Assert(em_expr != NULL); appendStringInfoString(buf, delim); - deparseExpr(em_expr, &context); + deparseExpr(em_expr, context); if (pathkey->pk_strategy == BTLessStrategyNumber) appendStringInfoString(buf, " ASC"); else |