diff options
Diffstat (limited to 'contrib/postgres_fdw/deparse.c')
| -rw-r--r-- | contrib/postgres_fdw/deparse.c | 56 |
1 files changed, 53 insertions, 3 deletions
diff --git a/contrib/postgres_fdw/deparse.c b/contrib/postgres_fdw/deparse.c index 697de60dfe5..3cb728fa693 100644 --- a/contrib/postgres_fdw/deparse.c +++ b/contrib/postgres_fdw/deparse.c @@ -193,9 +193,12 @@ is_foreign_expr(PlannerInfo *root, if (!foreign_expr_walker((Node *) expr, &glob_cxt, &loc_cxt)) return false; - /* Expressions examined here should be boolean, ie noncollatable */ - Assert(loc_cxt.collation == InvalidOid); - Assert(loc_cxt.state == FDW_COLLATE_NONE); + /* + * If the expression has a valid collation that does not arise from a + * foreign var, the expression can not be sent over. + */ + if (loc_cxt.state == FDW_COLLATE_UNSAFE) + return false; /* * An expression which includes any mutable functions can't be sent over @@ -1877,3 +1880,50 @@ printRemotePlaceholder(Oid paramtype, int32 paramtypmod, appendStringInfo(buf, "((SELECT null::%s)::%s)", ptypename, ptypename); } + +/* + * Deparse ORDER BY clause according to the given pathkeys for given base + * 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) +{ + 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; + + /* Make sure any constants in the exprs are printed portably */ + nestlevel = set_transmission_modes(); + + appendStringInfo(buf, " ORDER BY"); + foreach(lcell, pathkeys) + { + PathKey *pathkey = lfirst(lcell); + Expr *em_expr; + + em_expr = find_em_expr_for_rel(pathkey->pk_eclass, baserel); + Assert(em_expr != NULL); + + appendStringInfoString(buf, delim); + deparseExpr(em_expr, &context); + if (pathkey->pk_strategy == BTLessStrategyNumber) + appendStringInfoString(buf, " ASC"); + else + appendStringInfoString(buf, " DESC"); + + if (pathkey->pk_nulls_first) + appendStringInfoString(buf, " NULLS FIRST"); + + delim = ", "; + } + reset_transmission_modes(nestlevel); +} |