diff options
Diffstat (limited to 'src/backend/utils/adt/arraysubs.c')
| -rw-r--r-- | src/backend/utils/adt/arraysubs.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/src/backend/utils/adt/arraysubs.c b/src/backend/utils/adt/arraysubs.c index 562179b3799..2940fb8e8d7 100644 --- a/src/backend/utils/adt/arraysubs.c +++ b/src/backend/utils/adt/arraysubs.c @@ -18,6 +18,7 @@ #include "nodes/makefuncs.h" #include "nodes/nodeFuncs.h" #include "nodes/subscripting.h" +#include "nodes/supportnodes.h" #include "parser/parse_coerce.h" #include "parser/parse_expr.h" #include "utils/array.h" @@ -575,3 +576,36 @@ raw_array_subscript_handler(PG_FUNCTION_ARGS) PG_RETURN_POINTER(&sbsroutines); } + +/* + * array_subscript_handler_support() + * + * Planner support function for array_subscript_handler() + */ +Datum +array_subscript_handler_support(PG_FUNCTION_ARGS) +{ + Node *rawreq = (Node *) PG_GETARG_POINTER(0); + Node *ret = NULL; + + if (IsA(rawreq, SupportRequestModifyInPlace)) + { + /* + * We can optimize in-place subscripted assignment if the refexpr is + * the array being assigned to. We don't need to worry about array + * references within the refassgnexpr or the subscripts; however, if + * there's no refassgnexpr then it's a fetch which there's no need to + * optimize. + */ + SupportRequestModifyInPlace *req = (SupportRequestModifyInPlace *) rawreq; + Param *refexpr = (Param *) linitial(req->args); + + if (refexpr && IsA(refexpr, Param) && + refexpr->paramkind == PARAM_EXTERN && + refexpr->paramid == req->paramid && + lsecond(req->args) != NULL) + ret = (Node *) refexpr; + } + + PG_RETURN_POINTER(ret); +} |