diff options
Diffstat (limited to 'src/backend/utils/adt/int8.c')
| -rw-r--r-- | src/backend/utils/adt/int8.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/src/backend/utils/adt/int8.c b/src/backend/utils/adt/int8.c index 4a87114a4f4..98d43237556 100644 --- a/src/backend/utils/adt/int8.c +++ b/src/backend/utils/adt/int8.c @@ -24,6 +24,7 @@ #include "nodes/supportnodes.h" #include "optimizer/optimizer.h" #include "utils/builtins.h" +#include "utils/lsyscache.h" typedef struct @@ -818,6 +819,49 @@ int8dec_any(PG_FUNCTION_ARGS) return int8dec(fcinfo); } +/* + * int8inc_support + * prosupport function for int8inc() and int8inc_any() + */ +Datum +int8inc_support(PG_FUNCTION_ARGS) +{ + Node *rawreq = (Node *) PG_GETARG_POINTER(0); + + if (IsA(rawreq, SupportRequestWFuncMonotonic)) + { + SupportRequestWFuncMonotonic *req = (SupportRequestWFuncMonotonic *) rawreq; + MonotonicFunction monotonic = MONOTONICFUNC_NONE; + int frameOptions = req->window_clause->frameOptions; + + /* No ORDER BY clause then all rows are peers */ + if (req->window_clause->orderClause == NIL) + monotonic = MONOTONICFUNC_BOTH; + else + { + /* + * Otherwise take into account the frame options. When the frame + * bound is the start of the window then the resulting value can + * never decrease, therefore is monotonically increasing + */ + if (frameOptions & FRAMEOPTION_START_UNBOUNDED_PRECEDING) + monotonic |= MONOTONICFUNC_INCREASING; + + /* + * Likewise, if the frame bound is the end of the window then the + * resulting value can never decrease. + */ + if (frameOptions & FRAMEOPTION_END_UNBOUNDED_FOLLOWING) + monotonic |= MONOTONICFUNC_DECREASING; + } + + req->monotonic = monotonic; + PG_RETURN_POINTER(req); + } + + PG_RETURN_POINTER(NULL); +} + Datum int8larger(PG_FUNCTION_ARGS) |