diff options
Diffstat (limited to 'src/backend/executor/nodeWindowAgg.c')
| -rw-r--r-- | src/backend/executor/nodeWindowAgg.c | 34 |
1 files changed, 16 insertions, 18 deletions
diff --git a/src/backend/executor/nodeWindowAgg.c b/src/backend/executor/nodeWindowAgg.c index 0698aae37a7..e6a53f95391 100644 --- a/src/backend/executor/nodeWindowAgg.c +++ b/src/backend/executor/nodeWindowAgg.c @@ -3271,7 +3271,7 @@ window_gettupleslot(WindowObject winobj, int64 pos, TupleTableSlot *slot) } /* - * get tupple and evaluate in a partition + * get tuple and evaluate in partition */ static Datum gettuple_eval_partition(WindowObject winobj, int argno, @@ -3718,7 +3718,7 @@ WinGetFuncArgInPartition(WindowObject winobj, int argno, WindowAggState *winstate; int64 abs_pos; Datum datum; - bool null_treatment = false; + bool null_treatment; int notnull_offset; int notnull_relpos; int forward; @@ -3727,13 +3727,7 @@ WinGetFuncArgInPartition(WindowObject winobj, int argno, Assert(WindowObjectIsValid(winobj)); winstate = winobj->winstate; - if (winobj->ignore_nulls == IGNORE_NULLS && relpos != 0) - { - null_treatment = true; - notnull_offset = 0; - notnull_relpos = abs(relpos); - forward = relpos > 0 ? 1 : -1; - } + null_treatment = (winobj->ignore_nulls == IGNORE_NULLS && relpos != 0); switch (seektype) { @@ -3759,9 +3753,10 @@ WinGetFuncArgInPartition(WindowObject winobj, int argno, break; } - if (!null_treatment) /* IGNORE NULLS is not specified */ + /* Easy case if IGNORE NULLS is not specified */ + if (!null_treatment) { - /* get tupple and evaluate in a partition */ + /* get tuple and evaluate in partition */ datum = gettuple_eval_partition(winobj, argno, abs_pos, isnull, &myisout); if (!myisout && set_mark) @@ -3771,32 +3766,35 @@ WinGetFuncArgInPartition(WindowObject winobj, int argno, return datum; } + /* Prepare for loop */ + notnull_offset = 0; + notnull_relpos = abs(relpos); + forward = relpos > 0 ? 1 : -1; myisout = false; datum = 0; /* * Get the next nonnull value in the partition, moving forward or backward - * until we find a value or reach the partition's end. + * until we find a value or reach the partition's end. We cache the + * nullness status because we may repeat this process many times. */ do { - int nn_info; /* NOT NULL info */ + int nn_info; /* NOT NULL status */ abs_pos += forward; - if (abs_pos < 0) /* apparently out of partition */ + if (abs_pos < 0) /* clearly out of partition */ break; /* check NOT NULL cached info */ nn_info = get_notnull_info(winobj, abs_pos); if (nn_info == NN_NOTNULL) /* this row is known to be NOT NULL */ notnull_offset++; - else if (nn_info == NN_NULL) /* this row is known to be NULL */ continue; /* keep on moving forward or backward */ - else /* need to check NULL or not */ { - /* get tupple and evaluate in a partition */ + /* get tuple and evaluate in partition */ datum = gettuple_eval_partition(winobj, argno, abs_pos, isnull, &myisout); if (myisout) /* out of partition? */ @@ -3808,7 +3806,7 @@ WinGetFuncArgInPartition(WindowObject winobj, int argno, } } while (notnull_offset < notnull_relpos); - /* get tupple and evaluate in a partition */ + /* get tuple and evaluate in partition */ datum = gettuple_eval_partition(winobj, argno, abs_pos, isnull, &myisout); if (!myisout && set_mark) |