greenplumn orderedsetaggs 源码
greenplumn orderedsetaggs 代码
文件路径：/src/backend/utils/adt/orderedsetaggs.c
/*-------------------------------------------------------------------------
*
* orderedsetaggs.c
* Ordered-set aggregate functions.
*
* Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/backend/utils/adt/orderedsetaggs.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <math.h>
#include "catalog/pg_aggregate.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_type.h"
#include "executor/executor.h"
#include "miscadmin.h"
#include "nodes/nodeFuncs.h"
#include "optimizer/optimizer.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/timestamp.h"
#include "utils/tuplesort.h"
/*
* Generic support for ordered-set aggregates
*
* The state for an ordered-set aggregate is divided into a per-group struct
* (which is the internal-type transition state datum returned to nodeAgg.c)
* and a per-query struct, which contains data and sub-objects that we can
* create just once per query because they will not change across groups.
* The per-query struct and subsidiary data live in the executor's per-query
* memory context, and go away implicitly at ExecutorEnd().
*
* These structs are set up during the first call of the transition function.
* Because we allow nodeAgg.c to merge ordered-set aggregates (but not
* hypothetical aggregates) with identical inputs and transition functions,
* this info must not depend on the particular aggregate (ie, particular
* final-function), nor on the direct argument(s) of the aggregate.
*/
typedef struct OSAPerQueryState
{
/* Representative Aggref for this aggregate: */
Aggref *aggref;
/* Memory context containing this struct and other per-query data: */
MemoryContext qcontext;
/* Context for expression evaluation */
ExprContext *econtext;
/* Do we expect multiple final-function calls within one group? */
bool rescan_needed;
/* These fields are used only when accumulating tuples: */
/* Tuple descriptor for tuples inserted into sortstate: */
TupleDesc tupdesc;
/* Tuple slot we can use for inserting/extracting tuples: */
TupleTableSlot *tupslot;
/* Per-sort-column sorting information */
int numSortCols;
AttrNumber *sortColIdx;
Oid *sortOperators;
Oid *eqOperators;
Oid *sortCollations;
bool *sortNullsFirsts;
/* Equality operator call info, created only if needed: */
ExprState *compareTuple;
/* These fields are used only when accumulating datums: */
/* Info about datatype of datums being sorted: */
Oid sortColType;
int16 typLen;
bool typByVal;
char typAlign;
/* Info about sort ordering: */
Oid sortOperator;
Oid eqOperator;
Oid sortCollation;
bool sortNullsFirst;
/* Equality operator call info, created only if needed: */
FmgrInfo equalfn;
} OSAPerQueryState;
typedef struct OSAPerGroupState
{
/* Link to the per-query state for this aggregate: */
OSAPerQueryState *qstate;
/* Memory context containing per-group data: */
MemoryContext gcontext;
/* Sort object we're accumulating data in: */
Tuplesortstate *sortstate;
/* Number of normal rows inserted into sortstate: */
int64 number_of_rows;
/* Have we already done tuplesort_performsort? */
bool sort_done;
} OSAPerGroupState;
static void ordered_set_shutdown(Datum arg);
/*
* Set up working state for an ordered-set aggregate
*/
static OSAPerGroupState *
ordered_set_startup(FunctionCallInfo fcinfo, bool use_tuples)
{
OSAPerGroupState *osastate;
OSAPerQueryState *qstate;
MemoryContext gcontext;
MemoryContext oldcontext;
/*
* Check we're called as aggregate (and not a window function), and get
* the Agg node's group-lifespan context (which might change from group to
* group, so we shouldn't cache it in the per-query state).
*/
if (AggCheckCallContext(fcinfo, &gcontext) != AGG_CONTEXT_AGGREGATE)
elog(ERROR, "ordered-set aggregate called in non-aggregate context");
/*
* We keep a link to the per-query state in fn_extra; if it's not there,
* create it, and do the per-query setup we need.
*/
qstate = (OSAPerQueryState *) fcinfo->flinfo->fn_extra;
if (qstate == NULL)
{
Aggref *aggref;
MemoryContext qcontext;
List *sortlist;
int numSortCols;
/* Get the Aggref so we can examine aggregate's arguments */
aggref = AggGetAggref(fcinfo);
if (!aggref)
elog(ERROR, "ordered-set aggregate called in non-aggregate context");
if (!AGGKIND_IS_ORDERED_SET(aggref->aggkind))
elog(ERROR, "ordered-set aggregate support function called for non-ordered-set aggregate");
/*
* Prepare per-query structures in the fn_mcxt, which we assume is the
* executor's per-query context; in any case it's the right place to
* keep anything found via fn_extra.
*/
qcontext = fcinfo->flinfo->fn_mcxt;
oldcontext = MemoryContextSwitchTo(qcontext);
qstate = (OSAPerQueryState *) palloc0(sizeof(OSAPerQueryState));
qstate->aggref = aggref;
qstate->qcontext = qcontext;
/* We need to support rescans if the trans state is shared */
qstate->rescan_needed = AggStateIsShared(fcinfo);
/* Extract the sort information */
sortlist = aggref->aggorder;
numSortCols = list_length(sortlist);
if (use_tuples)
{
bool ishypothetical = (aggref->aggkind == AGGKIND_HYPOTHETICAL);
ListCell *lc;
int i;
if (ishypothetical)
numSortCols++; /* make space for flag column */
qstate->numSortCols = numSortCols;
qstate->sortColIdx = (AttrNumber *) palloc(numSortCols * sizeof(AttrNumber));
qstate->sortOperators = (Oid *) palloc(numSortCols * sizeof(Oid));
qstate->eqOperators = (Oid *) palloc(numSortCols * sizeof(Oid));
qstate->sortCollations = (Oid *) palloc(numSortCols * sizeof(Oid));
qstate->sortNullsFirsts = (bool *) palloc(numSortCols * sizeof(bool));
i = 0;
foreach(lc, sortlist)
{
SortGroupClause *sortcl = (SortGroupClause *) lfirst(lc);
TargetEntry *tle = get_sortgroupclause_tle(sortcl,
aggref->args);
/* the parser should have made sure of this */
Assert(OidIsValid(sortcl->sortop));
qstate->sortColIdx[i] = tle->resno;
qstate->sortOperators[i] = sortcl->sortop;
qstate->eqOperators[i] = sortcl->eqop;
qstate->sortCollations[i] = exprCollation((Node *) tle->expr);
qstate->sortNullsFirsts[i] = sortcl->nulls_first;
i++;
}
if (ishypothetical)
{
/* Add an integer flag column as the last sort column */
qstate->sortColIdx[i] = list_length(aggref->args) + 1;
qstate->sortOperators[i] = Int4LessOperator;
qstate->eqOperators[i] = Int4EqualOperator;
qstate->sortCollations[i] = InvalidOid;
qstate->sortNullsFirsts[i] = false;
i++;
}
Assert(i == numSortCols);
/*
* Get a tupledesc corresponding to the aggregated inputs
* (including sort expressions) of the agg.
*/
qstate->tupdesc = ExecTypeFromTL(aggref->args);
/* If we need a flag column, hack the tupledesc to include that */
if (ishypothetical)
{
TupleDesc newdesc;
int natts = qstate->tupdesc->natts;
newdesc = CreateTemplateTupleDesc(natts + 1);
for (i = 1; i <= natts; i++)
TupleDescCopyEntry(newdesc, i, qstate->tupdesc, i);
TupleDescInitEntry(newdesc,
(AttrNumber) ++natts,
"flag",
INT4OID,
-1,
0);
FreeTupleDesc(qstate->tupdesc);
qstate->tupdesc = newdesc;
}
/* Create slot we'll use to store/retrieve rows */
qstate->tupslot = MakeSingleTupleTableSlot(qstate->tupdesc,
&TTSOpsMinimalTuple);
}
else
{
/* Sort single datums */
SortGroupClause *sortcl;
TargetEntry *tle;
if (numSortCols != 1 || aggref->aggkind == AGGKIND_HYPOTHETICAL)
elog(ERROR, "ordered-set aggregate support function does not support multiple aggregated columns");
sortcl = (SortGroupClause *) linitial(sortlist);
tle = get_sortgroupclause_tle(sortcl, aggref->args);
/* the parser should have made sure of this */
Assert(OidIsValid(sortcl->sortop));
/* Save sort ordering info */
qstate->sortColType = exprType((Node *) tle->expr);
qstate->sortOperator = sortcl->sortop;
qstate->eqOperator = sortcl->eqop;
qstate->sortCollation = exprCollation((Node *) tle->expr);
qstate->sortNullsFirst = sortcl->nulls_first;
/* Save datatype info */
get_typlenbyvalalign(qstate->sortColType,
&qstate->typLen,
&qstate->typByVal,
&qstate->typAlign);
}
fcinfo->flinfo->fn_extra = (void *) qstate;
MemoryContextSwitchTo(oldcontext);
}
/* Now build the stuff we need in group-lifespan context */
oldcontext = MemoryContextSwitchTo(gcontext);
osastate = (OSAPerGroupState *) palloc(sizeof(OSAPerGroupState));
osastate->qstate = qstate;
osastate->gcontext = gcontext;
/*
* Initialize tuplesort object.
*/
if (use_tuples)
osastate->sortstate = tuplesort_begin_heap(qstate->tupdesc,
qstate->numSortCols,
qstate->sortColIdx,
qstate->sortOperators,
qstate->sortCollations,
qstate->sortNullsFirsts,
work_mem,
NULL,
qstate->rescan_needed);
else
osastate->sortstate = tuplesort_begin_datum(qstate->sortColType,
qstate->sortOperator,
qstate->sortCollation,
qstate->sortNullsFirst,
work_mem,
NULL,
qstate->rescan_needed);
osastate->number_of_rows = 0;
osastate->sort_done = false;
/* Now register a shutdown callback to clean things up at end of group */
AggRegisterCallback(fcinfo,
ordered_set_shutdown,
PointerGetDatum(osastate));
MemoryContextSwitchTo(oldcontext);
return osastate;
}
/*
* Clean up when evaluation of an ordered-set aggregate is complete.
*
* We don't need to bother freeing objects in the per-group memory context,
* since that will get reset anyway by nodeAgg.c; nor should we free anything
* in the per-query context, which will get cleared (if this was the last
* group) by ExecutorEnd. But we must take care to release any potential
* non-memory resources.
*
* In the case where we're not expecting multiple finalfn calls, we could
* arguably rely on the finalfn to clean up; but it's easier and more testable
* if we just do it the same way in either case.
*/
static void
ordered_set_shutdown(Datum arg)
{
OSAPerGroupState *osastate = (OSAPerGroupState *) DatumGetPointer(arg);
/* Tuplesort object might have temp files. */
if (osastate->sortstate)
tuplesort_end(osastate->sortstate);
osastate->sortstate = NULL;
/* The tupleslot probably can't be holding a pin, but let's be safe. */
if (osastate->qstate->tupslot)
ExecClearTuple(osastate->qstate->tupslot);
}
/*
* Generic transition function for ordered-set aggregates
* with a single input column in which we want to suppress nulls
*/
Datum
ordered_set_transition(PG_FUNCTION_ARGS)
{
OSAPerGroupState *osastate;
/* If first call, create the transition state workspace */
if (PG_ARGISNULL(0))
osastate = ordered_set_startup(fcinfo, false);
else
osastate = (OSAPerGroupState *) PG_GETARG_POINTER(0);
/* Load the datum into the tuplesort object, but only if it's not null */
if (!PG_ARGISNULL(1))
{
tuplesort_putdatum(osastate->sortstate, PG_GETARG_DATUM(1), false);
osastate->number_of_rows++;
}
PG_RETURN_POINTER(osastate);
}
/*
* Generic transition function for ordered-set aggregates
* with (potentially) multiple aggregated input columns
*/
Datum
ordered_set_transition_multi(PG_FUNCTION_ARGS)
{
OSAPerGroupState *osastate;
TupleTableSlot *slot;
int nargs;
int i;
/* If first call, create the transition state workspace */
if (PG_ARGISNULL(0))
osastate = ordered_set_startup(fcinfo, true);
else
osastate = (OSAPerGroupState *) PG_GETARG_POINTER(0);
/* Form a tuple from all the other inputs besides the transition value */
slot = osastate->qstate->tupslot;
ExecClearTuple(slot);
nargs = PG_NARGS() - 1;
for (i = 0; i < nargs; i++)
{
slot->tts_values[i] = PG_GETARG_DATUM(i + 1);
slot->tts_isnull[i] = PG_ARGISNULL(i + 1);
}
if (osastate->qstate->aggref->aggkind == AGGKIND_HYPOTHETICAL)
{
/* Add a zero flag value to mark this row as a normal input row */
slot->tts_values[i] = Int32GetDatum(0);
slot->tts_isnull[i] = false;
i++;
}
Assert(i == slot->tts_tupleDescriptor->natts);
ExecStoreVirtualTuple(slot);
/* Load the row into the tuplesort object */
tuplesort_puttupleslot(osastate->sortstate, slot);
osastate->number_of_rows++;
PG_RETURN_POINTER(osastate);
}
/*
* percentile_disc(float8) within group(anyelement) - discrete percentile
*/
Datum
percentile_disc_final(PG_FUNCTION_ARGS)
{
OSAPerGroupState *osastate;
double percentile;
Datum val;
bool isnull;
int64 rownum;
Assert(AggCheckCallContext(fcinfo, NULL) == AGG_CONTEXT_AGGREGATE);
/* Get and check the percentile argument */
if (PG_ARGISNULL(1))
PG_RETURN_NULL();
percentile = PG_GETARG_FLOAT8(1);
if (percentile < 0 || percentile > 1 || isnan(percentile))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("percentile value %g is not between 0 and 1",
percentile)));
/* If there were no regular rows, the result is NULL */
if (PG_ARGISNULL(0))
PG_RETURN_NULL();
osastate = (OSAPerGroupState *) PG_GETARG_POINTER(0);
/* number_of_rows could be zero if we only saw NULL input values */
if (osastate->number_of_rows == 0)
PG_RETURN_NULL();
/* Finish the sort, or rescan if we already did */
if (!osastate->sort_done)
{
tuplesort_performsort(osastate->sortstate);
osastate->sort_done = true;
}
else
tuplesort_rescan(osastate->sortstate);
/*----------
* We need the smallest K such that (K/N) >= percentile.
* N>0, therefore K >= N*percentile, therefore K = ceil(N*percentile).
* So we skip K-1 rows (if K>0) and return the next row fetched.
*----------
*/
rownum = (int64) ceil(percentile * osastate->number_of_rows);
Assert(rownum <= osastate->number_of_rows);
if (rownum > 1)
{
if (!tuplesort_skiptuples(osastate->sortstate, rownum - 1, true))
elog(ERROR, "missing row in percentile_disc");
}
if (!tuplesort_getdatum(osastate->sortstate, true, &val, &isnull, NULL))
elog(ERROR, "missing row in percentile_disc");
/* We shouldn't have stored any nulls, but do the right thing anyway */
if (isnull)
PG_RETURN_NULL();
else
PG_RETURN_DATUM(val);
}
/*
* For percentile_cont, we need a way to interpolate between consecutive
* values. Use a helper function for that, so that we can share the rest
* of the code between types.
*/
typedef Datum (*LerpFunc) (Datum lo, Datum hi, double pct);
static Datum
float8_lerp(Datum lo, Datum hi, double pct)
{
double loval = DatumGetFloat8(lo);
double hival = DatumGetFloat8(hi);
return Float8GetDatum(loval + (pct * (hival - loval)));
}
static Datum
interval_lerp(Datum lo, Datum hi, double pct)
{
Datum diff_result = DirectFunctionCall2(interval_mi, hi, lo);
Datum mul_result = DirectFunctionCall2(interval_mul,
diff_result,
Float8GetDatumFast(pct));
return DirectFunctionCall2(interval_pl, mul_result, lo);
}
static Datum
timestamp_lerp(Datum lo, Datum hi, double pct)
{
Timestamp lots = DatumGetTimestamp(lo);
Timestamp hits = DatumGetTimestamp(hi);
Timestamp diff_result;
Timestamp mul_result;
diff_result = hits - lots;
#ifdef HAVE_INT64_TIMESTAMP
mul_result = (Timestamp) round(diff_result * pct);
#else
mul_result = (Timestamp) diff_result * pct;
#endif
return TimestampGetDatum(lo + mul_result);
}
static Datum
timestamptz_lerp(Datum lo, Datum hi, double pct)
{
TimestampTz lots = DatumGetTimestampTz(lo);
TimestampTz hits = DatumGetTimestampTz(hi);
TimestampTz diff_result;
TimestampTz mul_result;
diff_result = hits - lots;
#ifdef HAVE_INT64_TIMESTAMP
mul_result = (TimestampTz) round(diff_result * pct);
#else
mul_result = (TimestampTz) diff_result * pct;
#endif
return TimestampTzGetDatum(lo + mul_result);
}
/*
* Continuous percentile
*/
static Datum
percentile_cont_final_common(FunctionCallInfo fcinfo,
Oid expect_type,
LerpFunc lerpfunc)
{
OSAPerGroupState *osastate;
double percentile;
int64 first_row = 0;
int64 second_row = 0;
Datum val;
Datum first_val;
Datum second_val;
double proportion;
bool isnull;
Assert(AggCheckCallContext(fcinfo, NULL) == AGG_CONTEXT_AGGREGATE);
/* Get and check the percentile argument */
if (PG_ARGISNULL(1))
PG_RETURN_NULL();
percentile = PG_GETARG_FLOAT8(1);
if (percentile < 0 || percentile > 1 || isnan(percentile))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("percentile value %g is not between 0 and 1",
percentile)));
/* If there were no regular rows, the result is NULL */
if (PG_ARGISNULL(0))
PG_RETURN_NULL();
osastate = (OSAPerGroupState *) PG_GETARG_POINTER(0);
/* number_of_rows could be zero if we only saw NULL input values */
if (osastate->number_of_rows == 0)
PG_RETURN_NULL();
Assert(expect_type == osastate->qstate->sortColType);
/* Finish the sort, or rescan if we already did */
if (!osastate->sort_done)
{
tuplesort_performsort(osastate->sortstate);
osastate->sort_done = true;
}
else
tuplesort_rescan(osastate->sortstate);
first_row = floor(percentile * (osastate->number_of_rows - 1));
second_row = ceil(percentile * (osastate->number_of_rows - 1));
Assert(first_row < osastate->number_of_rows);
if (!tuplesort_skiptuples(osastate->sortstate, first_row, true))
elog(ERROR, "missing row in percentile_cont");
if (!tuplesort_getdatum(osastate->sortstate, true, &first_val, &isnull, NULL))
elog(ERROR, "missing row in percentile_cont");
if (isnull)
PG_RETURN_NULL();
if (first_row == second_row)
{
val = first_val;
}
else
{
if (!tuplesort_getdatum(osastate->sortstate, true, &second_val, &isnull, NULL))
elog(ERROR, "missing row in percentile_cont");
if (isnull)
PG_RETURN_NULL();
proportion = (percentile * (osastate->number_of_rows - 1)) - first_row;
val = lerpfunc(first_val, second_val, proportion);
}
PG_RETURN_DATUM(val);
}
/*
* percentile_cont(float8) within group (float8) - continuous percentile
*/
Datum
percentile_cont_float8_final(PG_FUNCTION_ARGS)
{
return percentile_cont_final_common(fcinfo, FLOAT8OID, float8_lerp);
}
/*
* percentile_cont(float8) within group (interval) - continuous percentile
*/
Datum
percentile_cont_interval_final(PG_FUNCTION_ARGS)
{
return percentile_cont_final_common(fcinfo, INTERVALOID, interval_lerp);
}
/*
* percentile_cont(float8) within group (timestamp) - continuous percentile
*/
Datum
percentile_cont_timestamp_final(PG_FUNCTION_ARGS)
{
return percentile_cont_final_common(fcinfo, TIMESTAMPOID, timestamp_lerp);
}
/*
* percentile_cont(float8) within group (timestamptz) - continuous percentile
*/
Datum
percentile_cont_timestamptz_final(PG_FUNCTION_ARGS)
{
return percentile_cont_final_common(fcinfo, TIMESTAMPTZOID, timestamptz_lerp);
}
/*
* Support code for handling arrays of percentiles
*
* Note: in each pct_info entry, second_row should be equal to or
* exactly one more than first_row.
*/
struct pct_info
{
int64 first_row; /* first row to sample */
int64 second_row; /* possible second row to sample */
double proportion; /* interpolation fraction */
int idx; /* index of this item in original array */
};
/*
* Sort comparator to sort pct_infos by first_row then second_row
*/
static int
pct_info_cmp(const void *pa, const void *pb)
{
const struct pct_info *a = (const struct pct_info *) pa;
const struct pct_info *b = (const struct pct_info *) pb;
if (a->first_row != b->first_row)
return (a->first_row < b->first_row) ? -1 : 1;
if (a->second_row != b->second_row)
return (a->second_row < b->second_row) ? -1 : 1;
return 0;
}
/*
* Construct array showing which rows to sample for percentiles.
*/
static struct pct_info *
setup_pct_info(int num_percentiles,
Datum *percentiles_datum,
bool *percentiles_null,
int64 rowcount,
bool continuous)
{
struct pct_info *pct_info;
int i;
pct_info = (struct pct_info *) palloc(num_percentiles * sizeof(struct pct_info));
for (i = 0; i < num_percentiles; i++)
{
pct_info[i].idx = i;
if (percentiles_null[i])
{
/* dummy entry for any NULL in array */
pct_info[i].first_row = 0;
pct_info[i].second_row = 0;
pct_info[i].proportion = 0;
}
else
{
double p = DatumGetFloat8(percentiles_datum[i]);
if (p < 0 || p > 1 || isnan(p))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("percentile value %g is not between 0 and 1",
p)));
if (continuous)
{
pct_info[i].first_row = 1 + floor(p * (rowcount - 1));
pct_info[i].second_row = 1 + ceil(p * (rowcount - 1));
pct_info[i].proportion = (p * (rowcount - 1)) - floor(p * (rowcount - 1));
}
else
{
/*----------
* We need the smallest K such that (K/N) >= percentile.
* N>0, therefore K >= N*percentile, therefore
* K = ceil(N*percentile); but not less than 1.
*----------
*/
int64 row = (int64) ceil(p * rowcount);
row = Max(1, row);
pct_info[i].first_row = row;
pct_info[i].second_row = row;
pct_info[i].proportion = 0;
}
}
}
/*
* The parameter array wasn't necessarily in sorted order, but we need to
* visit the rows in order, so sort by first_row/second_row.
*/
qsort(pct_info, num_percentiles, sizeof(struct pct_info), pct_info_cmp);
return pct_info;
}
/*
* percentile_disc(float8[]) within group (anyelement) - discrete percentiles
*/
Datum
percentile_disc_multi_final(PG_FUNCTION_ARGS)
{
OSAPerGroupState *osastate;
ArrayType *param;
Datum *percentiles_datum;
bool *percentiles_null;
int num_percentiles;
struct pct_info *pct_info;
Datum *result_datum;
bool *result_isnull;
int64 rownum = 0;
Datum val = (Datum) 0;
bool isnull = true;
int i;
Assert(AggCheckCallContext(fcinfo, NULL) == AGG_CONTEXT_AGGREGATE);
/* If there were no regular rows, the result is NULL */
if (PG_ARGISNULL(0))
PG_RETURN_NULL();
osastate = (OSAPerGroupState *) PG_GETARG_POINTER(0);
/* number_of_rows could be zero if we only saw NULL input values */
if (osastate->number_of_rows == 0)
PG_RETURN_NULL();
/* Deconstruct the percentile-array input */
if (PG_ARGISNULL(1))
PG_RETURN_NULL();
param = PG_GETARG_ARRAYTYPE_P(1);
deconstruct_array(param, FLOAT8OID,
/* hard-wired info on type float8 */
8, FLOAT8PASSBYVAL, 'd',
&percentiles_datum,
&percentiles_null,
&num_percentiles);
if (num_percentiles == 0)
PG_RETURN_POINTER(construct_empty_array(osastate->qstate->sortColType));
pct_info = setup_pct_info(num_percentiles,
percentiles_datum,
percentiles_null,
osastate->number_of_rows,
false);
result_datum = (Datum *) palloc(num_percentiles * sizeof(Datum));
result_isnull = (bool *) palloc(num_percentiles * sizeof(bool));
/*
* Start by dealing with any nulls in the param array - those are sorted
* to the front on row=0, so set the corresponding result indexes to null
*/
for (i = 0; i < num_percentiles; i++)
{
int idx = pct_info[i].idx;
if (pct_info[i].first_row > 0)
break;
result_datum[idx] = (Datum) 0;
result_isnull[idx] = true;
}
/*
* If there's anything left after doing the nulls, then grind the input
* and extract the needed values
*/
if (i < num_percentiles)
{
/* Finish the sort, or rescan if we already did */
if (!osastate->sort_done)
{
tuplesort_performsort(osastate->sortstate);
osastate->sort_done = true;
}
else
tuplesort_rescan(osastate->sortstate);
for (; i < num_percentiles; i++)
{
int64 target_row = pct_info[i].first_row;
int idx = pct_info[i].idx;
/* Advance to target row, if not already there */
if (target_row > rownum)
{
if (!tuplesort_skiptuples(osastate->sortstate, target_row - rownum - 1, true))
elog(ERROR, "missing row in percentile_disc");
if (!tuplesort_getdatum(osastate->sortstate, true, &val, &isnull, NULL))
elog(ERROR, "missing row in percentile_disc");
rownum = target_row;
}
result_datum[idx] = val;
result_isnull[idx] = isnull;
}
}
/* We make the output array the same shape as the input */
PG_RETURN_POINTER(construct_md_array(result_datum, result_isnull,
ARR_NDIM(param),
ARR_DIMS(param),
ARR_LBOUND(param),
osastate->qstate->sortColType,
osastate->qstate->typLen,
osastate->qstate->typByVal,
osastate->qstate->typAlign));
}
/*
* percentile_cont(float8[]) within group () - continuous percentiles
*/
static Datum
percentile_cont_multi_final_common(FunctionCallInfo fcinfo,
Oid expect_type,
int16 typLen, bool typByVal, char typAlign,
LerpFunc lerpfunc)
{
OSAPerGroupState *osastate;
ArrayType *param;
Datum *percentiles_datum;
bool *percentiles_null;
int num_percentiles;
struct pct_info *pct_info;
Datum *result_datum;
bool *result_isnull;
int64 rownum = 0;
Datum first_val = (Datum) 0;
Datum second_val = (Datum) 0;
bool isnull;
int i;
Assert(AggCheckCallContext(fcinfo, NULL) == AGG_CONTEXT_AGGREGATE);
/* If there were no regular rows, the result is NULL */
if (PG_ARGISNULL(0))
PG_RETURN_NULL();
osastate = (OSAPerGroupState *) PG_GETARG_POINTER(0);
/* number_of_rows could be zero if we only saw NULL input values */
if (osastate->number_of_rows == 0)
PG_RETURN_NULL();
Assert(expect_type == osastate->qstate->sortColType);
/* Deconstruct the percentile-array input */
if (PG_ARGISNULL(1))
PG_RETURN_NULL();
param = PG_GETARG_ARRAYTYPE_P(1);
deconstruct_array(param, FLOAT8OID,
/* hard-wired info on type float8 */
8, FLOAT8PASSBYVAL, 'd',
&percentiles_datum,
&percentiles_null,
&num_percentiles);
if (num_percentiles == 0)
PG_RETURN_POINTER(construct_empty_array(osastate->qstate->sortColType));
pct_info = setup_pct_info(num_percentiles,
percentiles_datum,
percentiles_null,
osastate->number_of_rows,
true);
result_datum = (Datum *) palloc(num_percentiles * sizeof(Datum));
result_isnull = (bool *) palloc(num_percentiles * sizeof(bool));
/*
* Start by dealing with any nulls in the param array - those are sorted
* to the front on row=0, so set the corresponding result indexes to null
*/
for (i = 0; i < num_percentiles; i++)
{
int idx = pct_info[i].idx;
if (pct_info[i].first_row > 0)
break;
result_datum[idx] = (Datum) 0;
result_isnull[idx] = true;
}
/*
* If there's anything left after doing the nulls, then grind the input
* and extract the needed values
*/
if (i < num_percentiles)
{
/* Finish the sort, or rescan if we already did */
if (!osastate->sort_done)
{
tuplesort_performsort(osastate->sortstate);
osastate->sort_done = true;
}
else
tuplesort_rescan(osastate->sortstate);
for (; i < num_percentiles; i++)
{
int64 first_row = pct_info[i].first_row;
int64 second_row = pct_info[i].second_row;
int idx = pct_info[i].idx;
/*
* Advance to first_row, if not already there. Note that we might
* already have rownum beyond first_row, in which case first_val
* is already correct. (This occurs when interpolating between
* the same two input rows as for the previous percentile.)
*/
if (first_row > rownum)
{
if (!tuplesort_skiptuples(osastate->sortstate, first_row - rownum - 1, true))
elog(ERROR, "missing row in percentile_cont");
if (!tuplesort_getdatum(osastate->sortstate, true, &first_val,
&isnull, NULL) || isnull)
elog(ERROR, "missing row in percentile_cont");
rownum = first_row;
/* Always advance second_val to be latest input value */
second_val = first_val;
}
else if (first_row == rownum)
{
/*
* We are already at the desired row, so we must previously
* have read its value into second_val (and perhaps first_val
* as well, but this assignment is harmless in that case).
*/
first_val = second_val;
}
/* Fetch second_row if needed */
if (second_row > rownum)
{
if (!tuplesort_getdatum(osastate->sortstate, true, &second_val,
&isnull, NULL) || isnull)
elog(ERROR, "missing row in percentile_cont");
rownum++;
}
/* We should now certainly be on second_row exactly */
Assert(second_row == rownum);
/* Compute appropriate result */
if (second_row > first_row)
result_datum[idx] = lerpfunc(first_val, second_val,
pct_info[i].proportion);
else
result_datum[idx] = first_val;
result_isnull[idx] = false;
}
}
/* We make the output array the same shape as the input */
PG_RETURN_POINTER(construct_md_array(result_datum, result_isnull,
ARR_NDIM(param),
ARR_DIMS(param), ARR_LBOUND(param),
expect_type,
typLen,
typByVal,
typAlign));
}
/*
* percentile_cont(float8[]) within group (float8) - continuous percentiles
*/
Datum
percentile_cont_float8_multi_final(PG_FUNCTION_ARGS)
{
return percentile_cont_multi_final_common(fcinfo,
FLOAT8OID,
/* hard-wired info on type float8 */
8, FLOAT8PASSBYVAL, 'd',
float8_lerp);
}
/*
* percentile_cont(float8[]) within group (interval) - continuous percentiles
*/
Datum
percentile_cont_interval_multi_final(PG_FUNCTION_ARGS)
{
return percentile_cont_multi_final_common(fcinfo,
INTERVALOID,
/* hard-wired info on type interval */
16, false, 'd',
interval_lerp);
}
/*
* percentile_cont(float8[]) within group (timestamp) - continuous percentiles
*/
Datum
percentile_cont_timestamp_multi_final(PG_FUNCTION_ARGS)
{
return percentile_cont_multi_final_common(fcinfo,
TIMESTAMPOID,
/* hard-wired info on type interval */
8, FLOAT8PASSBYVAL, 'd',
timestamp_lerp);
}
/*
* percentile_cont(float8[]) within group (timestamptz) - continuous percentiles
*/
Datum
percentile_cont_timestamptz_multi_final(PG_FUNCTION_ARGS)
{
return percentile_cont_multi_final_common(fcinfo,
TIMESTAMPTZOID,
/* hard-wired info on type interval */
8, FLOAT8PASSBYVAL, 'd',
timestamptz_lerp);
}
/*
* mode() within group (anyelement) - most common value
*/
Datum
mode_final(PG_FUNCTION_ARGS)
{
OSAPerGroupState *osastate;
Datum val;
bool isnull;
Datum mode_val = (Datum) 0;
int64 mode_freq = 0;
Datum last_val = (Datum) 0;
int64 last_val_freq = 0;
bool last_val_is_mode = false;
FmgrInfo *equalfn;
Datum abbrev_val = (Datum) 0;
Datum last_abbrev_val = (Datum) 0;
bool shouldfree;
Assert(AggCheckCallContext(fcinfo, NULL) == AGG_CONTEXT_AGGREGATE);
/* If there were no regular rows, the result is NULL */
if (PG_ARGISNULL(0))
PG_RETURN_NULL();
osastate = (OSAPerGroupState *) PG_GETARG_POINTER(0);
/* number_of_rows could be zero if we only saw NULL input values */
if (osastate->number_of_rows == 0)
PG_RETURN_NULL();
/* Look up the equality function for the datatype, if we didn't already */
equalfn = &(osastate->qstate->equalfn);
if (!OidIsValid(equalfn->fn_oid))
fmgr_info_cxt(get_opcode(osastate->qstate->eqOperator), equalfn,
osastate->qstate->qcontext);
shouldfree = !(osastate->qstate->typByVal);
/* Finish the sort, or rescan if we already did */
if (!osastate->sort_done)
{
tuplesort_performsort(osastate->sortstate);
osastate->sort_done = true;
}
else
tuplesort_rescan(osastate->sortstate);
/* Scan tuples and count frequencies */
while (tuplesort_getdatum(osastate->sortstate, true, &val, &isnull, &abbrev_val))
{
/* we don't expect any nulls, but ignore them if found */
if (isnull)
continue;
if (last_val_freq == 0)
{
/* first nonnull value - it's the mode for now */
mode_val = last_val = val;
mode_freq = last_val_freq = 1;
last_val_is_mode = true;
last_abbrev_val = abbrev_val;
}
else if (abbrev_val == last_abbrev_val &&
DatumGetBool(FunctionCall2Coll(equalfn, PG_GET_COLLATION(), val, last_val)))
{
/* value equal to previous value, count it */
if (last_val_is_mode)
mode_freq++; /* needn't maintain last_val_freq */
else if (++last_val_freq > mode_freq)
{
/* last_val becomes new mode */
if (shouldfree)
pfree(DatumGetPointer(mode_val));
mode_val = last_val;
mode_freq = last_val_freq;
last_val_is_mode = true;
}
if (shouldfree)
pfree(DatumGetPointer(val));
}
else
{
/* val should replace last_val */
if (shouldfree && !last_val_is_mode)
pfree(DatumGetPointer(last_val));
last_val = val;
/* avoid equality function calls by reusing abbreviated keys */
last_abbrev_val = abbrev_val;
last_val_freq = 1;
last_val_is_mode = false;
}
CHECK_FOR_INTERRUPTS();
}
if (shouldfree && !last_val_is_mode)
pfree(DatumGetPointer(last_val));
if (mode_freq)
PG_RETURN_DATUM(mode_val);
else
PG_RETURN_NULL();
}
/*
* Common code to sanity-check args for hypothetical-set functions. No need
* for friendly errors, these can only happen if someone's messing up the
* aggregate definitions. The checks are needed for security, however.
*/
static void
hypothetical_check_argtypes(FunctionCallInfo fcinfo, int nargs,
TupleDesc tupdesc)
{
int i;
/* check that we have an int4 flag column */
if (!tupdesc ||
(nargs + 1) != tupdesc->natts ||
TupleDescAttr(tupdesc, nargs)->atttypid != INT4OID)
elog(ERROR, "type mismatch in hypothetical-set function");
/* check that direct args match in type with aggregated args */
for (i = 0; i < nargs; i++)
{
Form_pg_attribute attr = TupleDescAttr(tupdesc, i);
if (get_fn_expr_argtype(fcinfo->flinfo, i + 1) != attr->atttypid)
elog(ERROR, "type mismatch in hypothetical-set function");
}
}
/*
* compute rank of hypothetical row
*
* flag should be -1 to sort hypothetical row ahead of its peers, or +1
* to sort behind.
* total number of regular rows is returned into *number_of_rows.
*/
static int64
hypothetical_rank_common(FunctionCallInfo fcinfo, int flag,
int64 *number_of_rows)
{
int nargs = PG_NARGS() - 1;
int64 rank = 1;
OSAPerGroupState *osastate;
TupleTableSlot *slot;
int i;
Assert(AggCheckCallContext(fcinfo, NULL) == AGG_CONTEXT_AGGREGATE);
/* If there were no regular rows, the rank is always 1 */
if (PG_ARGISNULL(0))
{
*number_of_rows = 0;
return 1;
}
osastate = (OSAPerGroupState *) PG_GETARG_POINTER(0);
*number_of_rows = osastate->number_of_rows;
/* Adjust nargs to be the number of direct (or aggregated) args */
if (nargs % 2 != 0)
elog(ERROR, "wrong number of arguments in hypothetical-set function");
nargs /= 2;
hypothetical_check_argtypes(fcinfo, nargs, osastate->qstate->tupdesc);
/* because we need a hypothetical row, we can't share transition state */
Assert(!osastate->sort_done);
/* insert the hypothetical row into the sort */
slot = osastate->qstate->tupslot;
ExecClearTuple(slot);
for (i = 0; i < nargs; i++)
{
slot->tts_values[i] = PG_GETARG_DATUM(i + 1);
slot->tts_isnull[i] = PG_ARGISNULL(i + 1);
}
slot->tts_values[i] = Int32GetDatum(flag);
slot->tts_isnull[i] = false;
ExecStoreVirtualTuple(slot);
tuplesort_puttupleslot(osastate->sortstate, slot);
/* finish the sort */
tuplesort_performsort(osastate->sortstate);
osastate->sort_done = true;
/* iterate till we find the hypothetical row */
while (tuplesort_gettupleslot(osastate->sortstate, true, true, slot, NULL))
{
bool isnull;
Datum d = slot_getattr(slot, nargs + 1, &isnull);
if (!isnull && DatumGetInt32(d) != 0)
break;
rank++;
CHECK_FOR_INTERRUPTS();
}
ExecClearTuple(slot);
return rank;
}
/*
* rank() - rank of hypothetical row
*/
Datum
hypothetical_rank_final(PG_FUNCTION_ARGS)
{
int64 rank;
int64 rowcount;
rank = hypothetical_rank_common(fcinfo, -1, &rowcount);
PG_RETURN_INT64(rank);
}
/*
* percent_rank() - percentile rank of hypothetical row
*/
Datum
hypothetical_percent_rank_final(PG_FUNCTION_ARGS)
{
int64 rank;
int64 rowcount;
double result_val;
rank = hypothetical_rank_common(fcinfo, -1, &rowcount);
if (rowcount == 0)
PG_RETURN_FLOAT8(0);
result_val = (double) (rank - 1) / (double) (rowcount);
PG_RETURN_FLOAT8(result_val);
}
/*
* cume_dist() - cumulative distribution of hypothetical row
*/
Datum
hypothetical_cume_dist_final(PG_FUNCTION_ARGS)
{
int64 rank;
int64 rowcount;
double result_val;
rank = hypothetical_rank_common(fcinfo, 1, &rowcount);
result_val = (double) (rank) / (double) (rowcount + 1);
PG_RETURN_FLOAT8(result_val);
}
/*
* dense_rank() - rank of hypothetical row without gaps in ranking
*/
Datum
hypothetical_dense_rank_final(PG_FUNCTION_ARGS)
{
ExprContext *econtext;
ExprState *compareTuple;
int nargs = PG_NARGS() - 1;
int64 rank = 1;
int64 duplicate_count = 0;
OSAPerGroupState *osastate;
int numDistinctCols;
Datum abbrevVal = (Datum) 0;
Datum abbrevOld = (Datum) 0;
TupleTableSlot *slot;
TupleTableSlot *extraslot;
TupleTableSlot *slot2;
int i;
Assert(AggCheckCallContext(fcinfo, NULL) == AGG_CONTEXT_AGGREGATE);
/* If there were no regular rows, the rank is always 1 */
if (PG_ARGISNULL(0))
PG_RETURN_INT64(rank);
osastate = (OSAPerGroupState *) PG_GETARG_POINTER(0);
econtext = osastate->qstate->econtext;
if (!econtext)
{
MemoryContext oldcontext;
/* Make sure to we create econtext under correct parent context. */
oldcontext = MemoryContextSwitchTo(osastate->qstate->qcontext);
osastate->qstate->econtext = CreateStandaloneExprContext();
econtext = osastate->qstate->econtext;
MemoryContextSwitchTo(oldcontext);
}
/* Adjust nargs to be the number of direct (or aggregated) args */
if (nargs % 2 != 0)
elog(ERROR, "wrong number of arguments in hypothetical-set function");
nargs /= 2;
hypothetical_check_argtypes(fcinfo, nargs, osastate->qstate->tupdesc);
/*
* When comparing tuples, we can omit the flag column since we will only
* compare rows with flag == 0.
*/
numDistinctCols = osastate->qstate->numSortCols - 1;
/* Build tuple comparator, if we didn't already */
compareTuple = osastate->qstate->compareTuple;
if (compareTuple == NULL)
{
AttrNumber *sortColIdx = osastate->qstate->sortColIdx;
MemoryContext oldContext;
oldContext = MemoryContextSwitchTo(osastate->qstate->qcontext);
compareTuple = execTuplesMatchPrepare(osastate->qstate->tupdesc,
numDistinctCols,
sortColIdx,
osastate->qstate->eqOperators,
osastate->qstate->sortCollations,
NULL);
MemoryContextSwitchTo(oldContext);
osastate->qstate->compareTuple = compareTuple;
}
/* because we need a hypothetical row, we can't share transition state */
Assert(!osastate->sort_done);
/* insert the hypothetical row into the sort */
slot = osastate->qstate->tupslot;
ExecClearTuple(slot);
for (i = 0; i < nargs; i++)
{
slot->tts_values[i] = PG_GETARG_DATUM(i + 1);
slot->tts_isnull[i] = PG_ARGISNULL(i + 1);
}
slot->tts_values[i] = Int32GetDatum(-1);
slot->tts_isnull[i] = false;
ExecStoreVirtualTuple(slot);
tuplesort_puttupleslot(osastate->sortstate, slot);
/* finish the sort */
tuplesort_performsort(osastate->sortstate);
osastate->sort_done = true;
/*
* We alternate fetching into tupslot and extraslot so that we have the
* previous row available for comparisons. This is accomplished by
* swapping the slot pointer variables after each row.
*/
extraslot = MakeSingleTupleTableSlot(osastate->qstate->tupdesc,
&TTSOpsMinimalTuple);
slot2 = extraslot;
/* iterate till we find the hypothetical row */
while (tuplesort_gettupleslot(osastate->sortstate, true, true, slot,
&abbrevVal))
{
bool isnull;
Datum d = slot_getattr(slot, nargs + 1, &isnull);
TupleTableSlot *tmpslot;
if (!isnull && DatumGetInt32(d) != 0)
break;
/* count non-distinct tuples */
econtext->ecxt_outertuple = slot;
econtext->ecxt_innertuple = slot2;
if (!TupIsNull(slot2) &&
abbrevVal == abbrevOld &&
ExecQualAndReset(compareTuple, econtext))
duplicate_count++;
tmpslot = slot2;
slot2 = slot;
slot = tmpslot;
/* avoid ExecQual() calls by reusing abbreviated keys */
abbrevOld = abbrevVal;
rank++;
CHECK_FOR_INTERRUPTS();
}
ExecClearTuple(slot);
ExecClearTuple(slot2);
ExecDropSingleTupleTableSlot(extraslot);
rank = rank - duplicate_count;
PG_RETURN_INT64(rank);
}
/*
* Generic transition function for gp_percentile_cont
* with a single input column in which we want to suppress nulls
* This assumes the input tuples are already sorted
*/
static Datum
gp_percentile_cont_transition(FunctionCallInfo fcinfo,
LerpFunc lerpfunc)
{
int64 first_row;
int64 second_row;
/* Ignore NULL inputs for val, percent and total_count*/
if (PG_ARGISNULL(1) || PG_ARGISNULL(2) || PG_ARGISNULL(3))
PG_RETURN_NULL();
double percentile = PG_GETARG_FLOAT8(2);
if (percentile < 0 || percentile > 1 || isnan(percentile))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("percentile value %g is not between 0 and 1",
percentile)));
Datum prev_state = PG_GETARG_DATUM(0);
Datum val = PG_GETARG_DATUM(1);
Datum return_state = prev_state;
int64 total_rows = PG_GETARG_INT64(3);
first_row = (int64) floor(percentile * (total_rows - 1));
second_row = (int64) ceil(percentile * (total_rows - 1));
double proportion = (percentile * (total_rows - 1)) - floor(percentile * (total_rows - 1));
int64 *cnt;
if(first_row == second_row)
proportion = 0;
if (!fcinfo->flinfo->fn_extra)
{
cnt = (int64 *) MemoryContextAllocZero(fcinfo->flinfo->fn_mcxt, sizeof(int64));
*cnt = 1;
fcinfo->flinfo->fn_extra = cnt;
}
else
{
cnt = (int64 *) fcinfo->flinfo->fn_extra;
}
if(*cnt == first_row)
{
return_state = val;
}
else if(*cnt == second_row)
{
return_state = lerpfunc(prev_state, val, proportion);
}
*cnt = *cnt + 1;
if(*cnt >= total_rows)
{
/* Clean up, so the next group can see NULL for fn_extra */
pfree(cnt);
fcinfo->flinfo->fn_extra = NULL;
}
PG_RETURN_DATUM(return_state);
}
/*
* gp_percentile_cont(float8, float8, bigint) - continuous percentile
*/
Datum
gp_percentile_cont_float8_transition(PG_FUNCTION_ARGS)
{
return gp_percentile_cont_transition(fcinfo, float8_lerp);
}
/*
* gp_percentile_cont(interval, float8, bigint) - continuous percentile
*/
Datum
gp_percentile_cont_interval_transition(PG_FUNCTION_ARGS)
{
return gp_percentile_cont_transition(fcinfo, interval_lerp);
}
/*
* gp_percentile_cont(timestamp, float8, bigint) - continuous percentile
*/
Datum
gp_percentile_cont_timestamp_transition(PG_FUNCTION_ARGS)
{
return gp_percentile_cont_transition(fcinfo, timestamp_lerp);
}
/*
* gp_percentile_cont(timestamptz, float8, bigint) - continuous percentile
*/
Datum
gp_percentile_cont_timestamptz_transition(PG_FUNCTION_ARGS)
{
return gp_percentile_cont_transition(fcinfo, timestamptz_lerp);
}
/*
* Transition function for gp_percentile_disc - discrete percentile
* This assumes the input tuples are already sorted
*/
Datum
gp_percentile_disc_transition(PG_FUNCTION_ARGS)
{
int64 rownum;
/* Ignore NULL inputs for val, percent and total_count*/
if (PG_ARGISNULL(1) || PG_ARGISNULL(2) || PG_ARGISNULL(3))
PG_RETURN_NULL();
double percentile = PG_GETARG_FLOAT8(2);
if (percentile < 0 || percentile > 1 || isnan(percentile))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("percentile value %g is not between 0 and 1",
percentile)));
Datum prev_state = PG_GETARG_DATUM(0);
Datum val = PG_GETARG_DATUM(1);
Datum return_state = prev_state;
int64 total_rows = PG_GETARG_INT64(3);
rownum = (int64) ceil(percentile * (total_rows));
int64 *cnt;
if (!fcinfo->flinfo->fn_extra)
{
cnt = (int64 *) MemoryContextAllocZero(fcinfo->flinfo->fn_mcxt, sizeof(int64));
*cnt = 1;
fcinfo->flinfo->fn_extra = cnt;
}
else
{
cnt = (int64 *) fcinfo->flinfo->fn_extra;
}
if(*cnt == rownum - 1)
{
return_state = val;
}
*cnt = *cnt + 1;
if(*cnt >= total_rows)
{
/* Clean up, so the next group can see NULL for fn_extra */
pfree(cnt);
fcinfo->flinfo->fn_extra = NULL;
}
PG_RETURN_DATUM(return_state);
}
/*
* Final function for gp_percentile
*/
Datum
gp_percentile_final(PG_FUNCTION_ARGS)
{
/* Get and check the percentile argument */
if (PG_ARGISNULL(0))
PG_RETURN_NULL();
PG_RETURN_DATUM(PG_GETARG_DATUM(0));
}
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