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nodeAgg.h
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1 /*-------------------------------------------------------------------------
2  *
3  * nodeAgg.h
4  * prototypes for nodeAgg.c
5  *
6  *
7  * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
8  * Portions Copyright (c) 1994, Regents of the University of California
9  *
10  * src/include/executor/nodeAgg.h
11  *
12  *-------------------------------------------------------------------------
13  */
14 #ifndef NODEAGG_H
15 #define NODEAGG_H
16 
17 #include "access/parallel.h"
18 #include "nodes/execnodes.h"
19 
20 
21 /*
22  * AggStatePerTransData - per aggregate state value information
23  *
24  * Working state for updating the aggregate's state value, by calling the
25  * transition function with an input row. This struct does not store the
26  * information needed to produce the final aggregate result from the transition
27  * state, that's stored in AggStatePerAggData instead. This separation allows
28  * multiple aggregate results to be produced from a single state value.
29  */
30 typedef struct AggStatePerTransData
31 {
32  /*
33  * These values are set up during ExecInitAgg() and do not change
34  * thereafter:
35  */
36 
37  /*
38  * Link to an Aggref expr this state value is for.
39  *
40  * There can be multiple Aggref's sharing the same state value, so long as
41  * the inputs and transition functions are identical and the final
42  * functions are not read-write. This points to the first one of them.
43  */
45 
46  /*
47  * Is this state value actually being shared by more than one Aggref?
48  */
49  bool aggshared;
50 
51  /*
52  * True for ORDER BY and DISTINCT Aggrefs that are not aggpresorted.
53  */
55 
56  /*
57  * Number of aggregated input columns. This includes ORDER BY expressions
58  * in both the plain-agg and ordered-set cases. Ordered-set direct args
59  * are not counted, though.
60  */
61  int numInputs;
62 
63  /*
64  * Number of aggregated input columns to pass to the transfn. This
65  * includes the ORDER BY columns for ordered-set aggs, but not for plain
66  * aggs. (This doesn't count the transition state value!)
67  */
69 
70  /* Oid of the state transition or combine function */
72 
73  /* Oid of the serialization function or InvalidOid */
75 
76  /* Oid of the deserialization function or InvalidOid */
78 
79  /* Oid of state value's datatype */
81 
82  /*
83  * fmgr lookup data for transition function or combine function. Note in
84  * particular that the fn_strict flag is kept here.
85  */
87 
88  /* fmgr lookup data for serialization function */
90 
91  /* fmgr lookup data for deserialization function */
93 
94  /* Input collation derived for aggregate */
96 
97  /* number of sorting columns */
99 
100  /* number of sorting columns to consider in DISTINCT comparisons */
101  /* (this is either zero or the same as numSortCols) */
103 
104  /* deconstructed sorting information (arrays of length numSortCols) */
109 
110  /*
111  * Comparators for input columns --- only set/used when aggregate has
112  * DISTINCT flag. equalfnOne version is used for single-column
113  * comparisons, equalfnMulti for the case of multiple columns.
114  */
117 
118  /*
119  * initial value from pg_aggregate entry
120  */
123 
124  /*
125  * We need the len and byval info for the agg's input and transition data
126  * types in order to know how to copy/delete values.
127  *
128  * Note that the info for the input type is used only when handling
129  * DISTINCT aggs with just one argument, so there is only one input type.
130  */
135 
136  /*
137  * Slots for holding the evaluated input arguments. These are set up
138  * during ExecInitAgg() and then used for each input row requiring either
139  * FILTER or ORDER BY/DISTINCT processing.
140  */
141  TupleTableSlot *sortslot; /* current input tuple */
142  TupleTableSlot *uniqslot; /* used for multi-column DISTINCT */
143  TupleDesc sortdesc; /* descriptor of input tuples */
144  Datum lastdatum; /* used for single-column DISTINCT */
145  bool lastisnull; /* used for single-column DISTINCT */
146  bool haslast; /* got a last value for DISTINCT check */
147 
148  /*
149  * These values are working state that is initialized at the start of an
150  * input tuple group and updated for each input tuple.
151  *
152  * For a simple (non DISTINCT/ORDER BY) aggregate, we just feed the input
153  * values straight to the transition function. If it's DISTINCT or
154  * requires ORDER BY, we pass the input values into a Tuplesort object;
155  * then at completion of the input tuple group, we scan the sorted values,
156  * eliminate duplicates if needed, and run the transition function on the
157  * rest.
158  *
159  * We need a separate tuplesort for each grouping set.
160  */
161 
162  Tuplesortstate **sortstates; /* sort objects, if DISTINCT or ORDER BY */
163 
164  /*
165  * This field is a pre-initialized FunctionCallInfo struct used for
166  * calling this aggregate's transfn. We save a few cycles per row by not
167  * re-initializing the unchanging fields; which isn't much, but it seems
168  * worth the extra space consumption.
169  */
171 
172  /* Likewise for serialization and deserialization functions */
174 
177 
178 /*
179  * AggStatePerAggData - per-aggregate information
180  *
181  * This contains the information needed to call the final function, to produce
182  * a final aggregate result from the state value. If there are multiple
183  * identical Aggrefs in the query, they can all share the same per-agg data.
184  *
185  * These values are set up during ExecInitAgg() and do not change thereafter.
186  */
187 typedef struct AggStatePerAggData
188 {
189  /*
190  * Link to an Aggref expr this state value is for.
191  *
192  * There can be multiple identical Aggref's sharing the same per-agg. This
193  * points to the first one of them.
194  */
196 
197  /* index to the state value which this agg should use */
198  int transno;
199 
200  /* Optional Oid of final function (may be InvalidOid) */
202 
203  /*
204  * fmgr lookup data for final function --- only valid when finalfn_oid is
205  * not InvalidOid.
206  */
208 
209  /*
210  * Number of arguments to pass to the finalfn. This is always at least 1
211  * (the transition state value) plus any ordered-set direct args. If the
212  * finalfn wants extra args then we pass nulls corresponding to the
213  * aggregated input columns.
214  */
216 
217  /* ExprStates for any direct-argument expressions */
219 
220  /*
221  * We need the len and byval info for the agg's result data type in order
222  * to know how to copy/delete values.
223  */
226 
227  /*
228  * "shareable" is false if this agg cannot share state values with other
229  * aggregates because the final function is read-write.
230  */
231  bool shareable;
233 
234 /*
235  * AggStatePerGroupData - per-aggregate-per-group working state
236  *
237  * These values are working state that is initialized at the start of
238  * an input tuple group and updated for each input tuple.
239  *
240  * In AGG_PLAIN and AGG_SORTED modes, we have a single array of these
241  * structs (pointed to by aggstate->pergroup); we re-use the array for
242  * each input group, if it's AGG_SORTED mode. In AGG_HASHED mode, the
243  * hash table contains an array of these structs for each tuple group.
244  *
245  * Logically, the sortstate field belongs in this struct, but we do not
246  * keep it here for space reasons: we don't support DISTINCT aggregates
247  * in AGG_HASHED mode, so there's no reason to use up a pointer field
248  * in every entry of the hashtable.
249  */
250 typedef struct AggStatePerGroupData
251 {
252 #define FIELDNO_AGGSTATEPERGROUPDATA_TRANSVALUE 0
253  Datum transValue; /* current transition value */
254 #define FIELDNO_AGGSTATEPERGROUPDATA_TRANSVALUEISNULL 1
256 
257 #define FIELDNO_AGGSTATEPERGROUPDATA_NOTRANSVALUE 2
258  bool noTransValue; /* true if transValue not set yet */
259 
260  /*
261  * Note: noTransValue initially has the same value as transValueIsNull,
262  * and if true both are cleared to false at the same time. They are not
263  * the same though: if transfn later returns a NULL, we want to keep that
264  * NULL and not auto-replace it with a later input value. Only the first
265  * non-NULL input will be auto-substituted.
266  */
268 
269 /*
270  * AggStatePerPhaseData - per-grouping-set-phase state
271  *
272  * Grouping sets are divided into "phases", where a single phase can be
273  * processed in one pass over the input. If there is more than one phase, then
274  * at the end of input from the current phase, state is reset and another pass
275  * taken over the data which has been re-sorted in the mean time.
276  *
277  * Accordingly, each phase specifies a list of grouping sets and group clause
278  * information, plus each phase after the first also has a sort order.
279  */
280 typedef struct AggStatePerPhaseData
281 {
282  AggStrategy aggstrategy; /* strategy for this phase */
283  int numsets; /* number of grouping sets (or 0) */
284  int *gset_lengths; /* lengths of grouping sets */
285  Bitmapset **grouped_cols; /* column groupings for rollup */
286  ExprState **eqfunctions; /* expression returning equality, indexed by
287  * nr of cols to compare */
288  Agg *aggnode; /* Agg node for phase data */
289  Sort *sortnode; /* Sort node for input ordering for phase */
290 
291  ExprState *evaltrans; /* evaluation of transition functions */
292 
293  /*----------
294  * Cached variants of the compiled expression.
295  * first subscript: 0: outerops; 1: TTSOpsMinimalTuple
296  * second subscript: 0: no NULL check; 1: with NULL check
297  *----------
298  */
301 
302 /*
303  * AggStatePerHashData - per-hashtable state
304  *
305  * When doing grouping sets with hashing, we have one of these for each
306  * grouping set. (When doing hashing without grouping sets, we have just one of
307  * them.)
308  */
309 typedef struct AggStatePerHashData
310 {
311  TupleHashTable hashtable; /* hash table with one entry per group */
312  TupleHashIterator hashiter; /* for iterating through hash table */
313  TupleTableSlot *hashslot; /* slot for loading hash table */
314  FmgrInfo *hashfunctions; /* per-grouping-field hash fns */
315  Oid *eqfuncoids; /* per-grouping-field equality fns */
316  int numCols; /* number of hash key columns */
317  int numhashGrpCols; /* number of columns in hash table */
318  int largestGrpColIdx; /* largest col required for hashing */
319  AttrNumber *hashGrpColIdxInput; /* hash col indices in input slot */
320  AttrNumber *hashGrpColIdxHash; /* indices in hash table tuples */
321  Agg *aggnode; /* original Agg node, for numGroups etc. */
323 
324 
325 extern AggState *ExecInitAgg(Agg *node, EState *estate, int eflags);
326 extern void ExecEndAgg(AggState *node);
327 extern void ExecReScanAgg(AggState *node);
328 
329 extern Size hash_agg_entry_size(int numTrans, Size tupleWidth,
330  Size transitionSpace);
331 extern void hash_agg_set_limits(double hashentrysize, double input_groups,
332  int used_bits, Size *mem_limit,
333  uint64 *ngroups_limit, int *num_partitions);
334 
335 /* parallel instrumentation support */
336 extern void ExecAggEstimate(AggState *node, ParallelContext *pcxt);
337 extern void ExecAggInitializeDSM(AggState *node, ParallelContext *pcxt);
338 extern void ExecAggInitializeWorker(AggState *node, ParallelWorkerContext *pwcxt);
339 extern void ExecAggRetrieveInstrumentation(AggState *node);
340 
341 #endif /* NODEAGG_H */
int16 AttrNumber
Definition: attnum.h:21
signed short int16
Definition: c.h:482
size_t Size
Definition: c.h:594
tuplehash_iterator TupleHashIterator
Definition: execnodes.h:833
void ExecAggEstimate(AggState *node, ParallelContext *pcxt)
Definition: nodeAgg.c:4684
struct AggStatePerAggData AggStatePerAggData
void ExecAggInitializeWorker(AggState *node, ParallelWorkerContext *pwcxt)
Definition: nodeAgg.c:4730
struct AggStatePerTransData AggStatePerTransData
AggState * ExecInitAgg(Agg *node, EState *estate, int eflags)
Definition: nodeAgg.c:3174
void ExecAggRetrieveInstrumentation(AggState *node)
Definition: nodeAgg.c:4743
struct AggStatePerGroupData AggStatePerGroupData
void ExecReScanAgg(AggState *node)
Definition: nodeAgg.c:4365
Size hash_agg_entry_size(int numTrans, Size tupleWidth, Size transitionSpace)
Definition: nodeAgg.c:1695
void ExecAggInitializeDSM(AggState *node, ParallelContext *pcxt)
Definition: nodeAgg.c:4705
struct AggStatePerPhaseData AggStatePerPhaseData
struct AggStatePerHashData AggStatePerHashData
void ExecEndAgg(AggState *node)
Definition: nodeAgg.c:4305
void hash_agg_set_limits(double hashentrysize, double input_groups, int used_bits, Size *mem_limit, uint64 *ngroups_limit, int *num_partitions)
Definition: nodeAgg.c:1799
AggStrategy
Definition: nodes.h:342
uintptr_t Datum
Definition: postgres.h:64
unsigned int Oid
Definition: postgres_ext.h:31
FmgrInfo finalfn
Definition: nodeAgg.h:207
bool resulttypeByVal
Definition: nodeAgg.h:225
List * aggdirectargs
Definition: nodeAgg.h:218
Aggref * aggref
Definition: nodeAgg.h:195
int16 resulttypeLen
Definition: nodeAgg.h:224
FmgrInfo * hashfunctions
Definition: nodeAgg.h:314
TupleHashTable hashtable
Definition: nodeAgg.h:311
TupleTableSlot * hashslot
Definition: nodeAgg.h:313
TupleHashIterator hashiter
Definition: nodeAgg.h:312
AttrNumber * hashGrpColIdxHash
Definition: nodeAgg.h:320
AttrNumber * hashGrpColIdxInput
Definition: nodeAgg.h:319
Bitmapset ** grouped_cols
Definition: nodeAgg.h:285
ExprState * evaltrans
Definition: nodeAgg.h:291
ExprState * evaltrans_cache[2][2]
Definition: nodeAgg.h:299
ExprState ** eqfunctions
Definition: nodeAgg.h:286
AggStrategy aggstrategy
Definition: nodeAgg.h:282
bool * sortNullsFirst
Definition: nodeAgg.h:108
FmgrInfo serialfn
Definition: nodeAgg.h:89
FmgrInfo equalfnOne
Definition: nodeAgg.h:115
TupleDesc sortdesc
Definition: nodeAgg.h:143
TupleTableSlot * sortslot
Definition: nodeAgg.h:141
FmgrInfo transfn
Definition: nodeAgg.h:86
Aggref * aggref
Definition: nodeAgg.h:44
ExprState * equalfnMulti
Definition: nodeAgg.h:116
Tuplesortstate ** sortstates
Definition: nodeAgg.h:162
TupleTableSlot * uniqslot
Definition: nodeAgg.h:142
FmgrInfo deserialfn
Definition: nodeAgg.h:92
FunctionCallInfo deserialfn_fcinfo
Definition: nodeAgg.h:175
AttrNumber * sortColIdx
Definition: nodeAgg.h:105
FunctionCallInfo serialfn_fcinfo
Definition: nodeAgg.h:173
FunctionCallInfo transfn_fcinfo
Definition: nodeAgg.h:170
Definition: plannodes.h:995
Definition: fmgr.h:57
Definition: pg_list.h:54