Line data Source code
1 : /*-------------------------------------------------------------------------
2 : *
3 : * nodeBitmapAnd.c
4 : * routines to handle BitmapAnd nodes.
5 : *
6 : * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
7 : * Portions Copyright (c) 1994, Regents of the University of California
8 : *
9 : *
10 : * IDENTIFICATION
11 : * src/backend/executor/nodeBitmapAnd.c
12 : *
13 : *-------------------------------------------------------------------------
14 : */
15 : /*
16 : * INTERFACE ROUTINES
17 : * ExecInitBitmapAnd - initialize the BitmapAnd node
18 : * MultiExecBitmapAnd - retrieve the result bitmap from the node
19 : * ExecEndBitmapAnd - shut down the BitmapAnd node
20 : * ExecReScanBitmapAnd - rescan the BitmapAnd node
21 : *
22 : * NOTES
23 : * BitmapAnd nodes don't make use of their left and right
24 : * subtrees, rather they maintain a list of subplans,
25 : * much like Append nodes. The logic is much simpler than
26 : * Append, however, since we needn't cope with forward/backward
27 : * execution.
28 : */
29 :
30 : #include "postgres.h"
31 :
32 : #include "executor/executor.h"
33 : #include "executor/instrument.h"
34 : #include "executor/nodeBitmapAnd.h"
35 : #include "nodes/tidbitmap.h"
36 :
37 :
38 : /* ----------------------------------------------------------------
39 : * ExecBitmapAnd
40 : *
41 : * stub for pro forma compliance
42 : * ----------------------------------------------------------------
43 : */
44 : static TupleTableSlot *
45 0 : ExecBitmapAnd(PlanState *pstate)
46 : {
47 0 : elog(ERROR, "BitmapAnd node does not support ExecProcNode call convention");
48 : return NULL;
49 : }
50 :
51 : /* ----------------------------------------------------------------
52 : * ExecInitBitmapAnd
53 : *
54 : * Begin all of the subscans of the BitmapAnd node.
55 : * ----------------------------------------------------------------
56 : */
57 : BitmapAndState *
58 146 : ExecInitBitmapAnd(BitmapAnd *node, EState *estate, int eflags)
59 : {
60 146 : BitmapAndState *bitmapandstate = makeNode(BitmapAndState);
61 : PlanState **bitmapplanstates;
62 : int nplans;
63 : int i;
64 : ListCell *l;
65 : Plan *initNode;
66 :
67 : /* check for unsupported flags */
68 : Assert(!(eflags & (EXEC_FLAG_BACKWARD | EXEC_FLAG_MARK)));
69 :
70 : /*
71 : * Set up empty vector of subplan states
72 : */
73 146 : nplans = list_length(node->bitmapplans);
74 :
75 146 : bitmapplanstates = (PlanState **) palloc0(nplans * sizeof(PlanState *));
76 :
77 : /*
78 : * create new BitmapAndState for our BitmapAnd node
79 : */
80 146 : bitmapandstate->ps.plan = (Plan *) node;
81 146 : bitmapandstate->ps.state = estate;
82 146 : bitmapandstate->ps.ExecProcNode = ExecBitmapAnd;
83 146 : bitmapandstate->bitmapplans = bitmapplanstates;
84 146 : bitmapandstate->nplans = nplans;
85 :
86 : /*
87 : * call ExecInitNode on each of the plans to be executed and save the
88 : * results into the array "bitmapplanstates".
89 : */
90 146 : i = 0;
91 438 : foreach(l, node->bitmapplans)
92 : {
93 292 : initNode = (Plan *) lfirst(l);
94 292 : bitmapplanstates[i] = ExecInitNode(initNode, estate, eflags);
95 292 : i++;
96 : }
97 :
98 : /*
99 : * Miscellaneous initialization
100 : *
101 : * BitmapAnd plans don't have expression contexts because they never call
102 : * ExecQual or ExecProject. They don't need any tuple slots either.
103 : */
104 :
105 146 : return bitmapandstate;
106 : }
107 :
108 : /* ----------------------------------------------------------------
109 : * MultiExecBitmapAnd
110 : * ----------------------------------------------------------------
111 : */
112 : Node *
113 114 : MultiExecBitmapAnd(BitmapAndState *node)
114 : {
115 : PlanState **bitmapplans;
116 : int nplans;
117 : int i;
118 114 : TIDBitmap *result = NULL;
119 :
120 : /* must provide our own instrumentation support */
121 114 : if (node->ps.instrument)
122 0 : InstrStartNode(node->ps.instrument);
123 :
124 : /*
125 : * get information from the node
126 : */
127 114 : bitmapplans = node->bitmapplans;
128 114 : nplans = node->nplans;
129 :
130 : /*
131 : * Scan all the subplans and AND their result bitmaps
132 : */
133 338 : for (i = 0; i < nplans; i++)
134 : {
135 228 : PlanState *subnode = bitmapplans[i];
136 : TIDBitmap *subresult;
137 :
138 228 : subresult = (TIDBitmap *) MultiExecProcNode(subnode);
139 :
140 228 : if (!subresult || !IsA(subresult, TIDBitmap))
141 0 : elog(ERROR, "unrecognized result from subplan");
142 :
143 228 : if (result == NULL)
144 114 : result = subresult; /* first subplan */
145 : else
146 : {
147 114 : tbm_intersect(result, subresult);
148 114 : tbm_free(subresult);
149 : }
150 :
151 : /*
152 : * If at any stage we have a completely empty bitmap, we can fall out
153 : * without evaluating the remaining subplans, since ANDing them can no
154 : * longer change the result. (Note: the fact that indxpath.c orders
155 : * the subplans by selectivity should make this case more likely to
156 : * occur.)
157 : */
158 228 : if (tbm_is_empty(result))
159 4 : break;
160 : }
161 :
162 114 : if (result == NULL)
163 0 : elog(ERROR, "BitmapAnd doesn't support zero inputs");
164 :
165 : /* must provide our own instrumentation support */
166 114 : if (node->ps.instrument)
167 0 : InstrStopNode(node->ps.instrument, 0 /* XXX */ );
168 :
169 114 : return (Node *) result;
170 : }
171 :
172 : /* ----------------------------------------------------------------
173 : * ExecEndBitmapAnd
174 : *
175 : * Shuts down the subscans of the BitmapAnd node.
176 : *
177 : * Returns nothing of interest.
178 : * ----------------------------------------------------------------
179 : */
180 : void
181 146 : ExecEndBitmapAnd(BitmapAndState *node)
182 : {
183 : PlanState **bitmapplans;
184 : int nplans;
185 : int i;
186 :
187 : /*
188 : * get information from the node
189 : */
190 146 : bitmapplans = node->bitmapplans;
191 146 : nplans = node->nplans;
192 :
193 : /*
194 : * shut down each of the subscans (that we've initialized)
195 : */
196 438 : for (i = 0; i < nplans; i++)
197 : {
198 292 : if (bitmapplans[i])
199 292 : ExecEndNode(bitmapplans[i]);
200 : }
201 146 : }
202 :
203 : void
204 82 : ExecReScanBitmapAnd(BitmapAndState *node)
205 : {
206 : int i;
207 :
208 246 : for (i = 0; i < node->nplans; i++)
209 : {
210 164 : PlanState *subnode = node->bitmapplans[i];
211 :
212 : /*
213 : * ExecReScan doesn't know about my subplans, so I have to do
214 : * changed-parameter signaling myself.
215 : */
216 164 : if (node->ps.chgParam != NULL)
217 8 : UpdateChangedParamSet(subnode, node->ps.chgParam);
218 :
219 : /*
220 : * If chgParam of subnode is not null then plan will be re-scanned by
221 : * first ExecProcNode.
222 : */
223 164 : if (subnode->chgParam == NULL)
224 160 : ExecReScan(subnode);
225 : }
226 82 : }
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