Age Owner Branch data TLA Line data Source code
1 : : /*-------------------------------------------------------------------------
2 : : *
3 : : * rewriteGraphTable.c
4 : : * Support for rewriting GRAPH_TABLE clauses.
5 : : *
6 : : * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
7 : : * Portions Copyright (c) 1994, Regents of the University of California
8 : : *
9 : : * IDENTIFICATION
10 : : * src/backend/rewrite/rewriteGraphTable.c
11 : : *
12 : : *-------------------------------------------------------------------------
13 : : */
14 : : #include "postgres.h"
15 : :
16 : : #include "access/genam.h"
17 : : #include "access/sysattr.h"
18 : : #include "access/table.h"
19 : : #include "access/htup_details.h"
20 : : #include "catalog/pg_operator.h"
21 : : #include "catalog/pg_propgraph_element.h"
22 : : #include "catalog/pg_propgraph_element_label.h"
23 : : #include "catalog/pg_propgraph_label.h"
24 : : #include "catalog/pg_propgraph_label_property.h"
25 : : #include "catalog/pg_propgraph_property.h"
26 : : #include "miscadmin.h"
27 : : #include "nodes/makefuncs.h"
28 : : #include "nodes/nodeFuncs.h"
29 : : #include "optimizer/optimizer.h"
30 : : #include "parser/analyze.h"
31 : : #include "parser/parse_collate.h"
32 : : #include "parser/parse_func.h"
33 : : #include "parser/parse_node.h"
34 : : #include "parser/parse_oper.h"
35 : : #include "parser/parse_relation.h"
36 : : #include "parser/parsetree.h"
37 : : #include "parser/parse_graphtable.h"
38 : : #include "rewrite/rewriteGraphTable.h"
39 : : #include "rewrite/rewriteHandler.h"
40 : : #include "rewrite/rewriteManip.h"
41 : : #include "utils/array.h"
42 : : #include "utils/builtins.h"
43 : : #include "utils/fmgroids.h"
44 : : #include "utils/lsyscache.h"
45 : : #include "utils/ruleutils.h"
46 : : #include "utils/syscache.h"
47 : :
48 : :
49 : : /*
50 : : * Represents one path factor in a path.
51 : : *
52 : : * In a non-cyclic path, one path factor corresponds to one element pattern.
53 : : *
54 : : * In a cyclic path, one path factor corresponds to all the element patterns with
55 : : * the same variable name.
56 : : */
57 : : struct path_factor
58 : : {
59 : : GraphElementPatternKind kind;
60 : : const char *variable;
61 : : Node *labelexpr;
62 : : Node *whereClause;
63 : : int factorpos; /* Position of this path factor in the list of
64 : : * path factors representing a given path
65 : : * pattern. */
66 : : List *labeloids; /* OIDs of all the labels referenced in
67 : : * labelexpr. */
68 : : /* Links to adjacent vertex path factors if this is an edge path factor. */
69 : : struct path_factor *src_pf;
70 : : struct path_factor *dest_pf;
71 : : };
72 : :
73 : : /*
74 : : * Represents one property graph element (vertex or edge) in the path.
75 : : *
76 : : * Label expression in an element pattern resolves into a set of elements. We
77 : : * create one path_element object for each of those elements.
78 : : */
79 : : struct path_element
80 : : {
81 : : /* Path factor from which this element is derived. */
82 : : struct path_factor *path_factor;
83 : : Oid elemoid;
84 : : Oid reloid;
85 : : /* Source and destination vertex elements for an edge element. */
86 : : Oid srcvertexid;
87 : : Oid destvertexid;
88 : : /* Source and destination conditions for an edge element. */
89 : : List *src_quals;
90 : : List *dest_quals;
91 : : };
92 : :
93 : : static Node *replace_property_refs(Oid propgraphid, Node *node, const List *mappings);
94 : : static List *build_edge_vertex_link_quals(HeapTuple edgetup, int edgerti, int refrti, Oid refid, AttrNumber catalog_key_attnum, AttrNumber catalog_ref_attnum, AttrNumber catalog_eqop_attnum);
95 : : static List *generate_queries_for_path_pattern(RangeTblEntry *rte, List *path_pattern);
96 : : static Query *generate_query_for_graph_path(RangeTblEntry *rte, List *graph_path);
97 : : static Node *generate_setop_from_pathqueries(List *pathqueries, List **rtable, List **targetlist);
98 : : static List *generate_queries_for_path_pattern_recurse(RangeTblEntry *rte, List *pathqueries, List *cur_path, List *path_elem_lists, int elempos);
99 : : static Query *generate_query_for_empty_path_pattern(RangeTblEntry *rte);
100 : : static Query *generate_union_from_pathqueries(List **pathqueries);
101 : : static List *get_path_elements_for_path_factor(Oid propgraphid, struct path_factor *pf);
102 : : static bool is_property_associated_with_label(Oid labeloid, Oid propoid);
103 : : static Node *get_element_property_expr(Oid elemoid, Oid propoid, int rtindex);
104 : :
105 : : /*
106 : : * Convert GRAPH_TABLE clause into a subquery using relational
107 : : * operators.
108 : : */
109 : : Query *
106 peter@eisentraut.org 110 :GNC 487 : rewriteGraphTable(Query *parsetree, int rt_index)
111 : : {
112 : : RangeTblEntry *rte;
113 : : Query *graph_table_query;
114 : : List *path_pattern;
115 : 487 : List *pathqueries = NIL;
116 : :
117 : 487 : rte = rt_fetch(rt_index, parsetree->rtable);
118 : :
119 [ - + ]: 487 : Assert(list_length(rte->graph_pattern->path_pattern_list) == 1);
120 : :
121 : 487 : path_pattern = linitial(rte->graph_pattern->path_pattern_list);
122 : 487 : pathqueries = generate_queries_for_path_pattern(rte, path_pattern);
123 : 447 : graph_table_query = generate_union_from_pathqueries(&pathqueries);
124 : :
125 : 447 : AcquireRewriteLocks(graph_table_query, true, false);
126 : :
127 : 447 : rte->rtekind = RTE_SUBQUERY;
128 : 447 : rte->subquery = graph_table_query;
129 : 447 : rte->lateral = true;
130 : :
131 : : /*
132 : : * Reset no longer applicable fields, to appease
133 : : * WRITE_READ_PARSE_PLAN_TREES.
134 : : */
135 : 447 : rte->graph_pattern = NULL;
136 : 447 : rte->graph_table_columns = NIL;
137 : :
138 : 447 : return parsetree;
139 : : }
140 : :
141 : : /*
142 : : * Generate queries representing the given path pattern applied to the given
143 : : * property graph.
144 : : *
145 : : * A path pattern consists of one or more element patterns. Each of the element
146 : : * patterns may be satisfied by multiple elements. A path satisfying the given
147 : : * path pattern consists of one element from each element pattern. There can be
148 : : * as many paths as the number of combinations of the elements. A path pattern
149 : : * in itself is a K-partite graph where K = number of element patterns in the
150 : : * path pattern. The possible paths are computed by performing a DFS in this
151 : : * graph. The DFS is implemented as recursion. Each of these paths is converted
152 : : * into a query connecting all the elements in that path. Set of these queries is
153 : : * returned.
154 : : *
155 : : * Between every two vertex elements in the path there is an edge element that
156 : : * connects them. An edge connects two vertices identified by the source and
157 : : * destination keys respectively. The connection between an edge and its
158 : : * adjacent vertex is naturally computed as an equi-join between edge and vertex
159 : : * table on their respective keys. Hence the query representing one path
160 : : * consists of JOINs between edge and vertex tables.
161 : : *
162 : : * generate_queries_for_path_pattern() starts the recursion but actual work is
163 : : * done by generate_queries_for_path_pattern_recurse().
164 : : * generate_query_for_graph_path() constructs a query for a given path.
165 : : *
166 : : * A path pattern may end up producing no path if any of the element patterns
167 : : * yields no elements or the edge patterns yield no edges connecting adjacent
168 : : * vertex patterns. In such a case a dummy query which returns no result is
169 : : * returned (generate_query_for_empty_path_pattern()).
170 : : *
171 : : * 'path_pattern' is given path pattern to be applied on the property graph in
172 : : * the GRAPH_TABLE clause represented by given 'rte'.
173 : : */
174 : : static List *
175 : 487 : generate_queries_for_path_pattern(RangeTblEntry *rte, List *path_pattern)
176 : : {
177 : 487 : List *pathqueries = NIL;
178 : 487 : List *path_elem_lists = NIL;
179 : 487 : int factorpos = 0;
180 : 487 : List *path_factors = NIL;
181 : 487 : struct path_factor *prev_pf = NULL;
182 : :
183 [ - + ]: 487 : Assert(list_length(path_pattern) > 0);
184 : :
185 : : /*
186 : : * Create a list of path factors representing the given path pattern
187 : : * linking edge path factors to their adjacent vertex path factors.
188 : : *
189 : : * While doing that merge element patterns with the same variable name
190 : : * into a single path_factor.
191 : : */
192 [ + - + + : 2457 : foreach_node(GraphElementPattern, gep, path_pattern)
+ + ]
193 : : {
194 : 1507 : struct path_factor *pf = NULL;
195 : :
196 : : /*
197 : : * Unsupported conditions should have been caught by the parser
198 : : * itself. We have corresponding Asserts here to document the
199 : : * assumptions in this code.
200 : : */
201 [ + + + + : 1507 : Assert(gep->kind == VERTEX_PATTERN || IS_EDGE_PATTERN(gep->kind));
+ + - + ]
202 [ - + ]: 1507 : Assert(!gep->quantifier);
203 : :
204 [ + + + + : 4524 : foreach_ptr(struct path_factor, other, path_factors)
+ + ]
205 : : {
206 [ + + + + ]: 1670 : if (gep->variable && other->variable &&
207 [ + + ]: 1099 : strcmp(gep->variable, other->variable) == 0)
208 : : {
209 [ + + ]: 152 : if (other->kind != gep->kind)
210 [ + - ]: 4 : ereport(ERROR,
211 : : (errcode(ERRCODE_WRONG_OBJECT_TYPE),
212 : : errmsg("element patterns with same variable name \"%s\" but different element pattern types",
213 : : gep->variable)));
214 : :
215 : : /*
216 : : * If both the element patterns have label expressions, they
217 : : * need to be conjuncted, which is not supported right now.
218 : : *
219 : : * However, an empty label expression means all labels.
220 : : * Conjunction of any label expression with all labels is the
221 : : * expression itself. Hence if only one of the two element
222 : : * patterns has a label expression use that expression.
223 : : */
224 [ + + ]: 148 : if (!other->labelexpr)
225 : 136 : other->labelexpr = gep->labelexpr;
226 [ + + + - ]: 12 : else if (gep->labelexpr && !equal(other->labelexpr, gep->labelexpr))
227 [ + - ]: 4 : ereport(ERROR,
228 : : (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
229 : : errmsg("element patterns with same variable name \"%s\" but different label expressions are not supported",
230 : : gep->variable)));
231 : :
232 : : /*
233 : : * If two element patterns have the same variable name, they
234 : : * represent the same set of graph elements and hence are
235 : : * constrained by conditions from both the element patterns.
236 : : */
237 [ + + ]: 144 : if (!other->whereClause)
238 : 128 : other->whereClause = gep->whereClause;
239 [ + + ]: 16 : else if (gep->whereClause)
240 : 8 : other->whereClause = (Node *) makeBoolExpr(AND_EXPR,
241 : 8 : list_make2(other->whereClause, gep->whereClause),
242 : : -1);
243 : 144 : pf = other;
244 : 144 : break;
245 : : }
246 : : }
247 : :
248 [ + + ]: 1499 : if (!pf)
249 : : {
97 250 : 1355 : pf = palloc0_object(struct path_factor);
251 : 1355 : pf->factorpos = factorpos++;
252 : 1355 : pf->kind = gep->kind;
253 : 1355 : pf->labelexpr = gep->labelexpr;
254 : 1355 : pf->variable = gep->variable;
255 : 1355 : pf->whereClause = gep->whereClause;
256 : :
257 : 1355 : path_factors = lappend(path_factors, pf);
258 : : }
259 : :
260 : : /*
261 : : * Setup links to the previous path factor in the path.
262 : : *
263 : : * If the previous path factor represents an edge, this path factor
264 : : * represents an adjacent vertex; the source vertex for an edge
265 : : * pointing left or the destination vertex for an edge pointing right.
266 : : * If this path factor represents an edge, the previous path factor
267 : : * represents an adjacent vertex; source vertex for an edge pointing
268 : : * right or the destination vertex for an edge pointing left.
269 : : *
270 : : * Edge pointing in any direction is treated similar to that pointing
271 : : * in right direction here. When constructing a query in
272 : : * generate_query_for_graph_path(), we will try links in both the
273 : : * directions.
274 : : *
275 : : * If multiple edge patterns share the same variable name, they
276 : : * constrain the adjacent vertex patterns since an edge can connect
277 : : * only one pair of vertices. These adjacent vertex patterns need to
278 : : * be merged even though they have different variables. Such element
279 : : * patterns form a walk of graph where vertex and edges are repeated.
280 : : * For example, in (a)-[b]->(c)<-[b]-(d), (a) and (d) represent the
281 : : * same vertex element. This is slightly harder to implement and
282 : : * probably less useful. Hence not supported for now.
283 : : */
106 284 [ + + ]: 1499 : if (prev_pf)
285 : : {
286 [ + + + + ]: 1012 : if (prev_pf->kind == EDGE_PATTERN_RIGHT || prev_pf->kind == EDGE_PATTERN_ANY)
287 : : {
288 [ + - + - : 494 : Assert(!IS_EDGE_PATTERN(pf->kind));
- + ]
289 [ + + - + ]: 494 : if (prev_pf->dest_pf && prev_pf->dest_pf != pf)
106 peter@eisentraut.org 290 [ # # ]:UNC 0 : ereport(ERROR,
291 : : errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
292 : : errmsg("an edge cannot connect more than two vertices even in a cyclic pattern"));
106 peter@eisentraut.org 293 :GNC 494 : prev_pf->dest_pf = pf;
294 : : }
295 [ + + ]: 518 : else if (prev_pf->kind == EDGE_PATTERN_LEFT)
296 : : {
297 [ + - + - : 8 : Assert(!IS_EDGE_PATTERN(pf->kind));
- + ]
298 [ - + - - ]: 8 : if (prev_pf->src_pf && prev_pf->src_pf != pf)
106 peter@eisentraut.org 299 [ # # ]:UNC 0 : ereport(ERROR,
300 : : errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
301 : : errmsg("an edge cannot connect more than two vertices even in a cyclic pattern"));
106 peter@eisentraut.org 302 :GNC 8 : prev_pf->src_pf = pf;
303 : : }
304 : : else
305 : : {
95 306 [ - + ]: 510 : Assert(prev_pf->kind == VERTEX_PATTERN);
307 [ + + + + : 510 : Assert(IS_EDGE_PATTERN(pf->kind));
- + ]
308 : : }
309 : :
106 310 [ + + + + ]: 1012 : if (pf->kind == EDGE_PATTERN_RIGHT || pf->kind == EDGE_PATTERN_ANY)
311 : : {
312 [ + - + - : 502 : Assert(!IS_EDGE_PATTERN(prev_pf->kind));
- + ]
313 [ + + + + ]: 502 : if (pf->src_pf && pf->src_pf != prev_pf)
314 [ + - ]: 4 : ereport(ERROR,
315 : : errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
316 : : errmsg("an edge cannot connect more than two vertices even in a cyclic pattern"));
317 : 498 : pf->src_pf = prev_pf;
318 : : }
319 [ + + ]: 510 : else if (pf->kind == EDGE_PATTERN_LEFT)
320 : : {
321 [ + - + - : 8 : Assert(!IS_EDGE_PATTERN(prev_pf->kind));
- + ]
322 [ - + - - ]: 8 : if (pf->dest_pf && pf->dest_pf != prev_pf)
106 peter@eisentraut.org 323 [ # # ]:UNC 0 : ereport(ERROR,
324 : : errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
325 : : errmsg("an edge cannot connect more than two vertices even in a cyclic pattern"));
106 peter@eisentraut.org 326 :GNC 8 : pf->dest_pf = prev_pf;
327 : : }
328 : : else
329 : : {
95 330 [ - + ]: 502 : Assert(pf->kind == VERTEX_PATTERN);
331 [ + + + + : 502 : Assert(IS_EDGE_PATTERN(prev_pf->kind));
- + ]
332 : : }
333 : : }
334 : :
106 335 : 1495 : prev_pf = pf;
336 : : }
337 : :
338 : : /*
339 : : * Collect list of elements for each path factor. Do this after all the
340 : : * edge links are setup correctly.
341 : : */
342 [ + - + + : 2241 : foreach_ptr(struct path_factor, pf, path_factors)
+ + ]
343 : 1299 : path_elem_lists = lappend(path_elem_lists,
344 : 1307 : get_path_elements_for_path_factor(rte->relid, pf));
345 : :
346 : 467 : pathqueries = generate_queries_for_path_pattern_recurse(rte, pathqueries,
347 : : NIL, path_elem_lists, 0);
348 [ + + ]: 447 : if (!pathqueries)
349 : 4 : pathqueries = list_make1(generate_query_for_empty_path_pattern(rte));
350 : :
351 : 447 : return pathqueries;
352 : : }
353 : :
354 : : /*
355 : : * Recursive workhorse function of generate_queries_for_path_pattern().
356 : : *
357 : : * `elempos` is the position of the next element being added in the path being
358 : : * built.
359 : : */
360 : : static List *
361 : 9658 : generate_queries_for_path_pattern_recurse(RangeTblEntry *rte, List *pathqueries, List *cur_path, List *path_elem_lists, int elempos)
362 : : {
363 : 9658 : List *path_elems = list_nth_node(List, path_elem_lists, elempos);
364 : :
365 : : /* Guard against stack overflow due to complex path patterns. */
67 366 : 9658 : check_stack_depth();
367 : :
106 368 [ + - + + : 50162 : foreach_ptr(struct path_element, pe, path_elems)
+ + ]
369 : : {
370 : : /* Update current path being built with current element. */
371 : 30974 : cur_path = lappend(cur_path, pe);
372 : :
373 : : /*
374 : : * If this is the last element in the path, generate query for the
375 : : * completed path. Else recurse processing the next element.
376 : : */
377 [ + + ]: 30974 : if (list_length(path_elem_lists) == list_length(cur_path))
378 : : {
379 : 21783 : Query *pathquery = generate_query_for_graph_path(rte, cur_path);
380 : :
381 [ - + ]: 21763 : Assert(elempos == list_length(path_elem_lists) - 1);
382 [ + + ]: 21763 : if (pathquery)
383 : 811 : pathqueries = lappend(pathqueries, pathquery);
384 : : }
385 : : else
386 : 9191 : pathqueries = generate_queries_for_path_pattern_recurse(rte, pathqueries,
387 : : cur_path,
388 : : path_elem_lists,
389 : : elempos + 1);
390 : : /* Make way for the next element at the same position. */
391 : 30910 : cur_path = list_delete_last(cur_path);
392 : : }
393 : :
394 : 9594 : return pathqueries;
395 : : }
396 : :
397 : : /*
398 : : * Construct a query representing given graph path.
399 : : *
400 : : * The query contains:
401 : : *
402 : : * 1. targetlist corresponding to the COLUMNS clause of GRAPH_TABLE clause
403 : : *
404 : : * 2. quals corresponding to the WHERE clause of individual elements, WHERE
405 : : * clause in GRAPH_TABLE clause and quals representing edge-vertex links.
406 : : *
407 : : * 3. fromlist containing all elements in the path
408 : : *
409 : : * The collations of property expressions are obtained from the catalog. The
410 : : * collations of expressions in COLUMNS and WHERE clauses are assigned before
411 : : * rewriting the graph table. The collations of the edge-vertex link quals are
412 : : * assigned when crafting those quals. Thus everything in the query that requires
413 : : * collation assignment has been taken care of already. No separate collation
414 : : * assignment is required in this function.
415 : : *
416 : : * More details in the prologue of generate_queries_for_path_pattern().
417 : : */
418 : : static Query *
419 : 21783 : generate_query_for_graph_path(RangeTblEntry *rte, List *graph_path)
420 : : {
421 : 21783 : Query *path_query = makeNode(Query);
422 : 21783 : List *fromlist = NIL;
423 : 21783 : List *qual_exprs = NIL;
424 : : List *vars;
425 : :
426 : 21783 : path_query->commandType = CMD_SELECT;
427 : :
428 [ + - + + : 50089 : foreach_ptr(struct path_element, pe, graph_path)
+ + ]
429 : : {
430 : 48427 : struct path_factor *pf = pe->path_factor;
431 : : RangeTblRef *rtr;
432 : : Relation rel;
433 : : ParseNamespaceItem *pni;
434 : :
435 [ + + + + : 48427 : Assert(pf->kind == VERTEX_PATTERN || IS_EDGE_PATTERN(pf->kind));
+ + - + ]
436 : :
437 : : /* Add conditions representing edge connections. */
438 [ + + + + : 48427 : if (IS_EDGE_PATTERN(pf->kind))
+ + ]
439 : 2908 : {
440 : : struct path_element *src_pe;
441 : : struct path_element *dest_pe;
442 : 23860 : Expr *edge_qual = NULL;
443 : :
444 [ + - - + ]: 23860 : Assert(pf->src_pf && pf->dest_pf);
445 : 23860 : src_pe = list_nth(graph_path, pf->src_pf->factorpos);
446 : 23860 : dest_pe = list_nth(graph_path, pf->dest_pf->factorpos);
447 : :
448 : : /* Make sure that the links of adjacent vertices are correct. */
449 [ + - - + ]: 23860 : Assert(pf->src_pf == src_pe->path_factor &&
450 : : pf->dest_pf == dest_pe->path_factor);
451 : :
452 [ + + ]: 23860 : if (src_pe->elemoid == pe->srcvertexid &&
453 [ + + ]: 8248 : dest_pe->elemoid == pe->destvertexid)
454 : 2900 : edge_qual = makeBoolExpr(AND_EXPR,
455 : 2900 : list_concat(copyObject(pe->src_quals),
456 : 2900 : copyObject(pe->dest_quals)),
457 : : -1);
458 : :
459 : : /*
460 : : * An edge pattern in any direction matches edges in both
461 : : * directions, try swapping source and destination. When the
462 : : * source and destination is the same vertex table, quals
463 : : * corresponding to either direction may get satisfied. Hence OR
464 : : * the quals corresponding to both the directions.
465 : : */
466 [ + + ]: 23860 : if (pf->kind == EDGE_PATTERN_ANY &&
467 [ + + ]: 224 : dest_pe->elemoid == pe->srcvertexid &&
468 [ + + ]: 80 : src_pe->elemoid == pe->destvertexid)
469 : : {
470 : 24 : List *src_quals = copyObject(pe->dest_quals);
471 : 24 : List *dest_quals = copyObject(pe->src_quals);
472 : : Expr *rev_edge_qual;
473 : :
474 : : /* Swap the source and destination varnos in the quals. */
475 : 24 : ChangeVarNodes((Node *) dest_quals, pe->path_factor->src_pf->factorpos + 1,
476 : 24 : pe->path_factor->dest_pf->factorpos + 1, 0);
477 : 24 : ChangeVarNodes((Node *) src_quals, pe->path_factor->dest_pf->factorpos + 1,
478 : 24 : pe->path_factor->src_pf->factorpos + 1, 0);
479 : :
480 : 24 : rev_edge_qual = makeBoolExpr(AND_EXPR, list_concat(src_quals, dest_quals), -1);
481 [ + + ]: 24 : if (edge_qual)
482 : 16 : edge_qual = makeBoolExpr(OR_EXPR, list_make2(edge_qual, rev_edge_qual), -1);
483 : : else
484 : 8 : edge_qual = rev_edge_qual;
485 : : }
486 : :
487 : : /*
488 : : * If the given edge element does not connect the adjacent vertex
489 : : * elements in this path, the path is broken. Abandon this path as
490 : : * it won't return any rows.
491 : : */
492 [ + + ]: 23860 : if (edge_qual == NULL)
493 : 20952 : return NULL;
494 : :
495 : 2908 : qual_exprs = lappend(qual_exprs, edge_qual);
496 : : }
497 : : else
498 [ + - - + ]: 24567 : Assert(!pe->src_quals && !pe->dest_quals);
499 : :
500 : : /*
501 : : * Create RangeTblEntry for this element table.
502 : : *
503 : : * SQL/PGQ standard (Ref. Section 11.19, Access rule 2 and General
504 : : * rule 4) does not specify whose access privileges to use when
505 : : * accessing the element tables: property graph owner's or current
506 : : * user's. It is safer to use current user's privileges to avoid
507 : : * unprivileged data access through a property graph. This is inline
508 : : * with the views being security_invoker by default.
509 : : */
510 : 27475 : rel = table_open(pe->reloid, AccessShareLock);
511 : 27475 : pni = addRangeTableEntryForRelation(make_parsestate(NULL), rel, AccessShareLock,
512 : : NULL, true, false);
513 : 27475 : table_close(rel, NoLock);
514 : 27475 : path_query->rtable = lappend(path_query->rtable, pni->p_rte);
515 : 27475 : path_query->rteperminfos = lappend(path_query->rteperminfos, pni->p_perminfo);
516 : 27475 : pni->p_rte->perminfoindex = list_length(path_query->rteperminfos);
517 : 27475 : rtr = makeNode(RangeTblRef);
518 : 27475 : rtr->rtindex = list_length(path_query->rtable);
519 : 27475 : fromlist = lappend(fromlist, rtr);
520 : :
521 : : /*
522 : : * Make sure that the assumption mentioned in create_pe_for_element()
523 : : * holds true; that the elements' RangeTblEntrys are added in the
524 : : * order in which their respective path factors appear in the list of
525 : : * path factors representing the path pattern.
526 : : */
527 [ - + ]: 27475 : Assert(pf->factorpos + 1 == rtr->rtindex);
528 : :
529 [ + + ]: 27475 : if (pf->whereClause)
530 : : {
531 : : Node *tr;
532 : :
533 : 3740 : tr = replace_property_refs(rte->relid, pf->whereClause, list_make1(pe));
534 : :
535 : 3740 : qual_exprs = lappend(qual_exprs, tr);
536 : : }
537 : : }
538 : :
539 [ + + ]: 831 : if (rte->graph_pattern->whereClause)
540 : : {
541 : 322 : Node *path_quals = replace_property_refs(rte->relid,
542 : 322 : (Node *) rte->graph_pattern->whereClause,
543 : : graph_path);
544 : :
545 : 322 : qual_exprs = lappend(qual_exprs, path_quals);
546 : : }
547 : :
548 [ + + ]: 1558 : path_query->jointree = makeFromExpr(fromlist,
549 : 727 : qual_exprs ? (Node *) makeBoolExpr(AND_EXPR, qual_exprs, -1) : NULL);
550 : :
551 : : /* Construct query targetlist from COLUMNS specification of GRAPH_TABLE. */
552 : 831 : path_query->targetList = castNode(List,
553 : : replace_property_refs(rte->relid,
554 : : (Node *) rte->graph_table_columns,
555 : : graph_path));
556 : :
557 : : /*
558 : : * Mark the columns being accessed in the path query as requiring SELECT
559 : : * privilege. Any lateral columns should have been handled when the
560 : : * corresponding ColumnRefs were transformed. Ignore those here.
561 : : */
562 : 811 : vars = pull_vars_of_level((Node *) list_make2(qual_exprs, path_query->targetList), 0);
563 [ + + + + : 9469 : foreach_node(Var, var, vars)
+ + ]
564 : : {
565 : 7847 : RTEPermissionInfo *perminfo = getRTEPermissionInfo(path_query->rteperminfos,
566 : 7847 : rt_fetch(var->varno, path_query->rtable));
567 : :
568 : : /* Must offset the attnum to fit in a bitmapset */
569 : 7847 : perminfo->selectedCols = bms_add_member(perminfo->selectedCols,
570 : 7847 : var->varattno - FirstLowInvalidHeapAttributeNumber);
571 : : }
572 : :
573 : 811 : return path_query;
574 : : }
575 : :
576 : : /*
577 : : * Construct a query which would not return any rows.
578 : : *
579 : : * More details in the prologue of generate_queries_for_path_pattern().
580 : : */
581 : : static Query *
582 : 4 : generate_query_for_empty_path_pattern(RangeTblEntry *rte)
583 : : {
584 : 4 : Query *query = makeNode(Query);
585 : :
586 : 4 : query->commandType = CMD_SELECT;
587 : 4 : query->rtable = NIL;
588 : 4 : query->rteperminfos = NIL;
589 : 4 : query->jointree = makeFromExpr(NIL, (Node *) makeBoolConst(false, false));
590 : :
591 : : /*
592 : : * Even though no rows are returned, the result still projects the same
593 : : * columns as projected by GRAPH_TABLE clause. Do this by constructing a
594 : : * target list full of NULL values.
595 : : */
596 [ + - + + : 16 : foreach_node(TargetEntry, te, rte->graph_table_columns)
+ + ]
597 : : {
598 : 8 : Node *nte = (Node *) te->expr;
599 : :
600 : 8 : te->expr = (Expr *) makeNullConst(exprType(nte), exprTypmod(nte), exprCollation(nte));
601 : 8 : query->targetList = lappend(query->targetList, te);
602 : : }
603 : :
604 : 4 : return query;
605 : : }
606 : :
607 : : /*
608 : : * Construct a query which is UNION of given path queries.
609 : : *
610 : : * The UNION query derives collations of its targetlist entries from the
611 : : * corresponding targetlist entries of the path queries. The targetlists of path
612 : : * queries being UNION'ed already have collations assigned. No separate
613 : : * collation assignment required in this function.
614 : : *
615 : : * The function destroys given pathqueries list while constructing
616 : : * SetOperationStmt recursively. Hence the function always returns with
617 : : * `pathqueries` set to NIL.
618 : : */
619 : : static Query *
620 : 447 : generate_union_from_pathqueries(List **pathqueries)
621 : : {
622 : 447 : List *rtable = NIL;
623 : 447 : Query *sampleQuery = linitial_node(Query, *pathqueries);
624 : : SetOperationStmt *sostmt;
625 : : Query *union_query;
626 : : int resno;
627 : : ListCell *lctl,
628 : : *lct,
629 : : *lcm,
630 : : *lcc;
631 : :
632 [ - + ]: 447 : Assert(list_length(*pathqueries) > 0);
633 : :
634 : : /* If there's only one pathquery, no need to construct a UNION query. */
635 [ + + ]: 447 : if (list_length(*pathqueries) == 1)
636 : : {
637 : 317 : *pathqueries = NIL;
638 : 317 : return sampleQuery;
639 : : }
640 : :
641 : 130 : sostmt = castNode(SetOperationStmt,
642 : : generate_setop_from_pathqueries(*pathqueries, &rtable, NULL));
643 : :
644 : : /* Encapsulate the set operation statement into a Query. */
645 : 130 : union_query = makeNode(Query);
646 : 130 : union_query->commandType = CMD_SELECT;
647 : 130 : union_query->rtable = rtable;
648 : 130 : union_query->setOperations = (Node *) sostmt;
649 : 130 : union_query->rteperminfos = NIL;
650 : 130 : union_query->jointree = makeFromExpr(NIL, NULL);
651 : :
652 : : /*
653 : : * Generate dummy targetlist for outer query using column names from one
654 : : * of the queries and common datatypes/collations of topmost set
655 : : * operation. It shouldn't matter which query. Also it shouldn't matter
656 : : * which RT index is used as varno in the target list entries, as long as
657 : : * it corresponds to a real RT entry; else funny things may happen when
658 : : * the tree is mashed by rule rewriting. So we use 1 since there's always
659 : : * one RT entry at least.
660 : : */
661 [ - + ]: 130 : Assert(rt_fetch(1, rtable));
662 : 130 : union_query->targetList = NULL;
663 : 130 : resno = 1;
664 [ + - + + : 477 : forfour(lct, sostmt->colTypes,
+ - + + +
- + + + -
+ + + + +
- + - + -
+ + ]
665 : : lcm, sostmt->colTypmods,
666 : : lcc, sostmt->colCollations,
667 : : lctl, sampleQuery->targetList)
668 : : {
669 : 347 : Oid colType = lfirst_oid(lct);
670 : 347 : int32 colTypmod = lfirst_int(lcm);
671 : 347 : Oid colCollation = lfirst_oid(lcc);
672 : 347 : TargetEntry *sample_tle = (TargetEntry *) lfirst(lctl);
673 : : char *colName;
674 : : TargetEntry *tle;
675 : : Var *var;
676 : :
677 [ - + ]: 347 : Assert(!sample_tle->resjunk);
678 : 347 : colName = pstrdup(sample_tle->resname);
679 : 347 : var = makeVar(1, sample_tle->resno, colType, colTypmod, colCollation, 0);
680 : 347 : var->location = exprLocation((Node *) sample_tle->expr);
681 : 347 : tle = makeTargetEntry((Expr *) var, (AttrNumber) resno++, colName, false);
682 : 347 : union_query->targetList = lappend(union_query->targetList, tle);
683 : : }
684 : :
685 : 130 : *pathqueries = NIL;
686 : 130 : return union_query;
687 : : }
688 : :
689 : : /*
690 : : * Construct a query which is UNION of all the given path queries.
691 : : *
692 : : * The function destroys given pathqueries list while constructing
693 : : * SetOperationStmt recursively.
694 : : */
695 : : static Node *
696 : 628 : generate_setop_from_pathqueries(List *pathqueries, List **rtable, List **targetlist)
697 : : {
698 : : SetOperationStmt *sostmt;
699 : : Query *lquery;
700 : : Node *rarg;
701 : 628 : RangeTblRef *lrtr = makeNode(RangeTblRef);
702 : : List *rtargetlist;
703 : : ParseNamespaceItem *pni;
704 : :
705 : : /* Guard against stack overflow due to many path queries. */
67 706 : 628 : check_stack_depth();
707 : :
708 : : /* Recursion termination condition. */
106 709 [ + + ]: 628 : if (list_length(pathqueries) == 0)
710 : : {
711 : 130 : *targetlist = NIL;
712 : 130 : return NULL;
713 : : }
714 : :
715 : 498 : lquery = linitial_node(Query, pathqueries);
716 : :
717 : : /*
718 : : * Each path query will become a subquery of the UNION statement. So any
719 : : * Vars that already refer outside the path query must be adjusted for
720 : : * additional query level.
721 : : */
25 722 : 498 : IncrementVarSublevelsUp((Node *) lquery, 1, 1);
723 : :
106 724 : 498 : pni = addRangeTableEntryForSubquery(make_parsestate(NULL), lquery, NULL,
725 : : false, false);
726 : 498 : *rtable = lappend(*rtable, pni->p_rte);
727 : 498 : lrtr->rtindex = list_length(*rtable);
728 : 498 : rarg = generate_setop_from_pathqueries(list_delete_first(pathqueries), rtable, &rtargetlist);
729 [ + + ]: 498 : if (rarg == NULL)
730 : : {
731 : : /*
732 : : * No further path queries in the list. Convert the last query into a
733 : : * RangeTblRef as expected by SetOperationStmt. Extract a list of the
734 : : * non-junk TLEs for upper-level processing.
735 : : */
736 [ + - ]: 130 : if (targetlist)
737 : : {
738 : 130 : *targetlist = NIL;
739 [ + - + + : 607 : foreach_node(TargetEntry, tle, lquery->targetList)
+ + ]
740 : : {
741 [ + - ]: 347 : if (!tle->resjunk)
742 : 347 : *targetlist = lappend(*targetlist, tle);
743 : : }
744 : : }
745 : 130 : return (Node *) lrtr;
746 : : }
747 : :
748 : 368 : sostmt = makeNode(SetOperationStmt);
749 : 368 : sostmt->op = SETOP_UNION;
750 : 368 : sostmt->all = true;
751 : 368 : sostmt->larg = (Node *) lrtr;
752 : 368 : sostmt->rarg = rarg;
753 : 368 : constructSetOpTargetlist(NULL, sostmt, lquery->targetList, rtargetlist, targetlist, "UNION", false);
754 : :
755 : 368 : return (Node *) sostmt;
756 : : }
757 : :
758 : : /*
759 : : * Construct a path_element object for the graph element given by `elemoid`
760 : : * satisfied by the path factor `pf`.
761 : : *
762 : : * If the type of graph element does not fit the element pattern kind, the
763 : : * function returns NULL.
764 : : */
765 : : static struct path_element *
766 : 4546 : create_pe_for_element(struct path_factor *pf, Oid elemoid)
767 : : {
768 : 4546 : HeapTuple eletup = SearchSysCache1(PROPGRAPHELOID, ObjectIdGetDatum(elemoid));
769 : : Form_pg_propgraph_element pgeform;
770 : : struct path_element *pe;
771 : :
772 [ - + ]: 4546 : if (!eletup)
106 peter@eisentraut.org 773 [ # # ]:UNC 0 : elog(ERROR, "cache lookup failed for property graph element %u", elemoid);
106 peter@eisentraut.org 774 :GNC 4546 : pgeform = ((Form_pg_propgraph_element) GETSTRUCT(eletup));
775 : :
776 [ + + + + ]: 4546 : if ((pgeform->pgekind == PGEKIND_VERTEX && pf->kind != VERTEX_PATTERN) ||
777 [ + + + + : 3936 : (pgeform->pgekind == PGEKIND_EDGE && !IS_EDGE_PATTERN(pf->kind)))
+ + + + ]
778 : : {
779 : 1894 : ReleaseSysCache(eletup);
780 : 1894 : return NULL;
781 : : }
782 : :
783 : 2652 : pe = palloc0_object(struct path_element);
784 : 2652 : pe->path_factor = pf;
785 : 2652 : pe->elemoid = elemoid;
786 : 2652 : pe->reloid = pgeform->pgerelid;
787 : :
788 : : /*
789 : : * When a path is converted into a query
790 : : * (generate_query_for_graph_path()), a RangeTblEntry will be created for
791 : : * every element in the path. Fixing rtindexes of RangeTblEntrys here
792 : : * makes it possible to craft elements' qual expressions only once while
793 : : * we have access to the catalog entry. Otherwise they need to be crafted
794 : : * as many times as the number of paths a given element appears in,
795 : : * fetching catalog entry again each time. Hence we simply assume
796 : : * RangeTblEntrys will be created in the same order in which the
797 : : * corresponding path factors appear in the list of path factors
798 : : * representing a path pattern. That way their rtindexes will be same as
799 : : * path_factor::factorpos + 1.
800 : : */
801 [ + + + + : 2652 : if (IS_EDGE_PATTERN(pf->kind))
+ + ]
802 : : {
803 : 1224 : pe->srcvertexid = pgeform->pgesrcvertexid;
804 : 1224 : pe->destvertexid = pgeform->pgedestvertexid;
805 [ + - - + ]: 1224 : Assert(pf->src_pf && pf->dest_pf);
806 : :
807 : 1224 : pe->src_quals = build_edge_vertex_link_quals(eletup, pf->factorpos + 1, pf->src_pf->factorpos + 1,
808 : : pe->srcvertexid,
809 : : Anum_pg_propgraph_element_pgesrckey,
810 : : Anum_pg_propgraph_element_pgesrcref,
811 : : Anum_pg_propgraph_element_pgesrceqop);
812 : 1224 : pe->dest_quals = build_edge_vertex_link_quals(eletup, pf->factorpos + 1, pf->dest_pf->factorpos + 1,
813 : : pe->destvertexid,
814 : : Anum_pg_propgraph_element_pgedestkey,
815 : : Anum_pg_propgraph_element_pgedestref,
816 : : Anum_pg_propgraph_element_pgedesteqop);
817 : : }
818 : :
819 : 2652 : ReleaseSysCache(eletup);
820 : :
821 : 2652 : return pe;
822 : : }
823 : :
824 : : /*
825 : : * Returns the list of OIDs of graph labels which the given label expression
826 : : * resolves to in the given property graph.
827 : : */
828 : : static List *
829 : 1307 : get_labels_for_expr(Oid propgraphid, Node *labelexpr)
830 : : {
831 : : List *label_oids;
832 : :
833 [ + + ]: 1307 : if (!labelexpr)
834 : : {
835 : : Relation rel;
836 : : SysScanDesc scan;
837 : : ScanKeyData key[1];
838 : : HeapTuple tup;
839 : :
840 : : /*
841 : : * According to section 9.2 "Contextual inference of a set of labels"
842 : : * subclause 2.a.ii of SQL/PGQ standard, element pattern which does
843 : : * not have a label expression is considered to have label expression
844 : : * equivalent to '%|!%' which is set of all labels.
845 : : */
846 : 406 : label_oids = NIL;
847 : 406 : rel = table_open(PropgraphLabelRelationId, AccessShareLock);
848 : 406 : ScanKeyInit(&key[0],
849 : : Anum_pg_propgraph_label_pglpgid,
850 : : BTEqualStrategyNumber,
851 : : F_OIDEQ, ObjectIdGetDatum(propgraphid));
852 : 406 : scan = systable_beginscan(rel, PropgraphLabelGraphNameIndexId,
853 : : true, NULL, 1, key);
854 [ + + ]: 2714 : while (HeapTupleIsValid(tup = systable_getnext(scan)))
855 : : {
856 : 2308 : Form_pg_propgraph_label label = (Form_pg_propgraph_label) GETSTRUCT(tup);
857 : :
858 : 2308 : label_oids = lappend_oid(label_oids, label->oid);
859 : : }
860 : 406 : systable_endscan(scan);
861 : 406 : table_close(rel, AccessShareLock);
862 : : }
863 [ + + ]: 901 : else if (IsA(labelexpr, GraphLabelRef))
864 : : {
865 : 856 : GraphLabelRef *glr = castNode(GraphLabelRef, labelexpr);
866 : :
867 : 856 : label_oids = list_make1_oid(glr->labelid);
868 : : }
869 [ + - ]: 45 : else if (IsA(labelexpr, BoolExpr))
870 : : {
871 : 45 : BoolExpr *be = castNode(BoolExpr, labelexpr);
872 : 45 : List *label_exprs = be->args;
873 : :
874 : 45 : label_oids = NIL;
875 [ + - + + : 184 : foreach_node(GraphLabelRef, glr, label_exprs)
+ + ]
876 : 94 : label_oids = lappend_oid(label_oids, glr->labelid);
877 : : }
878 : : else
879 : : {
880 : : /*
881 : : * should not reach here since gram.y will not generate a label
882 : : * expression with other node types.
883 : : */
106 peter@eisentraut.org 884 [ # # ]:UNC 0 : elog(ERROR, "unsupported label expression node: %d", (int) nodeTag(labelexpr));
885 : : }
886 : :
106 peter@eisentraut.org 887 :GNC 1307 : return label_oids;
888 : : }
889 : :
890 : : /*
891 : : * Return a list of all the graph elements that satisfy the graph element pattern
892 : : * represented by the given path_factor `pf`.
893 : : *
894 : : * First we find all the graph labels that satisfy the label expression in path
895 : : * factor. Each label is associated with one or more graph elements. A union of
896 : : * all such elements satisfies the element pattern. We create one path_element
897 : : * object representing every element whose graph element kind qualifies the
898 : : * element pattern kind. A list of all such path_element objects is returned.
899 : : *
900 : : * Note that we need to report an error for an explicitly specified label which
901 : : * is not associated with any graph element of the required kind. So we have to
902 : : * treat each label separately. Without that requirement we could have collected
903 : : * all the unique elements first and then created path_element objects for them
904 : : * to simplify the code.
905 : : */
906 : : static List *
907 : 1307 : get_path_elements_for_path_factor(Oid propgraphid, struct path_factor *pf)
908 : : {
909 : 1307 : List *label_oids = get_labels_for_expr(propgraphid, pf->labelexpr);
910 : 1307 : List *elem_oids_seen = NIL;
911 : 1307 : List *pf_elem_oids = NIL;
912 : 1307 : List *path_elements = NIL;
913 : 1307 : List *unresolved_labels = NIL;
914 : : Relation rel;
915 : : SysScanDesc scan;
916 : : ScanKeyData key[1];
917 : : HeapTuple tup;
918 : :
919 : : /*
920 : : * A property graph element can be either a vertex or an edge. Other types
921 : : * of path factors like nested path pattern need to be handled separately
922 : : * when supported.
923 : : */
924 [ + + + + : 1307 : Assert(pf->kind == VERTEX_PATTERN || IS_EDGE_PATTERN(pf->kind));
+ + - + ]
925 : :
926 : 1307 : rel = table_open(PropgraphElementLabelRelationId, AccessShareLock);
927 [ + - + + : 5852 : foreach_oid(labeloid, label_oids)
+ + ]
928 : : {
929 : 3254 : bool found = false;
930 : :
931 : 3254 : ScanKeyInit(&key[0],
932 : : Anum_pg_propgraph_element_label_pgellabelid,
933 : : BTEqualStrategyNumber,
934 : : F_OIDEQ, ObjectIdGetDatum(labeloid));
935 : 3254 : scan = systable_beginscan(rel, PropgraphElementLabelLabelIndexId, true,
936 : : NULL, 1, key);
937 [ + + ]: 10853 : while (HeapTupleIsValid(tup = systable_getnext(scan)))
938 : : {
939 : 7599 : Form_pg_propgraph_element_label label_elem = (Form_pg_propgraph_element_label) GETSTRUCT(tup);
940 : 7599 : Oid elem_oid = label_elem->pgelelid;
941 : :
942 [ + + ]: 7599 : if (!list_member_oid(elem_oids_seen, elem_oid))
943 : : {
944 : : /*
945 : : * Create path_element object if the new element qualifies the
946 : : * element pattern kind.
947 : : */
948 : 4546 : struct path_element *pe = create_pe_for_element(pf, elem_oid);
949 : :
950 [ + + ]: 4546 : if (pe)
951 : : {
952 : 2652 : path_elements = lappend(path_elements, pe);
953 : :
954 : : /* Remember qualified elements. */
955 : 2652 : pf_elem_oids = lappend_oid(pf_elem_oids, elem_oid);
956 : 2652 : found = true;
957 : : }
958 : :
959 : : /*
960 : : * Remember qualified and unqualified elements processed so
961 : : * far to avoid processing already processed elements again.
962 : : */
963 : 4546 : elem_oids_seen = lappend_oid(elem_oids_seen, label_elem->pgelelid);
964 : : }
965 [ + + ]: 3053 : else if (list_member_oid(pf_elem_oids, elem_oid))
966 : : {
967 : : /*
968 : : * The graph element is known to qualify the given element
969 : : * pattern. Flag that the current label has at least one
970 : : * qualified element associated with it.
971 : : */
972 : 1565 : found = true;
973 : : }
974 : : }
975 : :
976 [ + + ]: 3254 : if (!found)
977 : : {
978 : : /*
979 : : * We did not find any qualified element associated with this
980 : : * label. The label or its properties can not be associated with
981 : : * the given element pattern. Throw an error if the label was
982 : : * explicitly specified in the element pattern. Otherwise remember
983 : : * it for later use.
984 : : */
985 [ + + ]: 978 : if (!pf->labelexpr)
986 : 970 : unresolved_labels = lappend_oid(unresolved_labels, labeloid);
987 : : else
988 [ + - + - ]: 8 : ereport(ERROR,
989 : : (errcode(ERRCODE_UNDEFINED_OBJECT),
990 : : errmsg("no property graph element of type \"%s\" has label \"%s\" associated with it in property graph \"%s\"",
991 : : pf->kind == VERTEX_PATTERN ? "vertex" : "edge",
992 : : get_propgraph_label_name(labeloid),
993 : : get_rel_name(propgraphid))));
994 : : }
995 : :
996 : 3246 : systable_endscan(scan);
997 : : }
998 : 1299 : table_close(rel, AccessShareLock);
999 : :
1000 : : /*
1001 : : * Remove the labels which were not explicitly mentioned in the label
1002 : : * expression but do not have any qualified elements associated with them.
1003 : : * Properties associated with such labels may not be referenced. See
1004 : : * replace_property_refs_mutator() for more details.
1005 : : */
1006 : 1299 : pf->labeloids = list_difference_oid(label_oids, unresolved_labels);
1007 : :
1008 : 1299 : return path_elements;
1009 : : }
1010 : :
1011 : : /*
1012 : : * Mutating property references into table variables
1013 : : */
1014 : :
1015 : : struct replace_property_refs_context
1016 : : {
1017 : : Oid propgraphid;
1018 : : const List *mappings;
1019 : : };
1020 : :
1021 : : static Node *
1022 : 45160 : replace_property_refs_mutator(Node *node, struct replace_property_refs_context *context)
1023 : : {
1024 [ - + ]: 45160 : if (node == NULL)
106 peter@eisentraut.org 1025 :UNC 0 : return NULL;
106 peter@eisentraut.org 1026 [ + + ]:GNC 45160 : if (IsA(node, Var))
1027 : : {
1028 : 48 : Var *var = (Var *) node;
1029 : 48 : Var *newvar = copyObject(var);
1030 : :
1031 : : /*
1032 : : * If it's already a Var, then it was a lateral reference. Since we
1033 : : * are in a subquery after the rewrite, we have to increase the level
1034 : : * by one.
1035 : : */
1036 : 48 : newvar->varlevelsup++;
1037 : :
1038 : 48 : return (Node *) newvar;
1039 : : }
1040 [ + + ]: 45112 : else if (IsA(node, GraphPropertyRef))
1041 : : {
1042 : 10853 : GraphPropertyRef *gpr = (GraphPropertyRef *) node;
1043 : 10853 : Node *n = NULL;
1044 : 10853 : struct path_element *found_mapping = NULL;
1045 : 10853 : struct path_factor *mapping_factor = NULL;
1046 : 10853 : List *unrelated_labels = NIL;
1047 : :
1048 [ + - + - : 24862 : foreach_ptr(struct path_element, m, context->mappings)
+ + ]
1049 : : {
1050 [ + + + + ]: 14009 : if (m->path_factor->variable && strcmp(gpr->elvarname, m->path_factor->variable) == 0)
1051 : : {
1052 : 10853 : found_mapping = m;
1053 : 10853 : break;
1054 : : }
1055 : : }
1056 : :
1057 : : /*
1058 : : * transformGraphTablePropertyRef() would not create a
1059 : : * GraphPropertyRef for a variable which is not present in the graph
1060 : : * path pattern.
1061 : : */
1062 [ - + ]: 10853 : Assert(found_mapping);
1063 : :
1064 : 10853 : mapping_factor = found_mapping->path_factor;
1065 : :
1066 : : /*
1067 : : * Find property definition for given element through any of the
1068 : : * associated labels qualifying the given element pattern.
1069 : : */
1070 [ + - + + : 59597 : foreach_oid(labeloid, mapping_factor->labeloids)
+ + ]
1071 : : {
1072 : 37891 : Oid elem_labelid = GetSysCacheOid2(PROPGRAPHELEMENTLABELELEMENTLABEL,
1073 : : Anum_pg_propgraph_element_label_oid,
1074 : : ObjectIdGetDatum(found_mapping->elemoid),
1075 : : ObjectIdGetDatum(labeloid));
1076 : :
1077 [ + + ]: 37891 : if (OidIsValid(elem_labelid))
1078 : : {
1079 : 22911 : HeapTuple tup = SearchSysCache2(PROPGRAPHLABELPROP, ObjectIdGetDatum(elem_labelid),
1080 : : ObjectIdGetDatum(gpr->propid));
1081 : :
1082 [ + + ]: 22911 : if (!tup)
1083 : : {
1084 : : /*
1085 : : * The label is associated with the given element but it
1086 : : * is not associated with the required property. Check
1087 : : * next label.
1088 : : */
1089 : 11720 : continue;
1090 : : }
1091 : :
1092 : 11191 : n = stringToNode(TextDatumGetCString(SysCacheGetAttrNotNull(PROPGRAPHLABELPROP,
1093 : : tup, Anum_pg_propgraph_label_property_plpexpr)));
1094 : 11191 : ChangeVarNodes(n, 1, mapping_factor->factorpos + 1, 0);
1095 : :
1096 : 11191 : ReleaseSysCache(tup);
1097 : : }
1098 : : else
1099 : : {
1100 : : /*
1101 : : * Label is not associated with the element but it may be
1102 : : * associated with the property through some other element.
1103 : : * Save it for later use.
1104 : : */
1105 : 14980 : unrelated_labels = lappend_oid(unrelated_labels, labeloid);
1106 : : }
1107 : : }
1108 : :
1109 : : /* See if we can resolve the property in some other way. */
1110 [ + + ]: 10853 : if (!n)
1111 : : {
1112 : 72 : bool prop_associated = false;
1113 : :
1114 [ + + + + : 168 : foreach_oid(loid, unrelated_labels)
+ + ]
1115 : : {
1116 [ + + ]: 76 : if (is_property_associated_with_label(loid, gpr->propid))
1117 : : {
1118 : 52 : prop_associated = true;
1119 : 52 : break;
1120 : : }
1121 : : }
1122 : :
1123 [ + + ]: 72 : if (prop_associated)
1124 : : {
1125 : : /*
1126 : : * The property is associated with at least one of the labels
1127 : : * that satisfy given element pattern. If it's associated with
1128 : : * the given element (through some other label), use
1129 : : * corresponding value expression. Otherwise NULL. Ref.
1130 : : * SQL/PGQ standard section 6.5 Property Reference, General
1131 : : * Rule 2.b.
1132 : : */
1133 : 52 : n = get_element_property_expr(found_mapping->elemoid, gpr->propid,
1134 : 52 : mapping_factor->factorpos + 1);
1135 : :
1136 [ + + ]: 52 : if (!n)
1137 : 48 : n = (Node *) makeNullConst(gpr->typeId, gpr->typmod, gpr->collation);
1138 : : }
1139 : :
1140 : : }
1141 : :
1142 [ + + ]: 10853 : if (!n)
1143 [ + - ]: 20 : ereport(ERROR,
1144 : : errcode(ERRCODE_UNDEFINED_OBJECT),
1145 : : errmsg("property \"%s\" for element variable \"%s\" not found",
1146 : : get_propgraph_property_name(gpr->propid), mapping_factor->variable));
1147 : :
1148 : 10833 : return n;
1149 : : }
1150 : :
1151 : 34259 : return expression_tree_mutator(node, replace_property_refs_mutator, context);
1152 : : }
1153 : :
1154 : : static Node *
1155 : 4893 : replace_property_refs(Oid propgraphid, Node *node, const List *mappings)
1156 : : {
1157 : : struct replace_property_refs_context context;
1158 : :
1159 : 4893 : context.mappings = mappings;
1160 : 4893 : context.propgraphid = propgraphid;
1161 : :
1162 : 4893 : return expression_tree_mutator(node, replace_property_refs_mutator, &context);
1163 : : }
1164 : :
1165 : : /*
1166 : : * Build join qualification expressions between edge and vertex tables.
1167 : : */
1168 : : static List *
1169 : 2448 : build_edge_vertex_link_quals(HeapTuple edgetup, int edgerti, int refrti, Oid refid, AttrNumber catalog_key_attnum, AttrNumber catalog_ref_attnum, AttrNumber catalog_eqop_attnum)
1170 : : {
1171 : 2448 : List *quals = NIL;
1172 : : Form_pg_propgraph_element pgeform;
1173 : : Datum datum;
1174 : : Datum *d1,
1175 : : *d2,
1176 : : *d3;
1177 : : int n1,
1178 : : n2,
1179 : : n3;
1180 : 2448 : ParseState *pstate = make_parsestate(NULL);
1181 : 2448 : Oid refrelid = GetSysCacheOid1(PROPGRAPHELOID, Anum_pg_propgraph_element_pgerelid, ObjectIdGetDatum(refid));
1182 : :
1183 : 2448 : pgeform = (Form_pg_propgraph_element) GETSTRUCT(edgetup);
1184 : :
1185 : 2448 : datum = SysCacheGetAttrNotNull(PROPGRAPHELOID, edgetup, catalog_key_attnum);
1186 : 2448 : deconstruct_array_builtin(DatumGetArrayTypeP(datum), INT2OID, &d1, NULL, &n1);
1187 : :
1188 : 2448 : datum = SysCacheGetAttrNotNull(PROPGRAPHELOID, edgetup, catalog_ref_attnum);
1189 : 2448 : deconstruct_array_builtin(DatumGetArrayTypeP(datum), INT2OID, &d2, NULL, &n2);
1190 : :
1191 : 2448 : datum = SysCacheGetAttrNotNull(PROPGRAPHELOID, edgetup, catalog_eqop_attnum);
1192 : 2448 : deconstruct_array_builtin(DatumGetArrayTypeP(datum), OIDOID, &d3, NULL, &n3);
1193 : :
1194 [ - + ]: 2448 : if (n1 != n2)
106 peter@eisentraut.org 1195 [ # # ]:UNC 0 : elog(ERROR, "array size key (%d) vs ref (%d) mismatch for element ID %u", catalog_key_attnum, catalog_ref_attnum, pgeform->oid);
106 peter@eisentraut.org 1196 [ - + ]:GNC 2448 : if (n1 != n3)
106 peter@eisentraut.org 1197 [ # # ]:UNC 0 : elog(ERROR, "array size key (%d) vs operator (%d) mismatch for element ID %u", catalog_key_attnum, catalog_eqop_attnum, pgeform->oid);
1198 : :
106 peter@eisentraut.org 1199 [ + + ]:GNC 5550 : for (int i = 0; i < n1; i++)
1200 : : {
1201 : 3102 : AttrNumber keyattn = DatumGetInt16(d1[i]);
1202 : 3102 : AttrNumber refattn = DatumGetInt16(d2[i]);
1203 : 3102 : Oid eqop = DatumGetObjectId(d3[i]);
1204 : : Var *keyvar;
1205 : : Var *refvar;
1206 : : Oid atttypid;
1207 : : int32 atttypmod;
1208 : : Oid attcoll;
1209 : : HeapTuple tup;
1210 : : Form_pg_operator opform;
1211 : : List *args;
1212 : : Oid actual_arg_types[2];
1213 : : Oid declared_arg_types[2];
1214 : : OpExpr *linkqual;
1215 : :
1216 : 3102 : get_atttypetypmodcoll(pgeform->pgerelid, keyattn, &atttypid, &atttypmod, &attcoll);
1217 : 3102 : keyvar = makeVar(edgerti, keyattn, atttypid, atttypmod, attcoll, 0);
1218 : 3102 : get_atttypetypmodcoll(refrelid, refattn, &atttypid, &atttypmod, &attcoll);
1219 : 3102 : refvar = makeVar(refrti, refattn, atttypid, atttypmod, attcoll, 0);
1220 : :
1221 : 3102 : tup = SearchSysCache1(OPEROID, ObjectIdGetDatum(eqop));
1222 [ - + ]: 3102 : if (!HeapTupleIsValid(tup))
106 peter@eisentraut.org 1223 [ # # ]:UNC 0 : elog(ERROR, "cache lookup failed for operator %u", eqop);
106 peter@eisentraut.org 1224 :GNC 3102 : opform = (Form_pg_operator) GETSTRUCT(tup);
1225 : : /* An equality operator is a binary operator returning boolean result. */
1226 [ + - + - : 3102 : Assert(opform->oprkind == 'b'
+ - - + ]
1227 : : && RegProcedureIsValid(opform->oprcode)
1228 : : && opform->oprresult == BOOLOID
1229 : : && !get_func_retset(opform->oprcode));
1230 : :
1231 : : /*
1232 : : * Prepare operands and cast them to the types required by the
1233 : : * equality operator. Similar to PK/FK quals, referenced vertex key is
1234 : : * used as left operand and referencing edge key is used as right
1235 : : * operand.
1236 : : */
1237 : 3102 : args = list_make2(refvar, keyvar);
1238 : 3102 : actual_arg_types[0] = exprType((Node *) refvar);
1239 : 3102 : actual_arg_types[1] = exprType((Node *) keyvar);
1240 : 3102 : declared_arg_types[0] = opform->oprleft;
1241 : 3102 : declared_arg_types[1] = opform->oprright;
1242 : 3102 : make_fn_arguments(pstate, args, actual_arg_types, declared_arg_types);
1243 : :
1244 : 3102 : linkqual = makeNode(OpExpr);
1245 : 3102 : linkqual->opno = opform->oid;
1246 : 3102 : linkqual->opfuncid = opform->oprcode;
1247 : 3102 : linkqual->opresulttype = opform->oprresult;
1248 : 3102 : linkqual->opretset = false;
1249 : : /* opcollid and inputcollid will be set by parse_collate.c */
1250 : 3102 : linkqual->args = args;
1251 : 3102 : linkqual->location = -1;
1252 : :
1253 : 3102 : ReleaseSysCache(tup);
1254 : 3102 : quals = lappend(quals, linkqual);
1255 : : }
1256 : :
1257 : 2448 : assign_expr_collations(pstate, (Node *) quals);
1258 : :
1259 : 2448 : return quals;
1260 : : }
1261 : :
1262 : : /*
1263 : : * Check if the given property is associated with the given label.
1264 : : *
1265 : : * A label projects the same set of properties through every element it is
1266 : : * associated with. Find any of the elements and return true if that element is
1267 : : * associated with the given property. False otherwise.
1268 : : */
1269 : : static bool
1270 : 76 : is_property_associated_with_label(Oid labeloid, Oid propoid)
1271 : : {
1272 : : Relation rel;
1273 : : SysScanDesc scan;
1274 : : ScanKeyData key[1];
1275 : : HeapTuple tup;
1276 : 76 : bool associated = false;
1277 : :
1278 : 76 : rel = table_open(PropgraphElementLabelRelationId, RowShareLock);
1279 : 76 : ScanKeyInit(&key[0],
1280 : : Anum_pg_propgraph_element_label_pgellabelid,
1281 : : BTEqualStrategyNumber,
1282 : : F_OIDEQ, ObjectIdGetDatum(labeloid));
1283 : 76 : scan = systable_beginscan(rel, PropgraphElementLabelLabelIndexId,
1284 : : true, NULL, 1, key);
1285 : :
1286 [ + - ]: 76 : if (HeapTupleIsValid(tup = systable_getnext(scan)))
1287 : : {
1288 : 76 : Form_pg_propgraph_element_label ele_label = (Form_pg_propgraph_element_label) GETSTRUCT(tup);
1289 : :
1290 : 76 : associated = SearchSysCacheExists2(PROPGRAPHLABELPROP,
1291 : : ObjectIdGetDatum(ele_label->oid), ObjectIdGetDatum(propoid));
1292 : : }
1293 : 76 : systable_endscan(scan);
1294 : 76 : table_close(rel, RowShareLock);
1295 : :
1296 : 76 : return associated;
1297 : : }
1298 : :
1299 : : /*
1300 : : * If given element has the given property associated with it, through any of
1301 : : * the associated labels, return value expression of the property. Otherwise
1302 : : * NULL.
1303 : : */
1304 : : static Node *
1305 : 52 : get_element_property_expr(Oid elemoid, Oid propoid, int rtindex)
1306 : : {
1307 : : Relation rel;
1308 : : SysScanDesc scan;
1309 : : ScanKeyData key[1];
1310 : : HeapTuple labeltup;
1311 : 52 : Node *n = NULL;
1312 : :
1313 : 52 : rel = table_open(PropgraphElementLabelRelationId, RowShareLock);
1314 : 52 : ScanKeyInit(&key[0],
1315 : : Anum_pg_propgraph_element_label_pgelelid,
1316 : : BTEqualStrategyNumber,
1317 : : F_OIDEQ, ObjectIdGetDatum(elemoid));
1318 : 52 : scan = systable_beginscan(rel, PropgraphElementLabelElementLabelIndexId,
1319 : : true, NULL, 1, key);
1320 : :
1321 [ + + ]: 148 : while (HeapTupleIsValid(labeltup = systable_getnext(scan)))
1322 : : {
1323 : 100 : Form_pg_propgraph_element_label ele_label = (Form_pg_propgraph_element_label) GETSTRUCT(labeltup);
1324 : :
1325 : 100 : HeapTuple proptup = SearchSysCache2(PROPGRAPHLABELPROP,
1326 : : ObjectIdGetDatum(ele_label->oid), ObjectIdGetDatum(propoid));
1327 : :
1328 [ + + ]: 100 : if (!proptup)
1329 : 96 : continue;
1330 : 4 : n = stringToNode(TextDatumGetCString(SysCacheGetAttrNotNull(PROPGRAPHLABELPROP,
1331 : : proptup, Anum_pg_propgraph_label_property_plpexpr)));
1332 : 4 : ChangeVarNodes(n, 1, rtindex, 0);
1333 : :
1334 : 4 : ReleaseSysCache(proptup);
1335 : 4 : break;
1336 : : }
1337 : 52 : systable_endscan(scan);
1338 : 52 : table_close(rel, RowShareLock);
1339 : :
1340 : 52 : return n;
1341 : : }
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