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pg_publication.c
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1 /*-------------------------------------------------------------------------
2  *
3  * pg_publication.c
4  * publication C API manipulation
5  *
6  * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
7  * Portions Copyright (c) 1994, Regents of the University of California
8  *
9  * IDENTIFICATION
10  * pg_publication.c
11  *
12  *-------------------------------------------------------------------------
13  */
14 
15 #include "postgres.h"
16 
17 #include "funcapi.h"
18 #include "miscadmin.h"
19 
20 #include "access/genam.h"
21 #include "access/hash.h"
22 #include "access/heapam.h"
23 #include "access/htup_details.h"
24 #include "access/xact.h"
25 
26 #include "catalog/catalog.h"
27 #include "catalog/dependency.h"
28 #include "catalog/index.h"
29 #include "catalog/indexing.h"
30 #include "catalog/namespace.h"
31 #include "catalog/objectaccess.h"
32 #include "catalog/objectaddress.h"
33 #include "catalog/pg_type.h"
34 #include "catalog/pg_publication.h"
36 
37 #include "utils/array.h"
38 #include "utils/builtins.h"
39 #include "utils/catcache.h"
40 #include "utils/fmgroids.h"
41 #include "utils/inval.h"
42 #include "utils/lsyscache.h"
43 #include "utils/rel.h"
44 #include "utils/syscache.h"
45 
46 /*
47  * Check if relation can be in given publication and throws appropriate
48  * error if not.
49  */
50 static void
52 {
53  /* Must be table */
54  if (RelationGetForm(targetrel)->relkind != RELKIND_RELATION)
55  ereport(ERROR,
56  (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
57  errmsg("\"%s\" is not a table",
58  RelationGetRelationName(targetrel)),
59  errdetail("Only tables can be added to publications.")));
60 
61  /* Can't be system table */
62  if (IsCatalogRelation(targetrel))
63  ereport(ERROR,
64  (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
65  errmsg("\"%s\" is a system table",
66  RelationGetRelationName(targetrel)),
67  errdetail("System tables cannot be added to publications.")));
68 
69  /* UNLOGGED and TEMP relations cannot be part of publication. */
70  if (!RelationNeedsWAL(targetrel))
71  ereport(ERROR,
72  (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
73  errmsg("table \"%s\" cannot be replicated",
74  RelationGetRelationName(targetrel)),
75  errdetail("Temporary and unlogged relations cannot be replicated.")));
76 }
77 
78 /*
79  * Returns if relation represented by oid and Form_pg_class entry
80  * is publishable.
81  *
82  * Does same checks as the above, but does not need relation to be opened
83  * and also does not throw errors.
84  */
85 static bool
87 {
88  return reltuple->relkind == RELKIND_RELATION &&
89  !IsCatalogClass(relid, reltuple) &&
90  reltuple->relpersistence == RELPERSISTENCE_PERMANENT &&
91  /*
92  * Also exclude any tables created as part of initdb. This mainly
93  * affects the preinstalled information_schema.
94  * Note that IsCatalogClass() only checks for these inside pg_catalog
95  * and toast schemas.
96  */
97  relid >= FirstNormalObjectId;
98 }
99 
100 /*
101  * Insert new publication / relation mapping.
102  */
105  bool if_not_exists)
106 {
107  Relation rel;
108  HeapTuple tup;
110  bool nulls[Natts_pg_publication_rel];
111  Oid relid = RelationGetRelid(targetrel);
112  Oid prrelid;
113  Publication *pub = GetPublication(pubid);
114  ObjectAddress myself,
115  referenced;
116 
118 
119  /*
120  * Check for duplicates. Note that this does not really prevent
121  * duplicates, it's here just to provide nicer error message in common
122  * case. The real protection is the unique key on the catalog.
123  */
125  ObjectIdGetDatum(pubid)))
126  {
128 
129  if (if_not_exists)
130  return InvalidObjectAddress;
131 
132  ereport(ERROR,
134  errmsg("relation \"%s\" is already member of publication \"%s\"",
135  RelationGetRelationName(targetrel), pub->name)));
136  }
137 
139 
140  /* Form a tuple. */
141  memset(values, 0, sizeof(values));
142  memset(nulls, false, sizeof(nulls));
143 
144  values[Anum_pg_publication_rel_prpubid - 1] =
145  ObjectIdGetDatum(pubid);
146  values[Anum_pg_publication_rel_prrelid - 1] =
147  ObjectIdGetDatum(relid);
148 
149  tup = heap_form_tuple(RelationGetDescr(rel), values, nulls);
150 
151  /* Insert tuple into catalog. */
152  prrelid = CatalogTupleInsert(rel, tup);
153  heap_freetuple(tup);
154 
155  ObjectAddressSet(myself, PublicationRelRelationId, prrelid);
156 
157  /* Add dependency on the publication */
158  ObjectAddressSet(referenced, PublicationRelationId, pubid);
159  recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
160 
161  /* Add dependency on the relation */
162  ObjectAddressSet(referenced, RelationRelationId, relid);
163  recordDependencyOn(&myself, &referenced, DEPENDENCY_AUTO);
164 
165  /* Close the table. */
167 
168  /* Invalidate relcache so that publication info is rebuilt. */
169  CacheInvalidateRelcache(targetrel);
170 
171  return myself;
172 }
173 
174 
175 /*
176  * Gets list of publication oids for a relation oid.
177  */
178 List *
180 {
181  List *result = NIL;
182  CatCList *pubrellist;
183  int i;
184 
185  /* Find all publications associated with the relation. */
187  ObjectIdGetDatum(relid));
188  for (i = 0; i < pubrellist->n_members; i++)
189  {
190  HeapTuple tup = &pubrellist->members[i]->tuple;
191  Oid pubid = ((Form_pg_publication_rel) GETSTRUCT(tup))->prpubid;
192 
193  result = lappend_oid(result, pubid);
194  }
195 
196  ReleaseSysCacheList(pubrellist);
197 
198  return result;
199 }
200 
201 /*
202  * Gets list of relation oids for a publication.
203  *
204  * This should only be used for normal publications, the FOR ALL TABLES
205  * should use GetAllTablesPublicationRelations().
206  */
207 List *
209 {
210  List *result;
211  Relation pubrelsrel;
212  ScanKeyData scankey;
213  SysScanDesc scan;
214  HeapTuple tup;
215 
216  /* Find all publications associated with the relation. */
218 
219  ScanKeyInit(&scankey,
221  BTEqualStrategyNumber, F_OIDEQ,
222  ObjectIdGetDatum(pubid));
223 
224  scan = systable_beginscan(pubrelsrel, PublicationRelMapIndexId, true,
225  NULL, 1, &scankey);
226 
227  result = NIL;
228  while (HeapTupleIsValid(tup = systable_getnext(scan)))
229  {
231 
232  pubrel = (Form_pg_publication_rel) GETSTRUCT(tup);
233 
234  result = lappend_oid(result, pubrel->prrelid);
235  }
236 
237  systable_endscan(scan);
238  heap_close(pubrelsrel, AccessShareLock);
239 
240  return result;
241 }
242 
243 /*
244  * Gets list of publication oids for publications marked as FOR ALL TABLES.
245  */
246 List *
248 {
249  List *result;
250  Relation rel;
251  ScanKeyData scankey;
252  SysScanDesc scan;
253  HeapTuple tup;
254 
255  /* Find all publications that are marked as for all tables. */
257 
258  ScanKeyInit(&scankey,
260  BTEqualStrategyNumber, F_BOOLEQ,
261  BoolGetDatum(true));
262 
263  scan = systable_beginscan(rel, InvalidOid, false,
264  NULL, 1, &scankey);
265 
266  result = NIL;
267  while (HeapTupleIsValid(tup = systable_getnext(scan)))
268  result = lappend_oid(result, HeapTupleGetOid(tup));
269 
270  systable_endscan(scan);
272 
273  return result;
274 }
275 
276 /*
277  * Gets list of all relation published by FOR ALL TABLES publication(s).
278  */
279 List *
281 {
282  Relation classRel;
283  ScanKeyData key[1];
284  HeapScanDesc scan;
285  HeapTuple tuple;
286  List *result = NIL;
287 
289 
290  ScanKeyInit(&key[0],
292  BTEqualStrategyNumber, F_CHAREQ,
294 
295  scan = heap_beginscan_catalog(classRel, 1, key);
296 
297  while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
298  {
299  Oid relid = HeapTupleGetOid(tuple);
300  Form_pg_class relForm = (Form_pg_class) GETSTRUCT(tuple);
301 
302  if (is_publishable_class(relid, relForm))
303  result = lappend_oid(result, relid);
304  }
305 
306  heap_endscan(scan);
307  heap_close(classRel, AccessShareLock);
308 
309  return result;
310 }
311 
312 /*
313  * Get publication using oid
314  *
315  * The Publication struct and it's data are palloced here.
316  */
317 Publication *
319 {
320  HeapTuple tup;
321  Publication *pub;
322  Form_pg_publication pubform;
323 
325 
326  if (!HeapTupleIsValid(tup))
327  elog(ERROR, "cache lookup failed for publication %u", pubid);
328 
329  pubform = (Form_pg_publication) GETSTRUCT(tup);
330 
331  pub = (Publication *) palloc(sizeof(Publication));
332  pub->oid = pubid;
333  pub->name = pstrdup(NameStr(pubform->pubname));
334  pub->alltables = pubform->puballtables;
335  pub->pubactions.pubinsert = pubform->pubinsert;
336  pub->pubactions.pubupdate = pubform->pubupdate;
337  pub->pubactions.pubdelete = pubform->pubdelete;
338 
339  ReleaseSysCache(tup);
340 
341  return pub;
342 }
343 
344 
345 /*
346  * Get Publication using name.
347  */
348 Publication *
349 GetPublicationByName(const char *pubname, bool missing_ok)
350 {
351  Oid oid;
352 
354  if (!OidIsValid(oid))
355  {
356  if (missing_ok)
357  return NULL;
358 
359  ereport(ERROR,
360  (errcode(ERRCODE_UNDEFINED_OBJECT),
361  errmsg("publication \"%s\" does not exist", pubname)));
362  }
363 
364  return GetPublication(oid);
365 }
366 
367 /*
368  * get_publication_oid - given a publication name, look up the OID
369  *
370  * If missing_ok is false, throw an error if name not found. If true, just
371  * return InvalidOid.
372  */
373 Oid
374 get_publication_oid(const char *pubname, bool missing_ok)
375 {
376  Oid oid;
377 
379  if (!OidIsValid(oid) && !missing_ok)
380  ereport(ERROR,
381  (errcode(ERRCODE_UNDEFINED_OBJECT),
382  errmsg("publication \"%s\" does not exist", pubname)));
383  return oid;
384 }
385 
386 /*
387  * get_publication_name - given a publication Oid, look up the name
388  */
389 char *
391 {
392  HeapTuple tup;
393  char *pubname;
394  Form_pg_publication pubform;
395 
397 
398  if (!HeapTupleIsValid(tup))
399  elog(ERROR, "cache lookup failed for publication %u", pubid);
400 
401  pubform = (Form_pg_publication) GETSTRUCT(tup);
402  pubname = pstrdup(NameStr(pubform->pubname));
403 
404  ReleaseSysCache(tup);
405 
406  return pubname;
407 }
408 
409 /*
410  * Returns Oids of tables in a publication.
411  */
412 Datum
414 {
415  FuncCallContext *funcctx;
416  char *pubname = text_to_cstring(PG_GETARG_TEXT_PP(0));
417  Publication *publication;
418  List *tables;
419  ListCell **lcp;
420 
421  /* stuff done only on the first call of the function */
422  if (SRF_IS_FIRSTCALL())
423  {
424  MemoryContext oldcontext;
425 
426  /* create a function context for cross-call persistence */
427  funcctx = SRF_FIRSTCALL_INIT();
428 
429  /* switch to memory context appropriate for multiple function calls */
430  oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
431 
432  publication = GetPublicationByName(pubname, false);
433  if (publication->alltables)
435  else
436  tables = GetPublicationRelations(publication->oid);
437  lcp = (ListCell **) palloc(sizeof(ListCell *));
438  *lcp = list_head(tables);
439  funcctx->user_fctx = (void *) lcp;
440 
441  MemoryContextSwitchTo(oldcontext);
442  }
443 
444  /* stuff done on every call of the function */
445  funcctx = SRF_PERCALL_SETUP();
446  lcp = (ListCell **) funcctx->user_fctx;
447 
448  while (*lcp != NULL)
449  {
450  Oid relid = lfirst_oid(*lcp);
451 
452  *lcp = lnext(*lcp);
453  SRF_RETURN_NEXT(funcctx, ObjectIdGetDatum(relid));
454  }
455 
456  SRF_RETURN_DONE(funcctx);
457 }
#define NIL
Definition: pg_list.h:69
PublicationActions pubactions
bool IsCatalogRelation(Relation relation)
Definition: catalog.c:91
int n_members
Definition: catcache.h:154
List * GetAllTablesPublicationRelations(void)
void systable_endscan(SysScanDesc sysscan)
Definition: genam.c:493
#define GETSTRUCT(TUP)
Definition: htup_details.h:656
void heap_endscan(HeapScanDesc scan)
Definition: heapam.c:1581
#define PublicationRelMapIndexId
Definition: indexing.h:344
bool IsCatalogClass(Oid relid, Form_pg_class reltuple)
Definition: catalog.c:103
#define RelationGetDescr(relation)
Definition: rel.h:425
#define SRF_IS_FIRSTCALL()
Definition: funcapi.h:285
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Definition: mcxt.c:1165
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Definition: rel.h:407
#define RelationRelationId
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Definition: palloc.h:109
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Definition: lockdefs.h:36
int errcode(int sqlerrcode)
Definition: elog.c:575
#define PublicationRelationId
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Definition: pg_depend.c:44
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Definition: heaptuple.c:692
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Definition: heapam.h:97
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Definition: heaptuple.c:1374
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Definition: list.c:164
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Definition: funcapi.h:289
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Definition: genam.c:322
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Definition: syscache.h:149
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Definition: transam.h:94
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Definition: fmgr.h:270
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Definition: syscache.h:176
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Definition: pg_class.h:170
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Definition: catcache.h:155
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Definition: funcapi.h:291
#define Anum_pg_class_relkind
Definition: pg_class.h:118
List * GetRelationPublications(Oid relid)
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Definition: genam.c:410
Publication * GetPublication(Oid pubid)
#define ObjectIdGetDatum(X)
Definition: postgres.h:515
#define ERROR
Definition: elog.h:43
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Definition: indexing.c:162
static void check_publication_add_relation(Relation targetrel)
#define Anum_pg_publication_rel_prpubid
#define Anum_pg_publication_rel_prrelid
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Definition: lockdefs.h:38
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Definition: elog.c:873
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Definition: postgres.h:586
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Definition: syscache.h:194
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Definition: heapam.c:1402
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Definition: elog.h:122
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Definition: syscache.h:203
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Definition: syscache.c:1083
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Definition: heapam.c:1781
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Definition: heapam.c:1287
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#define InvalidOid
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Definition: c.h:226
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Definition: rel.h:502
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Definition: objectaddress.h:40
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Definition: inval.c:1223
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Definition: mcxt.c:891
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Definition: elog.c:797
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FormData_pg_publication_rel * Form_pg_publication_rel
int i
#define Natts_pg_publication_rel
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Definition: scankey.c:76
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