1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
|
/*-------------------------------------------------------------------------
*
* rewriteSupport.c
*
*
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteSupport.c,v 1.50 2002/04/18 20:01:09 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/heapam.h"
#include "catalog/catname.h"
#include "catalog/indexing.h"
#include "rewrite/rewriteSupport.h"
#include "utils/syscache.h"
#ifdef MULTIBYTE
#include "mb/pg_wchar.h"
#endif
/*
* Is there a rule by the given name?
*/
bool
IsDefinedRewriteRule(Oid owningRel, const char *ruleName)
{
return SearchSysCacheExists(RULERELNAME,
ObjectIdGetDatum(owningRel),
PointerGetDatum(ruleName),
0, 0);
}
/*
* makeViewRetrieveRuleName
*
* Given a view name, returns the name for the associated ON SELECT rule.
*
* XXX this is not the only place in the backend that knows about the _RET
* name-forming convention.
*/
char *
MakeRetrieveViewRuleName(const char *viewName)
{
char *buf;
int buflen,
maxlen;
buflen = strlen(viewName) + 5;
buf = palloc(buflen);
snprintf(buf, buflen, "_RET%s", viewName);
/* clip to less than NAMEDATALEN bytes, if necessary */
#ifdef MULTIBYTE
maxlen = pg_mbcliplen(buf, strlen(buf), NAMEDATALEN - 1);
#else
maxlen = NAMEDATALEN - 1;
#endif
if (maxlen < buflen)
buf[maxlen] = '\0';
return buf;
}
/*
* SetRelationRuleStatus
* Set the value of the relation's relhasrules field in pg_class;
* if the relation is becoming a view, also adjust its relkind.
*
* NOTE: caller must be holding an appropriate lock on the relation.
*
* NOTE: an important side-effect of this operation is that an SI invalidation
* message is sent out to all backends --- including me --- causing relcache
* entries to be flushed or updated with the new set of rules for the table.
* Therefore, we execute the update even if relhasrules has the right value
* already. Possible future improvement: skip the disk update and just send
* an SI message in that case.
*/
void
SetRelationRuleStatus(Oid relationId, bool relHasRules,
bool relIsBecomingView)
{
Relation relationRelation;
HeapTuple tuple;
Relation idescs[Num_pg_class_indices];
/*
* Find the tuple to update in pg_class, using syscache for the
* lookup.
*/
relationRelation = heap_openr(RelationRelationName, RowExclusiveLock);
tuple = SearchSysCacheCopy(RELOID,
ObjectIdGetDatum(relationId),
0, 0, 0);
if (!HeapTupleIsValid(tuple))
elog(ERROR, "SetRelationRuleStatus: cache lookup failed for relation %u", relationId);
/* Do the update */
((Form_pg_class) GETSTRUCT(tuple))->relhasrules = relHasRules;
if (relIsBecomingView)
((Form_pg_class) GETSTRUCT(tuple))->relkind = RELKIND_VIEW;
simple_heap_update(relationRelation, &tuple->t_self, tuple);
/* Keep the catalog indices up to date */
CatalogOpenIndices(Num_pg_class_indices, Name_pg_class_indices, idescs);
CatalogIndexInsert(idescs, Num_pg_class_indices, relationRelation, tuple);
CatalogCloseIndices(Num_pg_class_indices, idescs);
heap_freetuple(tuple);
heap_close(relationRelation, RowExclusiveLock);
}
|
