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queryenvironment.h
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1 /*-------------------------------------------------------------------------
2  *
3  * queryenvironment.h
4  * Access to functions to mutate the query environment and retrieve the
5  * actual data related to entries (if any).
6  *
7  * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
8  * Portions Copyright (c) 1994, Regents of the University of California
9  *
10  * src/include/utils/queryenvironment.h
11  *
12  *-------------------------------------------------------------------------
13  */
14 #ifndef QUERYENVIRONMENT_H
15 #define QUERYENVIRONMENT_H
16 
17 #include "access/tupdesc.h"
18 
19 
21 {
22  ENR_NAMED_TUPLESTORE /* named tuplestore relation; e.g., deltas */
24 
25 /*
26  * Some ephemeral named relations must match some relation (e.g., trigger
27  * transition tables), so to properly handle cached plans and DDL, we should
28  * carry the OID of that relation. In other cases an ENR might be independent
29  * of any relation which is stored in the system catalogs, so we need to be
30  * able to directly store the TupleDesc. We never need both.
31  */
33 {
34  char *name; /* name used to identify the relation */
35 
36  /* only one of the next two fields should be used */
37  Oid reliddesc; /* oid of relation to get tupdesc */
38  TupleDesc tupdesc; /* description of result rows */
39 
40  EphemeralNameRelationType enrtype; /* to identify type of relation */
41  double enrtuples; /* estimated number of tuples */
43 
45 
46 /*
47  * Ephemeral Named Relation data; used for parsing named relations not in the
48  * catalog, like transition tables in AFTER triggers.
49  */
51 {
53  void *reldata; /* structure for execution-time access to data */
55 
57 
58 /*
59  * This is an opaque structure outside of queryenvironment.c itself. The
60  * intention is to be able to change the implementation or add new context
61  * features without needing to change existing code for use of existing
62  * features.
63  */
65 
66 
67 extern QueryEnvironment *create_queryEnv(void);
68 extern EphemeralNamedRelationMetadata get_visible_ENR_metadata(QueryEnvironment *queryEnv, const char *refname);
69 extern void register_ENR(QueryEnvironment *queryEnv, EphemeralNamedRelation enr);
70 extern void unregister_ENR(QueryEnvironment *queryEnv, const char *name);
71 extern EphemeralNamedRelation get_ENR(QueryEnvironment *queryEnv, const char *name);
73 
74 #endif /* QUERYENVIRONMENT_H */
EphemeralNamedRelationMetadataData md
EphemeralNamedRelationMetadataData * EphemeralNamedRelationMetadata
void register_ENR(QueryEnvironment *queryEnv, EphemeralNamedRelation enr)
EphemeralNamedRelationMetadata get_visible_ENR_metadata(QueryEnvironment *queryEnv, const char *refname)
void unregister_ENR(QueryEnvironment *queryEnv, const char *name)
unsigned int Oid
Definition: postgres_ext.h:31
QueryEnvironment * create_queryEnv(void)
struct EphemeralNamedRelationData EphemeralNamedRelationData
struct EphemeralNamedRelationMetadataData EphemeralNamedRelationMetadataData
EphemeralNameRelationType
EphemeralNamedRelationData * EphemeralNamedRelation
TupleDesc ENRMetadataGetTupDesc(EphemeralNamedRelationMetadata enrmd)
EphemeralNamedRelation get_ENR(QueryEnvironment *queryEnv, const char *name)
EphemeralNameRelationType enrtype