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
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
|
/*-------------------------------------------------------------------------
*
* pg_attribute.h
* definition of the "attribute" system catalog (pg_attribute)
*
* The initial contents of pg_attribute are generated at compile time by
* genbki.pl, so there is no pg_attribute.dat file. Only "bootstrapped"
* relations need be included.
*
*
* Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/catalog/pg_attribute.h
*
* NOTES
* The Catalog.pm module reads this file and derives schema
* information.
*
*-------------------------------------------------------------------------
*/
#ifndef PG_ATTRIBUTE_H
#define PG_ATTRIBUTE_H
#include "catalog/genbki.h"
#include "catalog/pg_attribute_d.h"
/* ----------------
* pg_attribute definition. cpp turns this into
* typedef struct FormData_pg_attribute
*
* If you change the following, make sure you change the structs for
* system attributes in catalog/heap.c also.
* You may need to change catalog/genbki.pl as well.
* ----------------
*/
CATALOG(pg_attribute,1249,AttributeRelationId) BKI_BOOTSTRAP BKI_ROWTYPE_OID(75,AttributeRelation_Rowtype_Id) BKI_SCHEMA_MACRO
{
Oid attrelid BKI_LOOKUP(pg_class); /* OID of relation containing
* this attribute */
NameData attname; /* name of attribute */
/*
* atttypid is the OID of the instance in Catalog Class pg_type that
* defines the data type of this attribute (e.g. int4). Information in
* that instance is redundant with the attlen, attbyval, and attalign
* attributes of this instance, so they had better match or Postgres will
* fail. In an entry for a dropped column, this field is set to zero
* since the pg_type entry may no longer exist; but we rely on attlen,
* attbyval, and attalign to still tell us how large the values in the
* table are.
*/
Oid atttypid BKI_LOOKUP_OPT(pg_type);
/*
* attlen is a copy of the typlen field from pg_type for this attribute.
* See atttypid comments above.
*/
int16 attlen;
/*
* attnum is the "attribute number" for the attribute: A value that
* uniquely identifies this attribute within its class. For user
* attributes, Attribute numbers are greater than 0 and not greater than
* the number of attributes in the class. I.e. if the Class pg_class says
* that Class XYZ has 10 attributes, then the user attribute numbers in
* Class pg_attribute must be 1-10.
*
* System attributes have attribute numbers less than 0 that are unique
* within the class, but not constrained to any particular range.
*
* Note that (attnum - 1) is often used as the index to an array.
*/
int16 attnum;
/*
* fastgetattr() uses attcacheoff to cache byte offsets of attributes in
* heap tuples. The value actually stored in pg_attribute (-1) indicates
* no cached value. But when we copy these tuples into a tuple
* descriptor, we may then update attcacheoff in the copies. This speeds
* up the attribute walking process.
*/
int32 attcacheoff BKI_DEFAULT(-1);
/*
* atttypmod records type-specific data supplied at table creation time
* (for example, the max length of a varchar field). It is passed to
* type-specific input and output functions as the third argument. The
* value will generally be -1 for types that do not need typmod.
*/
int32 atttypmod BKI_DEFAULT(-1);
/*
* attndims is the declared number of dimensions, if an array type,
* otherwise zero.
*/
int16 attndims;
/*
* attbyval is a copy of the typbyval field from pg_type for this
* attribute. See atttypid comments above.
*/
bool attbyval;
/*
* attalign is a copy of the typalign field from pg_type for this
* attribute. See atttypid comments above.
*/
char attalign;
/*----------
* attstorage tells for VARLENA attributes, what the heap access
* methods can do to it if a given tuple doesn't fit into a page.
* Possible values are as for pg_type.typstorage (see TYPSTORAGE macros).
*----------
*/
char attstorage;
/*
* attcompression sets the current compression method of the attribute.
* Typically this is InvalidCompressionMethod ('\0') to specify use of the
* current default setting (see default_toast_compression). Otherwise,
* 'p' selects pglz compression, while 'l' selects LZ4 compression.
* However, this field is ignored whenever attstorage does not allow
* compression.
*/
char attcompression BKI_DEFAULT('\0');
/* This flag represents the "NOT NULL" constraint */
bool attnotnull;
/* Has DEFAULT value or not */
bool atthasdef BKI_DEFAULT(f);
/* Has a missing value or not */
bool atthasmissing BKI_DEFAULT(f);
/* One of the ATTRIBUTE_IDENTITY_* constants below, or '\0' */
char attidentity BKI_DEFAULT('\0');
/* One of the ATTRIBUTE_GENERATED_* constants below, or '\0' */
char attgenerated BKI_DEFAULT('\0');
/* Is dropped (ie, logically invisible) or not */
bool attisdropped BKI_DEFAULT(f);
/*
* This flag specifies whether this column has ever had a local
* definition. It is set for normal non-inherited columns, but also for
* columns that are inherited from parents if also explicitly listed in
* CREATE TABLE INHERITS. It is also set when inheritance is removed from
* a table with ALTER TABLE NO INHERIT. If the flag is set, the column is
* not dropped by a parent's DROP COLUMN even if this causes the column's
* attinhcount to become zero.
*/
bool attislocal BKI_DEFAULT(t);
/* Number of times inherited from direct parent relation(s) */
int16 attinhcount BKI_DEFAULT(0);
/*
* attstattarget is the target number of statistics datapoints to collect
* during VACUUM ANALYZE of this column. A zero here indicates that we do
* not wish to collect any stats about this column. A "-1" here indicates
* that no value has been explicitly set for this column, so ANALYZE
* should use the default setting.
*
* int16 is sufficient because the max value is currently 10000.
*/
int16 attstattarget BKI_DEFAULT(-1);
/* attribute's collation, if any */
Oid attcollation BKI_LOOKUP_OPT(pg_collation);
#ifdef CATALOG_VARLEN /* variable-length fields start here */
/* NOTE: The following fields are not present in tuple descriptors. */
/* Column-level access permissions */
aclitem attacl[1] BKI_DEFAULT(_null_);
/* Column-level options */
text attoptions[1] BKI_DEFAULT(_null_);
/* Column-level FDW options */
text attfdwoptions[1] BKI_DEFAULT(_null_);
/*
* Missing value for added columns. This is a one element array which lets
* us store a value of the attribute type here.
*/
anyarray attmissingval BKI_DEFAULT(_null_);
#endif
} FormData_pg_attribute;
/*
* ATTRIBUTE_FIXED_PART_SIZE is the size of the fixed-layout,
* guaranteed-not-null part of a pg_attribute row. This is in fact as much
* of the row as gets copied into tuple descriptors, so don't expect you
* can access the variable-length fields except in a real tuple!
*/
#define ATTRIBUTE_FIXED_PART_SIZE \
(offsetof(FormData_pg_attribute,attcollation) + sizeof(Oid))
/* ----------------
* Form_pg_attribute corresponds to a pointer to a tuple with
* the format of pg_attribute relation.
* ----------------
*/
typedef FormData_pg_attribute *Form_pg_attribute;
DECLARE_UNIQUE_INDEX(pg_attribute_relid_attnam_index, 2658, AttributeRelidNameIndexId, on pg_attribute using btree(attrelid oid_ops, attname name_ops));
DECLARE_UNIQUE_INDEX_PKEY(pg_attribute_relid_attnum_index, 2659, AttributeRelidNumIndexId, on pg_attribute using btree(attrelid oid_ops, attnum int2_ops));
#ifdef EXPOSE_TO_CLIENT_CODE
#define ATTRIBUTE_IDENTITY_ALWAYS 'a'
#define ATTRIBUTE_IDENTITY_BY_DEFAULT 'd'
#define ATTRIBUTE_GENERATED_STORED 's'
#endif /* EXPOSE_TO_CLIENT_CODE */
#endif /* PG_ATTRIBUTE_H */
|
