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Diffstat (limited to 'src/include/catalog/pg_attribute.h')
| -rw-r--r-- | src/include/catalog/pg_attribute.h | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/src/include/catalog/pg_attribute.h b/src/include/catalog/pg_attribute.h new file mode 100644 index 0000000..a4cc80a --- /dev/null +++ b/src/include/catalog/pg_attribute.h @@ -0,0 +1,204 @@ +/*------------------------------------------------------------------------- + * + * 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) 1996-2020, 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; /* 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. + */ + Oid atttypid; + + /* + * 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. + */ + int32 attstattarget BKI_DEFAULT(-1); + + /* + * 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; + + /* + * attndims is the declared number of dimensions, if an array type, + * otherwise zero. + */ + int32 attndims; + + /* + * 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); + + /* + * attbyval is a copy of the typbyval field from pg_type for this + * attribute. See atttypid comments above. + */ + bool attbyval; + + /*---------- + * 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; + + /* + * attalign is a copy of the typalign field from pg_type for this + * attribute. See atttypid comments above. + */ + char attalign; + + /* 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) */ + int32 attinhcount BKI_DEFAULT(0); + + /* attribute's collation */ + Oid attcollation; + +#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 fields beyond attcollation 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; + +#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 */ |