| typname | name | | Data type name |
| typnamespace | oid | pg_namespace.oid | The OID of the namespace that contains this type
|
| typowner | oid | pg_authid.oid | Owner of the type |
| typlen | int2 | | For a fixed-size type, typlen is the number
of bytes in the internal representation of the type. But for a
variable-length type, typlen is negative.
-1 indicates a "varlena" type (one that has a length word),
-2 indicates a null-terminated C string.
|
| typbyval | bool | | typbyval determines whether internal
routines pass a value of this type by value or by reference.
typbyval had better be false if
typlen is not 1, 2, or 4 (or 8 on machines
where Datum is 8 bytes).
Variable-length types are always passed by reference. Note that
typbyval can be false even if the
length would allow pass-by-value; this is currently true for
type float4, for example
|
| typtype | char | | typtype is b for
a base type, c for a composite type (e.g., a
table's row type), d for a domain, or
p for a pseudo-type. See also
typrelid and
typbasetype
|
| typisdefined | bool | | True if the type is defined, false if this is a placeholder
entry for a not-yet-defined type. When
typisdefined is false, nothing
except the type name, namespace, and OID can be relied on
|
| typdelim | char | | Character that separates two values of this type when parsing
array input. Note that the delimiter is associated with the array
element data type, not the array data type
|
| typrelid | oid | pg_class.oid | If this is a composite type (see
typtype), then this column points to
the pg_class entry that defines the
corresponding table. (For a free-standing composite type, the
pg_class entry doesn't really represent
a table, but it is needed anyway for the type's
pg_attribute entries to link to.)
Zero for non-composite types
|
| typelem | oid | pg_type.oid | If typelem is not 0 then it
identifies another row in pg_type.
The current type can then be subscripted like an array yielding
values of type typelem. A
"true" array type is variable length
(typlen = -1),
but some fixed-length (typlen > 0) types
also have nonzero typelem, for example
name and point.
If a fixed-length type has a typelem then
its internal representation must be some number of values of the
typelem data type with no other data.
Variable-length array types have a header defined by the array
subroutines
|
| typinput | regproc | pg_proc.oid | Input conversion function (text format) |
| typoutput | regproc | pg_proc.oid | Output conversion function (text format) |
| typreceive | regproc | pg_proc.oid | Input conversion function (binary format), or 0 if none |
| typsend | regproc | pg_proc.oid | Output conversion function (binary format), or 0 if none |
| typanalyze | regproc | pg_proc.oid | Custom ANALYZE function, or 0 to use the standard function |
| typalign | char | |
typalign is the alignment required
when storing a value of this type. It applies to storage on
disk as well as most representations of the value inside
PostgreSQL.
When multiple values are stored consecutively, such
as in the representation of a complete row on disk, padding is
inserted before a datum of this type so that it begins on the
specified boundary. The alignment reference is the beginning
of the first datum in the sequence.
Possible values are:
c = char alignment, i.e., no alignment needed. s = short alignment (2 bytes on most machines). i = int alignment (4 bytes on most machines). d = double alignment (8 bytes on many machines, but by no means all).
Note: For types used in system tables, it is critical that the size
and alignment defined in pg_type
agree with the way that the compiler will lay out the column in
a structure representing a table row.
|
| typstorage | char | | typstorage tells for varlena
types (those with typlen = -1) if
the type is prepared for toasting and what the default strategy
for attributes of this type should be.
Possible values are
p: Value must always be stored plain. e: Value can be stored in a "secondary"
relation (if relation has one, see
pg_class.reltoastrelid).
m: Value can be stored compressed inline. x: Value can be stored compressed inline or stored in "secondary" storage.
Note that m columns can also be moved out to secondary
storage, but only as a last resort (e and x columns are
moved first).
|
| typnotnull | bool | | typnotnull represents a not-null
constraint on a type. Used for domains only
|
| typbasetype | oid | pg_type.oid | If this is a domain (see typtype), then
typbasetype identifies the type that this
one is based on. Zero if this type is not a domain
|
| typtypmod | int4 | | Domains use typtypmod to record the typmod
to be applied to their base type (-1 if base type does not use a
typmod). -1 if this type is not a domain
|
| typndims | int4 | | typndims is the number of array dimensions
for a domain that is an array (that is, typbasetype is an array type;
the domain's typelem will match the base type's typelem).
Zero for types other than array domains
|
| typdefaultbin | text | | If typdefaultbin is not null, it is the nodeToString()
representation of a default expression for the type. This is
only used for domains
|
| typdefault | text | | typdefault is null if the type has no associated
default value. If typdefaultbin is not null,
typdefault must contain a human-readable version of the
default expression represented by typdefaultbin. If
typdefaultbin is null and typdefault is
not, then typdefault is the external representation of
the type's default value, which may be fed to the type's input
converter to produce a constant
|
Personal Loan | Free Advertising | Web Advertising | Internet Advertising | Mortgage