D.8. RDB$FIELDS

RDB$FIELDS stores definitions of columns and domains, both system and custom. This is where the detailed data attributes are stored for all columns.

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Note

The column RDB$FIELDS.RDB$FIELD_NAME links to RDB$RELATION_FIELDS.RDB$FIELD_SOURCE, not to RDB$RELATION_FIELDS.RDB$FIELD_NAME.

Column NameData TypeDescription

RDB$FIELD_NAME

CHAR(31)

The unique name of the domain created by the user or of the domain automatically built for the table column by the system. System-created domain names start with the RDB$ prefix

RDB$QUERY_NAME

CHAR(31)

Not used

RDB$VALIDATION_BLR

BLOB BLR

The binary language representation (BLR) of the SQL expression specifying the check of the CHECK value in the domain

RDB$VALIDATION_SOURCE

BLOB TEXT

The original source text in the SQL language specifying the check of the CHECK value

RDB$COMPUTED_BLR

BLOB BLR

The binary language representation (BLR) of the SQL expression the database server uses for evaluation when accessing a COMPUTED BY column

RDB$COMPUTED_SOURCE

BLOB TEXT

The original source text of the expression that defines a COMPUTED BY column

RDB$DEFAULT_VALUE

BLOB BLR

The default value, if any, for the field or domain, in binary language representation (BLR)

RDB$DEFAULT_SOURCE

BLOB TEXT

The default value in the source code, as an SQL constant or expression

RDB$FIELD_LENGTH

SMALLINT

Column size in bytes. FLOAT, DATE, TIME, INTEGER occupy 4 bytes. DOUBLE PRECISION, BIGINT, TIMESTAMP and BLOB identifier occupy 8 bytes. For the CHAR and VARCHAR data types, the column stores the maximum number of bytes specified when a string domain (column) is defined

RDB$FIELD_SCALE

SMALLINT

The negative number that specifies the scale for DECIMAL and NUMERIC columns — the number of digits after the decimal point

RDB$FIELD_TYPE

SMALLINT

Data type code for the column:

7 - SMALLINT `8 - INTEGER `10 - FLOAT 12 - DATE 13 - TIME 14 - CHAR 16 - BIGINT 27 - DOUBLE PRECISION 35 - TIMESTAMP 37 - VARCHAR 261 - BLOB

Codes for DECIMAL and NUMERIC are the same as for the integer types used to store them

RDB$FIELD_SUB_TYPE

SMALLINT

Specifies the subtype for the BLOB data type:

0 - untyped (binary) 1 - text 2 - BLR 3 - access control list 4 - reserved for future use 5 - encoded table metadata description 6 - for storing the details of a cross-database transaction that ends abnormally < 0 - user-defined

Specifies for the CHAR data type:

0 - untyped data 1 - fixed binary data

Specifies the particular data type for the integer data types (SMALLINT, INTEGER, BIGINT) and for fixed-point numbers (NUMERIC, DECIMAL):

0 or NULL - the data type matches the value in the RDB$FIELD_TYPE field 1 - NUMERIC 2 - DECIMAL

RDB$MISSING_VALUE

BLOB BLR

Not used

RDB$MISSING_SOURCE

BLOB TEXT

Not used

RDB$DESCRIPTION

BLOB TEXT

Any domain (table column) comment text

RDB$SYSTEM_FLAG

SMALLINT

Flag: the value of 1 means the domain is automatically created by the system, the value of 0 means that the domain is defined by the user

RDB$QUERY_HEADER

BLOB TEXT

Not used

RDB$SEGMENT_LENGTH

SMALLINT

Specifies the length of the BLOB buffer in bytes for BLOB columns. Stores NULL for all other data types

RDB$EDIT_STRING

VARCHAR(127)

Not used

RDB$EXTERNAL_LENGTH

SMALLINT

The length of the column in bytes if it belongs to an external table. Always NULL for regular tables

RDB$EXTERNAL_SCALE

SMALLINT

The scale factor of an integer-type field in an external table; represents the power of 10 by which the integer is multiplied

RDB$EXTERNAL_TYPE

SMALLINT

The data type of the field as it is represented in an external table:

7 - SMALLINT 8 - INTEGER 10 - FLOAT 12 - DATE 13 - TIME 14 - CHAR 16 - BIGINT 27 - DOUBLE PRECISION 35 - TIMESTAMP 37 - VARCHAR 261 - BLOB

RDB$DIMENSIONS

SMALLINT

Defines the number of dimensions in an array if the column is defined as an array. Always NULL for columns that are not arrays

RDB$NULL_FLAG

SMALLINT

Nullable state of the domain:

NULL

nullable

1

not nullable (NOT NULL)

RDB$CHARACTER_LENGTH

SMALLINT

The length of CHAR or VARCHAR columns in characters (not in bytes)

RDB$COLLATION_ID

SMALLINT

The identifier of the collation sequence for a character column or domain. If it is not defined, the value of the field will be 0

RDB$CHARACTER_SET_ID

SMALLINT

The identifier of the character set for a character column, BLOB TEXT column or domain

RDB$FIELD_PRECISION

SMALLINT

Specifies the total number of digits for the fixed-point numeric data type (DECIMAL and NUMERIC). The value is 0 for the integer data types, NULL is for other data types