File Definition Item
A file definition item, located in an account's MD, defines the location and characteristics of a file. It points to the file dictionary, giving system information in attribute 2, which specifies the location of the file in the host system, and file creation parameters in attribute 3. It also defines retrieval and update lock codes in attributes 5 and 6, and English formatting characteristics in attributes 7 to 10.
Item format
| Attribute | Description |
|---|---|
| Item-id | File name. |
| 001 |
D {I} {L||R} {C} {T} {X|Y} where: D Marks a Definition Item. I Specifies that the file contains case-insensitive item-ids. L Specifies that the file is to be logged by Transaction Logging. This is the default setting when a file is created. R Specifies that the file is not logged by Transaction Logging, but that its data will be recovered during the automatic recovery of a database configured for Rapid Recovery. C Specifies that the dictionary or file contains or has contained compiled DataBasic programs. Added when you compile a program. T Specifies that the file does not take part in transactions. As a result, if a transaction is aborted, the changes will not be rolled back. It is recommended that this code is used for application log files. X Specifies that the file will be excluded from logical saves. Y Specifies that the SAVE command will save only D-pointers (data level descriptors). When restored the file will be empty. Notes:
|
| 002 |
On a Partition Database: start, modulo, id where: startis the logical block number of the start of file dictionary. modulois the modulo of the file dictionary. idis the reuse identifier. OR, on a Filestore Database: The UNIX path name of the file dictionary. OR, for a file on a Foreign Database: n;TableName where: nis a number indicating which version of the access method created the file. TableName
OR, for a directory view or special file: Empty. |
| 003 |
File creation parameters. The first character specifies the file type (see below) and the second is always '2' (file dictionary). Subsequent characters depend on the file type. For a normal file on the Local Database: File creation parameters - B2 modulo,1 (for example, where: B Specifies a normal Reality file. modulo The modulo of the dictionary. OR, for a file on a Foreign Database: F2 dsn, {userId}, {password} where: FSpecifies a file on a foreign database. dsnThe ODBC Data Source Name for the foreign database. The Data Source Name may itself include a user-id and password. For information on how to set up Data Source Names, refer to Setting-up the SQL/ODBC Data Source in SQL for Reality. userIdThe user-id for connecting to the foreign database. passwordThe password associated with userId (encrypted). |
| 004 | File trigger information. This is a subvalued list of trigger subroutine names in the order PRE-WRITE, POST-WRITE, PRE-DELETE, POST-DELETE. |
| 005 | Optional. Retrieval lock code(s). |
| 006 | Optional. Update lock code(s). |
| 007 | Optional. Conversion codes for English to display item-ids. |
| 008 | Optional V (sublist) code for English. |
| 009 |
Mandatory. Contains a code specifying the type of alignment to be used by English. Must be one of the following: LLeft aligned. RRight aligned. TText aligned. Text wraps at word boundaries. UUnlimited. Note For more details, refer to the topic Data Definition Item. |
| 010 | Maximum width of item-id column. Defaults to 10 when the file dictionary is created. |
| 011 | Not used and reserved. |
| 012 | Null. |
| 013 |
Optional. Reallocation parameters. At the next restore from a FILE-SAVE, the file dictionary is allocated the new modulo and separation parameters specified here. The format of this specification is (modulo, separation), where modulo is the new modulo expressed as a decimal integer (separation is always 1 on the current version of Reality). |
| 014 - 020 | Reserved. |