• Antelope Release 5.10 Linux CentOS release 7.6.1810 (Core) 3.10.0 2020-05-12

 

NAME

dbdescriptor - Datascope database descriptor files

DESCRIPTION

Datascope databases typically have a descriptor file, which provides some of the important parameters about the database. In particular, a descriptor file specifies the schema used for the database, and the possible path names for tables of the database. There are two formats for the descriptor file: the original format with two lines, and a newer parameter file format which may contain information about locking and id servers.

Original Descriptor File

The original descriptor file has two lines. The first line specifies the schema, the second the database path.

In Antelope releases up to and including 5.2, the schema line could also consist of a list of schemas, with the names separated by colons. This usage is no longer permitted. However, similar capabilities are possible using schema extension directories and/or the SCHEMA_DIR environment variable.

New Parameter file format

A parameter file descriptor file should begin with a pound sign (#) in the first column of the first line, to distinguish it from the original format. A paramater file format descriptor file may contain the same information as the original format, but may also contain information about any locking mechanism to be used for this database (see DBLOCKS(5)), and any id server (see DBIDSERVER(5)). The following keywords may be present in this file:

EXAMPLE

Original descriptor file

For example, a database file might look like:

% cat 1987177
css3.0
/slick3/data/{nrdc}:/wfdisc/nrdc/{master}
% 

This database combines the css3.0 and lpevt schemas.

Its tables may either be found

Only the first table found is used. So if there's no file 1987177.wfdisc, but a file /slick3/data/nrdc.wfdisc and a file /wfdisc/nrdc/master.wfdisc, the file /slick3/data/nrdc.wfdisc is used as the wfdisc table.

New Parameter file descriptor file

The new descriptor file format allows specifying the setting for dblocks and dbidserver, in addition to the schema and dbpath.

% cat newdescriptor
#  This is a descriptor file
schema          css3.0
dbpath          /slick3/data/{nrdc}:/wfdisc/nrdc/{master}
dblocks         nfs
dbidserver      castle

When switching to using a central idserver, it's important to initially synchronize ids with the server, using dbfixids(1).

SEE ALSO

dbintro(3)
dbschema(5)
dbfixids(1)

AUTHOR

Daniel Quinlan
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