Database URL - Revision history

Gray at 23:18, 9 November 2011

2011-11-09T23:18:58Z

Gray at 23:18, 9 November 2011

2011-11-09T23:18:31Z

Gray at 07:05, 27 October 2011

2011-10-27T07:05:35Z

Gray at 22:27, 26 October 2011

2011-10-26T22:27:01Z

Gray: Created page with "A database URL describes a hash database for use with the libmu_dbm library. In its full form it has the following syntax: scheme://dbfile;params Of all its parts, only ..."

2011-10-26T22:25:54Z

Created page with "A database URL describes a hash database for use with the libmu_dbm library. In its full form it has the following syntax: scheme://dbfile;params Of all its parts, only ..."

New page

A database URL describes a hash database for use with the [[libmu_dbm]] library. In its full form it has the following syntax:

scheme://dbfile;params

Of all its parts, only <tt>dbfile</tt> is required. It specifies the file name (either absolute or relative) of the database file. If the underlying implementation stores the database in two files (as it is the case with NBDM), <tt>dbfile</tt> will be used as a base name for those files (i.e. the suffixes <tt>.pag</tt> and <tt>.dir</tt> will be appended to it).

If <tt>scheme</tt> is specified, it declares the DBM implementation to use. Valid values are:

;gdbm
[http://www.gnu.org/software/gdbm GNU DBM]
;bdb
[http://www.oracle.com/technetwork/database/berkeleydb/overview/index.html Berkeley DB]
;ndbm
:Traditional [http://en.wikipedia.org/wiki/Ndbm NDBM]
;tc
:[http://fallabs.com/tokyocabinet/ Tokyo Cabinet]
{{Note|The latter is not yet implemented}}

In the absense of <tt>scheme</tt> the default database implementation will be used. This is the first one shown in the list of DBMs when configuring the package. For example, if <tt>configure</tt> showed:

Use DBM ....................... GDBM,Berkeley DB v. 4,NDBM

then <tt>gdbm://</tt> will be assumed by default.

The optional <tt>params</tt> is a list of [[File_Safety_Checks#safety-checks|safety check criteria]], separated by semicolons. The <tt>default</tt> keyword is synonymous with <tt>all</tt>.
In addition to the usual safety criteria, the following parameter can be used:

;+owner
:Enable the [[File_Safety_Functions#MU_FILE_SAFETY|MU_FILE_SAFETY_OWNER_MISMATCH]] check. Assume that the database files must be owned by the real UID of the current user.
;owner=''user''
:Enable that check and set the user which must own the database file. The ''user'' argument is either a valid user name or UID.
;-owner
:Disable that check.

Examples:

/etc/apop.db
bdb:///etc/apop.db
bdb:///etc/apop.db;owner=root;all;-grdfil

@@ Line 8: / Line 8: @@
 ;gdbm
-[http://www.gnu.org/software/gdbm GNU DBM]
+:[http://www.gnu.org/software/gdbm GNU DBM]
 ;bdb
-[http://www.oracle.com/technetwork/database/berkeleydb/overview/index.html Berkeley DB]
+:[http://www.oracle.com/technetwork/database/berkeleydb/overview/index.html Berkeley DB]
 ;ndbm
 :Traditional [http://en.wikipedia.org/wiki/Ndbm NDBM]

@@ Line 15: / Line 15: @@
 ;tc
 :[http://fallabs.com/tokyocabinet/ Tokyo Cabinet]
-{{Note|The latter is not yet implemented}}
+;kc
 In the absense of <tt>scheme</tt> the default database implementation will be used.  This is the first one shown in the list of DBMs when configuring the package.  For example, if <tt>configure</tt> showed:

@@ Line 23: / Line 23: @@
 then <tt>gdbm://</tt> will be assumed by default.
 The optional <tt>params</tt> is a list of [[File_Safety_Checks#safety-checks|safety check criteria]], separated by semicolons.  The <tt>default</tt> keyword is synonymous with <tt>all</tt>.
 In addition to the usual safety criteria, the following parameter can be used:

@@ Line 1: / Line 1: @@
-A database URL describes a hash database for use with the [[libmu_dbm]] library.  In its full form it has the following syntax:
+A database [[URL]] describes a hash database for use with the [[libmu_dbm]] library.  In its full form it has the following syntax:
    scheme://dbfile;params
@@ Line 38: / Line 38: @@
    bdb:///etc/apop.db
    bdb:///etc/apop.db;owner=root;all;-grdfil