Major change
[u/philim/db2osl_thesis.git] / program_functionality.tex
3As described in the \hyperref[intro]{introduction} of this thesis,
4the \myprog{} software is
5a program automatically deriving an OBDA specification
6from a relational database schema,
c31df1ed 7which then can be used by other tools to drive the actual bootstrapping process.
002fa020 8Its functionality is described in the following section,
62fe6284 9leaving out self-evident features, and is then listed completely
c31df1ed 10in the section after that.
002fa020 11How this functionality is exposed to users is described in section \fullref{interface}.
12The bootstrapping process as the core functionality of the software is described in
13section \fullref{bootstrapping}.
002fa020 14TODO: reference to OBDA topics
c31df1ed 15
002fa020 16\subsection{Function description}
17The database schema is retrieved by connecting to an \name{SQL} database
18and querying its schema information.
002fa020 19Parsing \name{SQL} scripts or \name{SQL} dumps currently is not supported.
20%Naturally, authentication on the \name{SQL} server is supported, also by
21%interactively querying for passwords while hiding the typed input.
22The databases to derive information from can be specified by regular expressions,
23while there are also options to use other databases than specified or even
24other database servers, taken from a list of hard-coded strings.
25While these features may not seem to carry real benefit at the first glance,
26they proved to be useful for testing purposes, especially since the retrieval of a
27database schema can take some time TODO (see section \fullref{stats}).
28For the same purpose, \myprog{} allows the processing of a hard-coded example database schema.
30In addition to \osl{} output, a low-level output format containing information on all fields of
31the underlying objects is supported, which is useful for debugging
32(however, this feature has to be enabled via one slight change in the source code).
33To allow for some customization, the insertion of an own \osl{} header is supported
34(for more information on the \osl{} header, see the specification of the \osl{} language
002fa020 35in section \ref{osl_spec}).
36If the standard \osl{} header is used, it is by default loaded from a hard-coded copy,
37so bootstrapping information from a database server running locally or from the hard-coded
38example schema requires no Internet connection
39(simply inserting the \code{owl:imports} statement of course would not anyway,
40but the generated underlying ontology is always checked for consistency with the
41\osl{} header to prevent the generation of invalid output).
43The \myprog{} software can be used both in an interactive and in a non-interactive mode,
44while skipping a database or a database server or aborting the entire bootstrapping process
45is possible in either mode.
46Multiple database servers can be specified for a bootstrapping operation,
47which then are checked in order for a matching database,
48allowing to make use of mirrors or fallback servers.
49Additionally, multiple bootstrapping operations can be specified to be performed in sequence
50with one invocation of \myprog{}, while all features and settings previously described
51are enabled, disabled or set per operation.
52Finally, a help text can be displayed which describes the usage of \myprog{} including the
53description of all command-line arguments.
002fa020 55\subsection{Function summary}
56The functionality of the \myprog{} software can be summarized as follows:
59 \item Bootstrap one or more OBDA specifications from a database schema
60 by connecting to an \name{SQL} database server
61 \item Specify a custom port, login and password for the database server
62 \item Ask for passwords interactively (before starting any bootstrapping
63 operation), hide them if desired
64 \item Specify database names by regular expressions
65 \item Process an arbitrary database if the specified database
66 could not be found or unconditionally
67 \item Connect to a database server containing example databases
68 without having to specify any further details
69 \item Process a hard-coded example database schema
70 without having to specify any further details
71 \item Use the \osl{} format described in section \fullref{osl}
72 or a detailed low-level format for output
73 (the latter is for debugging purposes and has to be enabled
74 in the source code)
75 \item Write to standard output or to a file
76 \item Insert a custom \osl{} header
77 (see the specification of the OBDA Specification Language (\osl{})
002fa020 78 in section \ref{osl_spec} for details)
79 \item Consistency check against a custom \osl{} header
80 \item Consistency check against the standard \osl{} header without internet connection
81 \item Act interactively or non-interactively
82 \item Skip currently retrieved database (and try next on server),
83 skip current server or abort the overall process at any time, even in
84 non-interactive mode
85 \item Define multiple database servers to check in order for the specified database
86 \item Specify multiple bootstrapping operations to perform in order
87 \item Configure the features described in the above notes
88 per bootstrapping operation
89 \item Display a help text describing the usage of \myprog{},
90 including the description of all command-line arguments