Nikitas N' Karanikolas,

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CUDL Language Semantics, Liven Up the FDB Data
Model

• Nikitas N. Karanikolas,
• Maria Nitsiou,
• Emmanuel J. Yannakoudakis
• and Christos Skourlas

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FDB framework

• We have a new database framework that supports
• dynamically evolving database environments and
  corresponding schemata, allowing storage and
  manipulation of
• variable length data,
• a variable number of fields per record,
• variable length records,
• manipulation of authority records,
• links between records and fields, and
• dynamically defined objects (relations in the
  traditional sense)
• multi-value fields
• multi-attribute fields
• a combination of the last two above
• Eliminates completely the need for reorganisation
  at both logical and internal levels
• The structure of the FDB model allows easy
  schema evolution

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FDB MODEL SCHEMA

• The improved basic schema of the proposed
  framework has the following form (note that
  primary keys are underlined)
• Languages (language_id, lang_name)
• Datatypes (datatype_id, datatype_name)
• Messages (message_id, language, message)
• Entities (frame_entity_id, title)
• Tag_attributes (entity, tag, title, occurrence,
  repetition, authority, language, datatype,
  length)
• Subfield_attributes (entity, tag, subfield,
  title, occurrence, repetition, language,
  datatype, length)

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FDB MODEL SCHEMA (CONT.)

• Catalogue (Entity, Frame_object_number,
  Frame_object_label, Temp_stamp)
• Tag_data (Entity, Frame_object, Tag, Repetition,
  Chunk, Tdata)
• Authority_links (From_entity, Auth_tag1,
  To_entity, Auth_tag2, mn_data_loc)
• Subfield_data (Entity, Frame_object, Tag,
  Tag_repetion, Subfield, Subfld_Repetition,
  Chunk,sdata)
• ONE database schema for any application
• There are no new tables for each new entity

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Metadata of an FDB database defining the project
entity
Messages
Tag_attributes
Subfield_attributes
Entities
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Metadata explained of an FDB database defining
the project entity
Datatypes
Tag_attributes
Subfield_attributes
Entities
We have inserted the value NULL in the length
attribute because in certain datatypes (such as
int, date, etc) we can not define a specific
length
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Complicated in use

• The framework is complicated and the management
  and operation of it is difficult, laborious and
  time-consuming
• It requires from the user a very good
  acquaintance of the
• proposed framework,
• the structures and organisation of it
• (metadata and data)
• the processes of the management of the elements
  that compose it.

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CUDL Language (Conceptual Universal Database
Language)

• The CUDL language uses simple statements
• to manipulate the applications that have been
  created based on the proposed FDB framework
• With CUDL the user
• will not be compelled to know in-depth all the
  details of the structure of information that are
  supported by this model
• The user conceives the data as a extension of the
  relational model with fields of variable length,
  multiple values, subfields, table in the place of
  a field value, etc

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CUDL language

• The CUDL language undertakes the management of
  the complicated structures of the FDB model
• By the use of CUDL, access in the information of
  an FDB application becomes very simple with the
  use of particularly simple statements.

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How the user conceives the structure of a project
frame (tuple)
Projects
Actions
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The language deals with

• Schema definition, to declare the structures,
  integrity constraints, and access privileges of a
  database
• Schema manipulation, to alter a schema definition
• Data manipulation, to populate a database and
  access FDB data
• Transaction management, to define and manage FDB
  transactions
• Connection management, to establish and manage
  FDB connections
• Session management, to set the attributes of an
  FDB session

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Schema and Data Manipulation Language

• We will focus on the
• Schema and Data Manipulation Language
• Both aspects of the language use variations of
  the statements
• FIND
• ALTER
• DELETE
• ADD
• to manipulate values from the
• meta-data and
• data sets
• of the model

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Find

• The most frequently used operation in data
  sources is the data retrieval operation which
  retrieves instances from a set
• The FIND statement specifies which instances to
  include in the result set and it is used to
  retrieve zero or more instances from one or more
  sets in a data source
• In specifying a FIND query, the user specifies a
  description of the desired result set,
• but he does not specify what physical operations
  must be executed to produce that result set.
• The result from the implementation of a FIND
  statement is a new virtual set that contains the
  elements that were asked by the user or the value
  NULL, if no values meet the requirements of the
  Find statement.

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Find

• Find values in the meta-data sets
• (example 1)
• Find tag_attributes when title DVD_code

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Find

• Find values in the meta-data sets
• (example 2)
• Find tag_attributes when entity customer
  and repetitionr and datatypechar

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Find

• Find values in the data sets
• (example 1)
• Find data when entity customer and tag
  cust_code

Informally this statement takes the sequence of
all customers and creates a sequence of their
cust_code. The result of typing in this query
is that a sequence of cust_CODE is printed out.
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Find

• Find values in the data sets
• (examples 2, 3, 4)
• Find data when entity videos and tag
  title
• This statement retrieves the titles of the videos
  (the projected field is title).
• Find data when entity videos and tag
  title frame
• Notice that by adding the keyword frame we take
  all the data of all the tags for every frame that
  meets the user requirements. The condition and
  tagtitle is unnecessary and can be excluded
  from the statement.
• Find data when entity videos and tag
  title restr data like M and tag year
  restr data 2003
• We have to mention that the conditions can be
  composed by a where part and a restriction part.
  For example the condition and tag title restr
  data like M has a where part tag title and
  a restriction part restr data like M. The
  fields that take place in the where part of the
  conditions also participate in the results
  (projected fields).

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Add

• The ADD statement specifies which values to
  include in a database set
• In specifying an ADD query, the user specifies
  the desired values to be inserted in a specific
  desired set,
• but he does not specify what physical operations
  must be executed for the insertion
• The result from the implementation of an ADD
  statement is
• a new augmented set that contains also the new
  elements that were asked by the user or
• merely the old set if the new values can not de
  added

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Add

• Addition of meta-data
• Let us for example assume that there is no tag
  language for the entity videos. The statement
  in the CUDL language
• Add tag_attributes entity videos title
  language
• will result in the tuple shown in Table 5 stored
  in the tag attributes set.

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Add

• Addition of data
• (example of the creation and population of a
  whole frame)
• Add data set 'title' ' A Movie ' when entity
  videos new frame
• Add data set 'year' '2007' when entity
  videos and tag title restr data A
  Movie
• Add data set actor1 Al Patsino when
  entity videos and tag title restr data
  A Movie
• Add data set actor2 Robert DeNiro when
  entity videos and subfield actor1 restr
  data Al Patsino
• Note that by adding the key-phrase new frame
  the data are inserted in a new frame. Otherwise
  if those keywords are omitted the data are
  inserted in an already existing frame that the
  user must specify by adding the keywords when
  tdata ltsome valuegt. If the user does not use
  the specification referred above then a suitable
  message is presented to him and the statement is
  not executed.

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Delete

• The DELETE statement specifies which values to
  exclude from a database set
• In specifying a DELETE query, the user specifies
  the desired values to be removed from a specific
  set,
• but he does not specify what physical operations
  must be executed for the removal
• The result from the implementation of a DELETE
  statement is
• a new set that does not contain the elements
  that the user asked to be removed or
• the old set if the values can not de removed

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Delete

• Deletion from a metadata set
• Delete tag_attributes when entity videos
  and title actors
• This will result in the deletion from the set
  tag_attributes of all the values that correspond
  to the combination of the entity videos and the
  tag (title) actors.
• In the simplified relational view that the user
  conceives these statements remove the field
  actors from the table videos.
• The deletion will only occur under the condition
  that there do not exist data for the actors tag
  and also the specified tag does not participate
  in any authority link (set authority_links).

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Delete

• Deletion from a data set
• Delete data category when entity videos
  and tag DVD_code restr tdata Vid01
• Delete data whole_frame when entity 'videos'
  and tag 'DVD code' restr data 'Vid01
• We have to mention that the set catalogue is
  affected as well, by this delete statement. As
  the set catalogue is used to keep the values of
  the entity and each frame for this entity that
  the set tag_data contains, since a whole frame
  from the set tag_data was erased the
  corresponding entity and frame from the set
  catalogue should be erased too.

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Alter

• The ALTER statement specifies which values to
  alter in a database set
• In specifying a ALTER query, the user specifies
  the desired values to be modified from a specific
  set,
• but he does not specify what physical operations
  must be executed for the modification
• The result from the implementation of an ALTER
  statement is
• a new set that does not contain the altered
  elements that the user asked for or
• the old set if the values can not de modified

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Alter

• Alter values in a metadata set
• Alter tag_attributes set occurrence M' when
  entity customer and title address

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Alter

• Alter values in a data set
• Alter data set title Movie1 when entity
  videos and tag DVD_code restr data Vid01
  and tag title restr data A Movie
• This statement modifies the data value of the tag
  title A Movie to the data value Movie1 .
  This will only occur under the condition that the
  specified tag (in the specified frame) has no tag
  repetitions under the tag title

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Conclusions

• The FDB model can form the basis for the creation
  and maintenance of dynamically evolving database
  environments
• The CUDL language
• undertakes the management of the complicated
  structures of the FDB model and the user
  experiences a simple extension of the relational
  model with the usage of very simple statements

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Thank you for your attention !!!
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