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<?xml version="1.0" encoding="UTF-8"?>
<record>
<header> ... (compare notes about the record header)</header>
<metadata>
<dc xmlns="http://www.openarchives.org/OAI/2.0/oai_dc/"
xmlns:dc="http://purl.org/dc/elements/1.1/">
<identifier>ID2</identifier>
<description> Usage Event Data for Server ... from ... until ... </description>
</dc>
</metadata>
</record>
<code}
\\
|
Also,
...
the
...
choice
...
of
...
identifiers
...
imposes
...
problems:
...
According
...
to
...
the
...
OAI-PMH
...
specification,
...
the
...
identifier
...
within
...
the
...
DC
...
metadata
...
set
...
must
...
link
...
to
...
the
...
described
...
document.
...
When
...
understood
...
as
...
being
...
metadata,
...
the
...
data
...
contained
...
in
...
one
...
<contextobject>
...
or
...
in
...
a
...
<context-objects>
...
aggregation
...
is
...
best
...
described
...
as
...
being
...
metadata
...
of
...
the
...
usage
...
events
...
in
...
a
...
given
...
time
...
frame.
...
Those
...
usage
...
events,
...
however,
...
regularly
...
do
...
not
...
have
...
their
...
own
...
identifiers
...
yet.
...
So
...
in
...
order
...
to
...
comply
...
with
...
DC
...
requirements,
...
too,
...
identifiers
...
have
...
to
...
be
...
generated
...
for
...
those
...
usage
...
events
...
as
...
well
...
(ID2
...
in
...
the
...
excerpt
...
above).
...
However,
...
by
...
now
...
there
...
seems
...
to
...
be
...
no
...
immediate
...
use
...
case
...
for
...
such
...
identifiers.
...
Therefore,
...
in
...
the
...
context
...
of
...
these
...
guidelines,
...
offering
...
DC
...
metadata
...
is
...
not
...
required.
...
- Usage
...
- of
...
- Sets
...
- see
...
- OAI-PMH,
...
- 2.7.2
...
- OAI-PMH
...
- optionally
...
- allows
...
- for
...
- structuring
...
- the
...
- offered
...
- data
...
- in
...
- "sets"
...
- to
...
- support
...
- selective
...
- harvesting
...
- of
...
- the
...
- data.
...
- Currently,
...
- this
...
- possibility
...
- is
...
- not
...
- further
...
- specified
...
- in
...
- these
...
- guidelines.
...
- Future
...
- refinements
...
- may
...
- use
...
- this
...
- feature,
...
- e.
...
- g.
...
- for
...
- selecting
...
- usage
...
- data
...
- for
...
- certain
...
- services.
...
- Provenance
...
- information
...
- is
...
- already
...
- included
...
- in
...
- the
...
- Context
...
- Objects.
...
- Datestamps,
...
- Granularity
...
- see
...
- OAI-PMH,
...
- 2.7.1
...
- (also
...
- compare
...
- the
...
- notes
...
- about
...
- datestamps
...
- in
...
- the
...
- OAI-PMH
...
- record
...
- header
...
- versus
...
- datestamps
...
- within
...
- the
...
- Context
...
- Objects)The
...
- OAI-PMH
...
- specification
...
- allows
...
- for
...
- either
...
- exact-to-the-second
...
- or
...
- exact-to-the-day
...
- granularity
...
- for
...
- record
...
- header
...
- datestamps.
...
- The
...
- data
...
- providers
...
- may
...
- chose
...
- one
...
- of
...
- these
...
- possibilities.
...
- The
...
- service
...
- provider
...
- will
...
- most
...
- certainly
...
- rely
...
- on
...
- overlapping
...
- harvesting,
...
- i.
...
- e.
...
- the
...
- most
...
- recent
...
- datestamp
...
- of
...
- the
...
- harvested
...
- data
...
- is
...
- used
...
- as
...
- the
...
- "from"
...
- parameter
...
- for
...
- the
...
- next
...
- OAI-PMH
...
- query.
...
- Thus,
...
- the
...
- data
...
- provider
...
- will
...
- provide
...
- some
...
- records
...
- that
...
- have
...
- been
...
- harvested
...
- before.
...
- Duplicate
...
- records
...
- are
...
- matched
...
- by
...
- their
...
- identifiers
...
- (those
...
- in
...
- the
...
- OAI-PMH
...
- record
...
- header)
...
- and
...
- are
...
- silently
...
- tossed
...
- if
...
- their
...
- datestamp
...
- is
...
- not
...
- renewed
...
- (see
...
- notes
...
- below
...
- on
...
- deletion
...
- tracking).It
...
- is
...
- strongly
...
- recommended
...
- to
...
- implement
...
- exact-to-the-second
...
- datestamps
...
- to
...
- keep
...
- redundancy
...
- of
...
- the
...
- transferred
...
- data
...
- as
...
- low
...
- as
...
- possible.
...
- Deletion
...
- tracking
...
- OAI-PMH,
...
- 2.5.1
...
- The
...
- OAI-PMH
...
- provides
...
- functionalities
...
- for
...
- the
...
- tracking
...
- of
...
- deletion
...
- of
...
- records.
...
- Compared
...
- to
...
- the
...
- classic
...
- use
...
- case
...
- of
...
- OAI-PMH
...
- (metadata
...
- of
...
- documents)
...
- the
...
- use
...
- case
...
- presented
...
- here
...
- falls
...
- into
...
- a
...
- category
...
- of
...
- data
...
- which
...
- is
...
- not
...
- subject
...
- to
...
- long-term
...
- storage.
...
- Thus,
...
- the
...
- tracking
...
- of
...
- deletion
...
- events
...
- does
...
- not
...
- seem
...
- critical
...
- since
...
- the
...
- data
...
- tracking
...
- deletions
...
- would
...
- summarize
...
- to
...
- a
...
- significant
...
- amount
...
- of
...
- data.However,
...
- the
...
- service
...
- provider
...
- will
...
- accept
...
- information
...
- about
...
- deleted
...
- records
...
- and
...
- will
...
- eventually
...
- delete
...
- the
...
- referenced
...
- information
...
- in
...
- its
...
- own
...
- data
...
- store.
...
- This
...
- way
...
- it
...
- is
...
- possible
...
- for
...
- data
...
- providers
...
- to
...
- do
...
- corrections
...
- (e.
...
- g.
...
- in
...
- case
...
- of
...
- technical
...
- problems)
...
- on
...
- wrongly
...
- issued
...
- data.It
...
- is
...
- important
...
- to
...
- note
...
- that
...
- old
...
- data
...
- which
...
- rotates
...
- out
...
- of
...
- the
...
- data
...
- offered
...
- by
...
- the
...
- data
...
- provider
...
- due
...
- to
...
- its
...
- age
...
- will
...
- not
...
- to
...
- be
...
- marked
...
- as
...
- deleted
...
- for
...
- storage
...
- reasons.
...
- This
...
- kind
...
- of
...
- data
...
- is
...
- still
...
- valid
...
- usage
...
- data,
...
- but
...
- not
...
- visible
...
- anymore.The
...
- information
...
- about
...
- whether
...
- a
...
- data
...
- provider
...
- uses
...
- deletion
...
- tracking
...
- has
...
- to
...
- be
...
- provided
...
- in
...
- the
...
- response
...
- to
...
- the
...
- "identify"
...
- OAI-PMH
...
- query
...
- within
...
- the
...
- <deletedRecords>
...
- field.
...
- Currently,
...
- the
...
- only
...
- options
...
- are
...
- "transient"
...
- (when
...
- a
...
- data
...
- provider
...
- applies
...
- or
...
- reserves
...
- the
...
- possibility
...
- for
...
- marking
...
- deleted
...
- records)
...
- or
...
- "no".The
...
- possible
...
- cases
...
- are:
...
- Incorrect
...
- data
...
- which
...
- has
...
- already
...
- been
...
- offered
...
- by
...
- the
...
- data
...
- provider
...
- shall
...
- be
...
- corrected.
...
- There
...
- are
...
- two
...
- possibilities:
...
- Re-issuing
...
- of
...
- a
...
- corrected
...
- set
...
- of
...
- data
...
- carrying
...
- the
...
- same
...
- identifier
...
- in
...
- the
...
- OAI-PMH
...
- record
...
- header
...
- as
...
- the
...
- set
...
- of
...
- data
...
- to
...
- be
...
- corrected,
...
- with
...
- an
...
- updated
...
- OAI-PMH
...
- record
...
- header
...
- datestamp.
...
- When
...
- the
...
- correction
...
- is
...
- a
...
- full
...
- deletion
...
- of
...
- the
...
- incorrect
...
- issued
...
- data,
...
- the
...
- OAI-PMH
...
- record
...
- has
...
- to
...
- be
...
- re-issued
...
- without
...
- a
...
- Context
...
- Object
...
- payload,
...
- with
...
- specified
...
- "<deleted>"
...
- flag
...
- and
...
- updated
...
- datestamp
...
- in
...
- the
...
- OAI-PMH
...
- record
...
- header.
...
- Records
...
- that
...
- fall
...
- out
...
- of
...
- the
...
- time
...
- frame
...
- for
...
- which
...
- the
...
- data
...
- provider
...
- offers
...
- data:
...
- These
...
- records
...
- are
...
- silently
...
- neglected,
...
- i.
...
- e.
...
- not
...
- offered
...
- via
...
- the
...
- OAI-PMH
...
- interface
...
- anymore,
...
- without
...
- using
...
- the
...
- deletion
...
- tracking
...
- features
...
- of
...
- OAI-PMH.
...
- Metadata
...
- formats
...
- OAI-PMH,
...
- 3.4All
...
- data
...
- providers
...
- have
...
- to
...
- provide
...
- support
...
- for
...
- <context-object>
...
- documents
...
- or
...
- <context-objects>
...
- aggregations,
...
- respectively.This
...
- choice
...
- also
...
- has
...
- to
...
- be
...
- announced
...
- in
...
- the
...
- response
...
- to
...
- the
...
- "listMetadataFormats"
...
- query
...
- OAI-PMH,
...
- 4.4
...
- by
...
- the
...
- data
...
- provider.
...
- While
...
- a
...
- specific
...
- "metadataPrefix"
...
- is
...
- not
...
- required,
...
- the
...
- information
...
- about
...
- "metadataNamespace"
...
- and
...
- "schema"
...
- is
...
- fixed
...
- for
...
- implementations:
...
Code Block xml xml linenumber true title metadataPrefix collapse true <metadataFormat> <metadataPrefix>ctxo</metadataPrefix> <schema>[http://www.openurl.info/registry/docs/xsd/info:ofi/] fmt:xml:xsd:ctx</schema><metadataNamespace>info:ofi/fmt:xml:xsd:ctx</metadataNamespace></metadataFormat>
| Info |
|---|
Using OAI-PMH, the mandatory MetadataPrefix for UpenURL Context Objects will be: "ctxo" |
...