Fujitsu UDS/SQL V2.5 用户手册
Universal Database System UDS/SQL
General information
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U929-J-Z125-9-76
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Central data protection measures
UDS/SQL incorporates effective, flexibly usable protective mechanisms to ensure that
each user group can access only precisely defined parts and sections of the database.
each user group can access only precisely defined parts and sections of the database.
UDS/SQL checks the user’s access rights before requests to the database are actually
executed.
executed.
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Simultaneous data access by many users
UDS/SQL permits application-independent data to be accessed by large numbers of
users simultaneously. Their requests are “time interleaved” for processing to optimize
overall throughput.
users simultaneously. Their requests are “time interleaved” for processing to optimize
overall throughput.
UDS/SQL also contains functions that prevent users from hindering each other when
they contend for access to the same record.
they contend for access to the same record.
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Central security concept
The security concept of UDS/SQL includes precautions to protect the data resources
against destruction or loss. Data resources which have been destroyed can be restored
to the most recent consistent status.
against destruction or loss. Data resources which have been destroyed can be restored
to the most recent consistent status.
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Support for mirrored disks
UDS/SQL supports DRV (Dual Recording by Volume). When DRV is used, the
operating system writes data to two disks simultaneously. This ensures increased avail-
ability and reliability since, even if one of the disks fails, all the data is still consistent,
up-to-date and available to the applications.
operating system writes data to two disks simultaneously. This ensures increased avail-
ability and reliability since, even if one of the disks fails, all the data is still consistent,
up-to-date and available to the applications.
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Support for the BS2000 access method FASTPAM
UDS/SQL supports the BS2000 access method FASTPAM, which provides a highly
efficient means of accessing files and realms of the database.
efficient means of accessing files and realms of the database.
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Support for uninterrupted time conversions
Support for uninterrupted time conversions ensures the continuous and uninterrupted
operation of UDS/SQL during seasonal conversions of the local time, e.g. when
converting from Central European Daylight Saving Time (MESZ) to Central European
Time (MEZ).
operation of UDS/SQL during seasonal conversions of the local time, e.g. when
converting from Central European Daylight Saving Time (MESZ) to Central European
Time (MEZ).