GB2283593A - Data storage and retrieval apparatus. - Google Patents
Data storage and retrieval apparatus. Download PDFInfo
- Publication number
- GB2283593A GB2283593A GB9322944A GB9322944A GB2283593A GB 2283593 A GB2283593 A GB 2283593A GB 9322944 A GB9322944 A GB 9322944A GB 9322944 A GB9322944 A GB 9322944A GB 2283593 A GB2283593 A GB 2283593A
- Authority
- GB
- United Kingdom
- Prior art keywords
- data
- memory circuit
- server device
- file
- service
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F16/00—Information retrieval; Database structures therefor; File system structures therefor
- G06F16/10—File systems; File servers
Abstract
An apparatus (1) comprises a server device (2) which stores a data file in a memory circuit (31 - Fig. 2) and provides a very fast response to queries transmitted on a network (6). The memory circuit is locked and effective hard-wire links are established between memory blocks in an index circuit (30 - Fig. 2) and the memory circuit (31). The memory circuit is initialised from disk drives on an administration processor (4) and a service processor (35 - Fig. 2) is initialised by reference to a service definition file transmitted from a memory circuit (34 - Fig. 2) to a memory circuit (28 - Fig. 2) in the server device (2). The administration processor (4) allows up-dating of data on databases in an off-line manner from the server device (2), the latter device being capable of providing very fast response time by routing of requests through the memory circuits (30, 31). <IMAGE>
Description
"A Data Storage and Retrieval Apparatus"
This invention relates to interactivity of an apparatus when interfacing with a user.
Much work has been carried out heretofore in the development of data processing apparatus, including data processing networks. For example, sophisticated network systems are described in European Patent Specification
Numbers EP-A2-0163577 (DEC) and EP-B1-0374134 (DEC).
United States Patent Specification No. 4 104 717 describes an automatic telephone information retrieval system. This system undoubtedly provides for a fast response in the retrieval of data. However, the system is relatively complex and involves use of an audiotape reproducer, an automatic answering device, a tape recorder, and various other items. The invention is directed towards providing an apparatus which is relatively inexpensive to produce and which provides for storage and retrieval of data in a manner which provides for a very fast response time to the user. Indeed, an object of the invention is that the response time be almost instantaneous as observed by the user. Another object is that the apparatus be easily integrated into an existing data processing network apparatus so that there is a minimum of additional hardware and software required by the user for installation.
According to the invention there is provided a data storage and retrieval apparatus comprising a network interconnecting a data access terminal, a server device, and an administration processor wherein:the administration processor comprises :
means for controlling storage of databases on a storage
device connected thereto; and
means for controlling transmission to the server device
of each database stored on the storage device connected
to the administration processor, the database being
transmitted as a delimited flat format data file.
for operating in an initialisation mode, the server device comprising
means for receiving the data file and writing it to a
memory circuit;
means for locking the memory circuit;
means for accessing the data file and determining and
identifying each of the index fields of the data file,
and for each index field generating an index memory
block of addresses in the locked memory circuit;
means for carrying out repeated fetch cycles to the
data file to sort the addresses in each index memory
block in ascending key to establish an effective hard
wire link between the index memory block and the
associated fields of the data file in the locked memory
circuit; and
means for broadcasting a signal on the network to
indicate that the server device is initialised for data
access requests, the data access terminal comprises means for transmitting a data request signal to the server device, the request signal indicating at least portion of a field value for the data file; and for operating in server mode, the server device comprising:
means for reading the data request signal and carrying
out a search through the relevant memory block and
reading data file field values until the requested
record is identified;
means for transmitting the identified record on the
network to the data access terminal;and
means for at the end of a data access session
broadcasting a signal on the network that the server
mode is discontinued and un-locking the memory circuit.
Preferably, the server device stores a service definition file during server mode, the service definition file including data relating to transmission of responses to queries including screen layouts.
In one embodiment, the service definition file is stored on the administration processor and is transmitted to the server device during the initialisation mode, the administration processor comprising a means for up-dating the service file.
In one embodiment, the server device includes a memory circuit storing server context data tor each user on the network, and the server device further comprises means for referring to said memory circuit before transmitting a response to a query to ensure security conditions are adhered to.
Ideally, the server device comprises a means for carrying out a binary search on the memory block indexes for fast retrieval of data.
The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only with reference to the accompanying drawings in which :
Fig. 1 is a schematic diagram showing in broad outline
a data storage and retrieval apparatus of the
invention;
Fig. 2 is a detailed diagram showing the apparatus;and
Fig. 3 is a diagram showing the manner in which data is
retrieved in the apparatus.
Referring initially to Fig. 1, a data processing apparatus 1 of the invention is shown. The apparatus 1 comprises a server device 2 which stores data files 3 and which operates in conjunction with an administration processor 4. The apparatus 1 includes a client or data access terminal 5 which is connected to the server 2 via a local area network 6. In very brief outline, the apparatus 1 operates by the server device 2 retrieving information including a service definition file 7 from the administration processor 4 during initialisation. In its active mode, the server device 2 receives data access queries from the data access terminal 5 and retrieves data and writes it to the terminal 5 via the network 6 as indicated by the arrows of Fig. 1. There may be many data access terminals 5 on the network 6, however, only one is illustrated, for clarity.
Referring now to Fig. 2, the apparatus 1 is shown in more detail. The data access terminal 5 is connected to the network 6 by a driver 20. A driver 21 having control blocks and buffer circuits connects the network 6 to the server device 2.
The server device 2 comprises a main processor 25 which is connected to API circuits of the driver 21. The main processor 25 is connected to a user service context pointer array 26 which operates in conjunction with the main processor 25 for retrieval of service data for each user on the network 6 stored in a memory circuit 27. Such data includes password data and general access control data which is particular to each individual user.
The server device 2 also includes a service control memory circuit 28 which interacts with an equivalent service control memory circuit 34 in the administration processor 4. The server device 2 also includes a set of buffers 29 connected to various memory circuits, and the service control memory circuit 28 is also connected to an index memory circuit 30 which operates in conjunction with a data file memory circuit 31.
Finally, the administration processor 4 comprises the above-mentioned service control memory circuit 34 which is controlled by a main processor 36, the latter of which is also connected to a set of disk drives 35 which store databases. Each database is associated with a single data file 3 as illustrated in Fig. 1.
The various items of the apparatus 1 are constructed to carry out the necessary functions to provide an extremely fast response time to a data request query transmitted from a data access terminal. These terminals are best explained by way of explaining operation of the apparatus 1.
The apparatus 1 is initialised by activation of the administration processor 4 which on an on-going basis controls storage of databases on the disk drives 35. In this embodiment there are three databases. The processor 36 in conjunction with the server control memory circuit 34 directs transmission of each database in turn as a data file in delimited ASCII format to the large memory circuits 31 of the server device 2. In this embodiment, the memory circuit 31 has a capacity of 30 megabytes so that it can comfortably accommodate three data files. The structure of each data file may, for example, be TAB delimiting for fields and RETURN delimiting for records.
An important point is that they are in ASCII format. Once the server processor 25 detects successful writing of the data file to the memory circuit 31, it immediately locks the circuit 31 by preventing write enable instructions being transmitted to it.
The service control memory circuit 34 of the administration processor 4 stores a service definition file associated with databases. Each service definition file includes :
- screen layout control signals;
- index field numbers for fields in the database
indicating their location for display on screens
for the data access terminals 5;
- address information including an operating system
path to the data file on the memory circuit 31 of
the server device 2.
Upon activation, the administration processor 36 directs transmission of the service definition file from the memory circuit 34 to the memory circuit 28 of the service device 2. The server processor 25 then reads the server definition file on the circuit 28 and accesses the data file on the memory circuit 31. It initially identifies each of the index fields and for each such field it generates an index memory block in the memory circuit 30.
As shown in Fig. 3, each memory block is in the form of a column being four bytes wide, this being the necessary memory location size required for storage of an address for the memory circuit 31. The processor 25 carries out repeated fresh cycles to the memory circuit 31 so that it sorts the memory block addresses according to sort order for the field values. For example, an index field number one may include surnames and the sort is then according to alphabetical order. Sorting is carried out with reference to subsidiary index field values and in this example index field 2 would relate to Christian Names and sorting of the first memory block is carried out with reference to the second memory block so that fields with the same surname are sorted according to Christian Names. The end result of these operations is in effect a hard-coded link between the memory circuits 30 and 31. The memory circuit 31 has in this example three memory blocks 40,41 and 42 associated with index field 1,2 and 3 respectively. The memory circuit 31 stores the data file which comprises in this example a set of delimited records, each record having three fields, F1, F2 and F3. The memory block 40 of the circuit 30 is associated with all of the fields F1, the memory block 41 being associated with all the fields
F2, and the memory block 42 being associated with all of the fields F3. The hard-coded or wired links 45 are shown for some examples. These links may be regarded as being hard-coded or hard-wired because the data file in the memory circuit 31 is locked and the entries in the memory blocks 40,41 and 42 are addresses leading directly to the relevant fields in the memory circuit 31. This sort of operation is repeated for each of the three databases so that there are three data files and associated sets of memory blocks on the circuits 31 and 30.
When initialisation has been complete, the server device 2 transmits a signal on the network 6 indicating that it is available for service. This sets a status flag on each of the terminals 5.
When data is required by a user, he or she inputs a portion of the required data such as a surname into his or her terminal 5 and this is transmitted to the server device 2. The processor 25 initially refers to the service context memory circuit 27 to determine data access information about the user. The processor 25 then carries out a binary search in the memory block associated with the field for which data has been inputted in the query.
The binary search involves initially checking the field value associated with the centre address in the relevant memory block and depending on whether or not this is high or low, retrieving the value associated with the centre entry in the top or bottom half of the memory block, and so on. This has been found to be an extremely effective and quick way of retrieving data. Depending on the amount of information transmitted in the data request query, record values are retrieved from the memory circuit 31 and are transmitted via the driver 21 on the network 6 to the data access terminal 5. The amount of data which is transmitted depends on the security level retrieved from the circuit 27 initially.
It has been found that because of the effect of hard-wired links between the memory circuits 30 and 31 and because of the manner in which the apparatus 1 operates in general by use of the service definition file and the circuit 27, an extremely fast response time is provided to the user.
Indeed, it has been found that as few as twelve fetch cycles are required for one comparison. This provides an instantaneous response as far as the user is concerned as he or she does not notice the extremely small time lag in retrieval of the information. Data access queries are handled in this way for all of the duration of operation of the apparatus 1.
At the end of a particular data access time, the server device 2 transmits a signal indicating this fact to the administration processor 36 and transmits a write enable signal for memory accesses to the memory circuit 31. This allows writing over the data which is stored and the hardwire links between the circuits 30 and 31 are effectively broken. While the server device 2 had been in operation in providing the data access service, the administration processor 4 may have received instructions for up-dating of the database on the disk 35. Therefore, at the next initialisation stage, different data files will be transmitted to the memory circuit 31 and the operation is then repeated with the updated database.
It has been found that operation of the server device 2 in conjunction with the administration processor 4 is extremely effective at providing for very fast data access replies. Data integrity is also improved by virtue of the fact that all data updates are routed through the administration processor 4 without interrupting operation of the service device 2. The updated database is then used as the basis for transmission of a data file at the next service session.
The invention is not limited to the embodiments hereinbefore described but may be varied in construction and detail.
Claims (5)
1. A data storage and retrieval apparatus comprising a
network interconnecting a data access terminal, a
server device, and an administration processor wherein: - the administration processor comprises :
means for controlling storage of databases on a
storage device connected thereto; and
means for controlling transmission to the server
device of each database stored on the storage
device connected to the administration processor,
the database being transmitted as a delimited flat
format data file.
for operating in an initialisation mode, the server
device comprising :
means for receiving the data file and writing it
to a memory circuit;
means for locking the memory circuit;
means for accessing the data file and determining
and identifying each of the index fields of the
data file, and for each index field generating an
index memory block of addresses in the locked
memory circuit;
means for carrying out repeated fetch cycles to
the data file to sort the addresses in each index
memory block in ascending key to establish an
effective hard-wire link between the index memory
block and the associated fields of the data file
in the locked memory circuit;and
means for broadcasting a signal on the network to
indicate that the server device is initialised for
data access requests,
the data access terminal comprises means for
transmitting a data request signal to the server
device, the request signal indicating at least portion
of a field value for the data file; and
for operating in server mode, the server device
comprising :
means for reading the data request signal and
carrying out a search through the relevant memory
block and reading data file field values until the
requested record is identified;
means for transmitting the identified record on
the network to the data access terminal;and
means for at the end of a data access session
broadcasting a signal on the network that the
server mode is discontinued and un-locking the
memory circuit.
2. An apparatus as claimed in Claim 1, wherein the server
device stores a service definition file during server
mode, the service definition file including data
relating to transmission of responses to queries
including screen layouts.
3. An apparatus as claimed in Claim 2, wherein the service
definition file is stored on the administration
processor and is transmitted to the server device
during the initialisation mode, the administration
processor comprising a means for up-dating the service
file.
4. An apparatus as claimed in any preceding claim, wherein
the server device includes a memory circuit storing
server context data for each user on the network, and
the server device further comprises means for referring
to said memory circuit before transmitting a response
to a query to ensure security conditions are adhered
to.
5. An apparatus substantially as hereinbefore described
with reference to and as illustrated in the
accompanying drawings.
5. An apparatus as claimed in any preceding claim, wherein
the server device comprises a means for carrying out a
binary search on the memory block indexes for fast
retrieval of data.
6. An apparatus substantially as hereinbefore described,
with reference to and as illustrated in the
accompanying drawings.
Amendments to the claims have been filed as follows 1. A data storage and retrieval apparatus to provide a
fast data access service during a service session, the
apparatus comprising a network to which is connected a
plurality of user terminals, an administration device
and a separate server device, wherein :
the administration device comprises :
an administration processor;
a set of storage devices for storing databases;
and
a service control memory circuit,
the administration processor comprises means for
operating in an initialisation mode before a service
session by carrying out the steps of :
automatically retrieving each database in turn
from the storage devices and writing each database
to the service control memory circuit as a data
file in a common, de-limited format; and
transmitting a service definition file to the
service control memory circuit, said file having
data access parameter values for the data files
and data display parameter values,
the administration processor further comprises means
for operating during a service session to process
regular data updates directly to the databases in the
storage devices, the server device comprises
a service processor;
a service control memory circuit;
a data file memory circuit having a capacity in
excess of 25 MB; and
an index memory circuit, the server processor comprises means for operating in the initialisation mode to carry out the steps of :
retrieving the service definition file and
each data file from the administration device
service control memory circuit, writing the
service definition file to the server device
service definition control circuit, and
writing each data file directly to the data
file memory circuit;
automatically locking the data file memory
circuit to prevent write operations after
verification of a successful write operation
of the data files; and
reading both the data file and the service
definition file to determine indexes for
access to the data in the data file memory
circuit, said indexes comprising memory
blocks, each memory block being directly
associated with a set of data fields within
the data file memory circuit to establish
hard-coded links;
the server processor comprises means for receiving data
access requests from a network driver during a service
session and accessing requested data via the index
memory circuit using the hard-coded links, and
directing transmission of the data to the network, and
the server processor comprises means for automatically
transmitting a write enable signal to the data file
memory circuit at the end of the service session.
2. An apparatus as claimed in claim 1, wherein the server
device further comprises a context memory circuit and
the server processor comprises means for directing
storage in said memory circuit of server context data
for each user on the network and further comprises
means for referring to said memory circ ,t before
transmitting a response to a data access request to
ensure security conditions are adhered to.
3. An apparatus as claimed in claims 1 or 2, wherein the
server processor comprises means for carrying out a
binary search on the memory block indexes for fast
retrieval of data.
4. An apparatus as claimed in any preceding claim wherein
the data file memory circuit has a capacity of
approximately 30 MB.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9322944A GB2283593A (en) | 1993-11-08 | 1993-11-08 | Data storage and retrieval apparatus. |
| BE9301256A BE1005873A6 (en) | 1993-11-08 | 1993-11-12 | APPARATUS FOR STORING AND CONSULTING DATA. |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9322944A GB2283593A (en) | 1993-11-08 | 1993-11-08 | Data storage and retrieval apparatus. |
| BE9301256A BE1005873A6 (en) | 1993-11-08 | 1993-11-12 | APPARATUS FOR STORING AND CONSULTING DATA. |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB9322944D0 GB9322944D0 (en) | 1994-01-05 |
| GB2283593A true GB2283593A (en) | 1995-05-10 |
Family
ID=25662812
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB9322944A Withdrawn GB2283593A (en) | 1993-11-08 | 1993-11-08 | Data storage and retrieval apparatus. |
Country Status (2)
| Country | Link |
|---|---|
| BE (1) | BE1005873A6 (en) |
| GB (1) | GB2283593A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SG87751A1 (en) * | 1995-12-18 | 2002-04-16 | Sony Corp | Telephone system using internet |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0163577A2 (en) * | 1984-06-01 | 1985-12-04 | Digital Equipment Corporation | Local area network for digital data processing system |
-
1993
- 1993-11-08 GB GB9322944A patent/GB2283593A/en not_active Withdrawn
- 1993-11-12 BE BE9301256A patent/BE1005873A6/en not_active IP Right Cessation
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0163577A2 (en) * | 1984-06-01 | 1985-12-04 | Digital Equipment Corporation | Local area network for digital data processing system |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SG87751A1 (en) * | 1995-12-18 | 2002-04-16 | Sony Corp | Telephone system using internet |
Also Published As
| Publication number | Publication date |
|---|---|
| BE1005873A6 (en) | 1994-02-22 |
| GB9322944D0 (en) | 1994-01-05 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |