Database system

Claim 2

A database system provided in a network system capable of exchanging data, and capable of storing and retrieving the data via the network system, comprising: first data file means, having a rewritable memory unit, for storing data supplied through the network system; second data file means, having a memory unit with a larger memory capacity than that of said memory unit of the first data file means, for storing data to be transferred from said first data file means; and file management means, for managing the access and storage of data in both said first and second data file means, said file management means being responsive to a utilization characteristic of data stored in said first data file means.

Claim 3

A system according to claim 1, wherein: said first data file means comprises a plurality of file means that are distributed via the network system.

Claim 4

A system according to claim 1, wherein said second data file means comprises a plurality of file means that are distributed via the network system.

Claim 5

A system according to claim 1, wherein: said second data file means includes file means connected to said first data file means but not through the network system.

Claim 6

A system according to claim 2, wherein: said plurality of file means are means for storing different types of data that are classified in advance.

Claim 7

A system according to claim 21, wherein: said file management means comprises a plurality of index data memory means distributed on the network system.

Claim 8

A system according to claim 6, wherein: said plurality of index data memory means includes rewritable memory means.

Claim 9

A system according to claim 1, wherein: said file management means includes means for directly transferring data read out from said second data file means to said network system.

Claim 10

A system according to claim 1, wherein: said first data file means includes data companding means for compressing and then storing data, and for expanding and outputting readout data, and alternatively said second data file means includes data companding means for compressing and then storing data, and for expanding and outputting readout data.

Claim 11

A system according to claim 1, wherein: said second data file means includes data editing means for editing data stored in said memory unit before it is stored.

Claim 12

A system according to claim 1, wherein: said first data file means includes buffer memory means for temporarily storing data supplied via the network system.

Claim 13

A system according to claim 1, wherein: said file management means includes counter means for counting an elapsed time since data stored in said first data file means is accessed in units of predetermined data groups, and control means for transferring a data group to said second data file means when the elapsed time obtained by said counter means reaches a predetermined value.

Claim 14

A system according to claim 1, wherein: said file management means includes counter means for counting an elapsed time since data stored in said second data file means is accessed in units of predetermined data groups, and control means for deleting a data group from said second data file means when the elapsed time obtained by said counting means reaches a predetermined value.

Claim 15

A system according to claim 1, wherein: said file management means includes control means which, when data stored in said second data file means is accessed, transfers a predetermined data group including the accessed data from said second data file means to first data file means.

Claim 16

A system according to claim 1, wherein: said system further comprises a third data file means, which has a rewritable memory unit having a memory capacity larger than that of said memory unit of the first data file means and smaller than that of said memory unit of the second data file means, for storing data transferred from said first data file means, and said second data file means is a means for storing data transferred from said memory unit of the third data file means.

Claim 17

A system according to claim 1, further comprising: a fourth data file means, which has a non-rewritable memory unit with a memory capacity larger than that of said memory unit of the second data file means, for storing data transferred from said second data file means.

Claim 18

A system according to claim 16, wherein: said memory unit of the second data file means is an optical disc unit having an optical disc as a data recording medium, and said fourth data file means includes a memory unit comprising an optical disc stock unit capable of stocking a plurality of optical discs and carrying means for moving an optical disc between said optical disc stock unit and said optical disc unit.

Claim 19

A system according to claim 1, wherein: said first data file means includes first data companding means for compressing and then storing data, and for expanding data to be read out and then outputting decoded data, and said second data file means includes second data companding means for compressing data with a higher compressing ratio than that of said first companding means and then storing the compressed data, and for expanding data to be read out, and outputting its decoded data.

Claim 20

A system according to claim 18, wherein: said first data companding means is a data companding means capable of completely decoding compressed data, and said second data companding means is a data companding means wherein data decoded thereby is degraded in accordance with a compression ratio thereof.

Claim 21

A database system provided in a network system capable of exchanging data, and capable of storing and retrieving the data via the network system, comprising: first data file means, having a rewritable memory unit, for storing data supplied through the network system; second data file means, having a memory unit with a larger memory capacity than that of said memory unit of the first data file means, for storing data to be transferred from said first data file means; and file management means, for managing the access and storage of data in both said first and second data file means, said file management means being responsive to a utilization characteristic of data stored in said first data file means; a third data file means, which has a rewritable memory unit having a memory capacity larger than that of said memory unit of the first data file means and smaller than that of said memory unit of the second data file means, for storing data transferred from said first file means, and said second data file means is a means for storing data transferred from said memory unit of the third data file means; a fourth data file means, which has a non-rewritable memory unit with a memory capacity larger than that of said memory unit of the second data file means, for storing data transferred from said second data file means; said memory unit of the second data file means is an optical disc unit having an optical disc as a data recording medium, and said fourth data file means includes a memory unit comprising an optical disc stock unit capable of stocking a plurality of optical discs and carrying means for moving an optical disc between said optical disc stock unit and said optical disc unit.

Claim 22

A database system provided in a network system capable of exchanging data, and capable of storing and retrieving the data via the network system, comprising: first data file means, having a rewritable memory unit, for storing data supplied through the network system; second data file means, having a memory unit with a larger memory capacity than that of said memory unit of the first data file means, for storing data to be transferred from said first data file means; and file management means, for managing the access and storage of data in both said first and second data file means, said file management means being responsive to a utilization characteristic of data stored in said first data file means; a third data file means, which has a rewritable memory unit having a memory capacity larger than that of said memory unit of the first data file means and smaller than that of said memory unit of the second data file means, for storing data transferred from said first file means, and said second data file means is a means for storing data transferred from said memory unit of the third data file means; a fourth data file means, which has a non-rewritable memory unit with a memory capacity larger than that of said memory unit of the second data file means, for storing data transferred from said second data file means; said memory unit of the second data file means is an optical disc unit having an optical disc as a data recording medium, and said fourth data file means includes a memory unit comprising an optical disc stock unit capable of stocking a plurality of optical discs and carrying means for moving an optical disc between said optical disc stock unit and said optical disc unit.

Claim 23

A database system provided in a network system capable of exchanging data, and capable of storing and retrieving the data via the network system, comprising: first data file means, having a rewritable memory unit, for storing data supplied through the network system; second data file means, having a memory unit with a larger memory capacity than that of said memory unit of the first data file means, for storing data to be transferred from said first data file means; and file management means, for managing the access and storage of data in both said first and second data file means, said file management means being responsive to a utilization characteristic of data stored in said first data file means; said first data file means includes first data companding means for compressing and then storing data, and for expanding data to be read out and then outputting the decoded data, and said second data file means includes second data companding means for compressing data with a higher compressing ratio than that of said first companding means and then storing the compressed data, and for expanding data to be read out, and outputting the decoded data; said first data companding means is a data companding means capable of completely decoding compressed data, and said second data companding means is a data companding means wherein data decoded thereby is degraded in accordance with a compression ratio thereof.

Claim 24

A database system provided in a network system capable of exchanging data, and capable of storing and retrieving the data via the network system, comprising: first data file means, having a rewritable memory unit, for storing data supplied through the network system; second data file means, having a memory unit with a larger memory capacity than that of said memory unit of the first data file means, for storing data to be transferred from said first data file means; and file management means, for managing the access and storage of data in both said first and second data file means, said file management means being responsive to a utilization characteristic of data stored in said first data file means; said first data file means includes first data companding means for compressing and then storing data, and for expanding data to be read out and then outputting the decoded data, and said second data file means includes second data companding means for compressing data with a higher compressing ratio than that of said first companding means and then storing the compressed data, and for expanding data to be read out, and outputting the decoded data; said first data companding means is a data companding means capable of completely decoding compressed data, and said second data companding means is a data companding means wherein data decoded thereby is degraded in accordance with a compression ratio thereof.