Classifications

• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
  • G11B27/10—Indexing; Addressing; Timing or synchronising; Measuring tape travel
  • G11B27/102—Programmed access in sequence to addressed parts of tracks of operating record carriers
  • G11B27/105—Programmed access in sequence to addressed parts of tracks of operating record carriers of operating discs

Definitions

• Database systems access a stock of data.
• This stock of data is typically stored on a hard disk.
• the data are also stored in a ROM, as is the case with a voice database T9 for mobile radio telephones, for example.
• telephone books are stored on optical disks, such as CD-ROMs or DVD-ROMs, to some extent .
• the number of times that it is possible to rewrite to a sector is limited (between 1000 and 100 000 times, depending on media type) .
• the second index should be stored radially as close as possible to the first index. Ideally, it is written directly next to the first index. If write operations to the disk have taken place in the meantime, however, it may be that second or updated data have already been set down after the first index. In this case, the second index should then be written to the next free storage location of sufficient size, which means that a skip from the first index to the second index is as small as possible. This is because shorter skips on the optical disk can be performed much more quickly than longer ones.
• the small spacing between the two indices, or the fact that they are written directly next to one another thus allows the access speed to the index to be increased, because normally both indices need to be sought during a search operation.
• the second index may also be stored before the first index, provided that storage space is available. This has advantages particularly when certain search strategies require only the second index to be searched for the changes or updates.
• the identification number undershoots the prescribable threshold value. This is the case particularly if one of the two indices were very small and hence combination allows a skip by the read head to be avoided.
• step S4 When ascertaining the identification number (step S4), it is possible to include the following criteria, for example.
• step S5 If the identification number exceeds the threshold value, which is checked in step S5, the following procedures are recommended:
• step S7 If no method has been found for undershooting the threshold value, regenerate the index list (step S ⁇ ) and free memory for the old index list (first index) together with memory for all changes (second and third index) . Next, store the new index list as cohesively as possible (step S7).
• the threshold value may be a fixed variable or is ascertained in a similar manner to the identification number on the basis of the state of the plate.
• the identification number may assess the time for reading in the index or indices, and the threshold value may instead be calculated from the number of times that the medium has already been overwritten, the memory which is still available on the disk and the degree of fragmentation of the disk.
• there may be a comparison of how high the gain (time saving for the read-in/rewrite stress for the medium) would be if the index list were to be stored again, as compared with the situation in which only a change would be stored.

Landscapes

• Signal Processing For Digital Recording And Reproducing (AREA)
• Information Retrieval, Db Structures And Fs Structures Therefor (AREA)
• Automatic Disk Changers (AREA)
• Management Or Editing Of Information On Record Carriers (AREA)

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• 2004
  • 2004-01-06 DE DE102004001207A patent/DE102004001207A1/de not_active Withdrawn
  • 2004-10-25 EP EP04300718A patent/EP1553597A2/en not_active Withdrawn
  • 2004-11-22 WO PCT/EP2004/013241 patent/WO2005069300A1/en not_active Ceased
  • 2004-11-22 US US10/584,744 patent/US7543107B2/en not_active Expired - Fee Related
  • 2004-11-22 EP EP04798040A patent/EP1702330A1/en not_active Withdrawn
  • 2004-11-22 JP JP2006545946A patent/JP4701186B2/ja not_active Expired - Fee Related
  • 2004-11-22 CN CN2004800398460A patent/CN1902704B/zh not_active Expired - Fee Related
  • 2004-12-30 TW TW093141330A patent/TWI370443B/zh not_active IP Right Cessation
• 2005
  • 2005-01-04 MY MYPI20050015A patent/MY140138A/en unknown

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