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Adabas 201 For The Natural Programmer

Efficient Adabas Access ADABAS Access * Select the correct access method. * Code it efficiently. ã ã ã ã ã 2 READ PHYSICAL READ BY ISN (GET) READ LOGICAL FIND HISTOGRAM Natural Commands READ Physical Data Storage ã Use when reading more than 20% of the records in a file ã Generally least expensive method to read all records ã Only update if ã Potential double updates will not be a problem ã Restorability not a problem ã Safest to run when file not being updated 3 ADABAS Access READ PHYSI

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  Efficient Adabas Access  2  ADABAS Access ã READ PHYSICALã READ BY ISN (GET)ã READ LOGICALã FINDã HISTOGRAM * Select the correct access method.* Code it efficiently.  3 Natural Commands READ PhysicalData StorageãUse when reading more than 20% of the records in a fileãGenerally least expensive method to read all recordsãOnly update if ãPotential double updates will not be a problemãRestorability not a problemãSafest to run when file not being updated   4  ADABAS Access - READ PHYSICAL ã  Access to Data Storage only.ã Records returned in the order they are stored physically in Data Storage * Can results in 4 I/Os (1 per block) & 14 ADABAS Calls* Can results in 4 I/Os (1 per block) & 14 ADABAS Calls* Order of records returned: 2,1,14,3,5,12,4,6,7,8,11,9,20,21* Order of records returned: 2,1,14,3,5,12,4,6,7,8,11,9,20,21