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ddlGetIndexData(), ddlGetIndexDataNext(), ddlGetIndexDataPrevious()

Version 7.11

ddlGetIndexData(), ddlGetIndexDataNext(), ddlGetIndexDataPrevious()

 
   ddlGetIndexData(), ddlGetIndexDataNext(), ddlGetIndexDataPrevious()
 
Prototype:
   ddlGetIndexData(
      CONTROL *ctl,
      char *OptnString,
      char *ArgString,
      long BufferByteCount,      /* the size of buffer in bytes */
      char *Buffer);
 
   Structure used by ddlGetIndexData():
 
      typedef struct INDEXDATASTRUCT{
         short IndexItemStructSize;   /* [OUT] total number of bytes in this */
                                      /* structure element, including data */
         short IndexItemNullFlag;     /* [IN]/[OUT] 0 - item is not null */
                                      /*            1 - item is null */
         long IndexItemCount;         /* [OUT] this is the returned count */
         char IndexItemData[4];       /* [IN]/[OUT] place holder for data */
      }INDEXDATASTRUCT;
 
   Possible values for OptnString: NA
 
   Format of ArgString:
      <IndexName> [<RD-Name>] [[-]<Starting Position>]
      where
         <IndexName> is the name of the Thunderbolt Key
         <RD-Name> is an optional name of an RD that describes the
            format for delivering the index data to Buffer;
            if <Rd-Name> is not present, the index data is delivered
            in its native format;
            if <Rd-Name> is present, the index data is delivered
            in its native format, followed by the RD-specified format;
         <Starting Position> is an optional ascii numeric field;
            between 0 and 100.0 denoting the approximate starting position;
            Special values for <Starting Position> are:
               0 - [default] start at the beginning and read forward;
               100.0 - start at the end and read backward;
 
   Definition of BufferByteCount:
      This is the total number of bytes in Buffer. Items will
      be read until Buffer is full.
 
   Definition of Buffer:
      In this API function, Buffer is used only for output. The result 
      INDEXDATASTRUCT{} items are always returned in ascending order.
      Thus, if the index was read backward, the starting item is the
      last item in Buffer, rather than the first.
 
   Values returned in CONTROL structure:
      ctl.Ans1 - total number of items returned
 
   Description:
      The ddlGetIndexData() API function, and its ancillary functions
      ddlGetIndexDataNext() and ddlGetIndexDataPrevious() are special
      functions that will facilitate the retrieval of index data for 
      the purpose of Data Profiling.
 
      Note however, that in the general case, the data type
      and size of index data is not the same as the data type and size
      of the underlying field.
 
      Field type               Key type 
        Alpha                    Alpha
        Date                     Alpha
        Numeric (n <=9, d = 0)   Long Int
        Numeric (n <=6)          Float
        Numeric (n > 6)          Double
        Short Int                Long Int
        Long Int                 Long Int
        Long Int 64              Long Int 64
        Logical                  Long Int
        Float                    Float
        Double                   Double
 
      The ddlVerify() ... SIGNATURE function modifiers:
         SIGNATURE dgname fieldname KEYTYPE
         SIGNATURE dgname fieldname KEYLENGTH
      can be used to retrieve this information in a generic manner.
 
Prototype:
   ddlGetIndexDataNext(
      CONTROL *ctl,
      char *OptnString,
      char *ArgString,
      long BufferByteCount,      /* the size of buffer in bytes */
      char *Buffer);
 
   Possible values for OptnString: 
      /I  -   Include the node for the starting position, if it exists
      /L  -   Use Low Value for starting position; that is, ignore the
              incoming value in Buffer; and start at the first node;
              /I is implied with this option
   
   Format of ArgString:
      <IndexName>  [<RD-Name>]
      where
         <IndexName> is the name of the Thunderbolt Key
   
   Definition of BufferByteCount:
      This is the total number of bytes in Buffer. Items will
         be read until Buffer is full.
 
   Definition of Buffer:
      In this API function, the first item in Buffer is used
      as the starting position. Items are read following the
      starting position until Buffer is full or until there
      is no more data.

   Values returned in CONTROL structure:
      ctl.Ans1 - total number of items returned
 
Prototype:
   ddlGetIndexDataPrevious(
      CONTROL *ctl,
      char *OptnString,
      char *ArgString,
      long BufferByteCount,      /* the size of buffer in bytes */
      char *Buffer);
 
   Possible values for OptnString: 
      /H  -   Use High Value for starting position; that is, ignore the
              incoming value in Buffer; and start at the last node;
              /I is implied with this option
      /I  -   Include the node for the starting position, if it exists


   Format of ArgString:
      <IndexName>  [<RD-Name>]
      where
         <IndexName> is the name of the Thunderbolt Key

   Definition of BufferByteCount:
      This is the total number of bytes in Buffer. Items will
      be read until Buffer is full.

   Definition of Buffer:
      In this API function, the first item in Buffer is used
      as the starting position. Items are read preceeding the
      starting position until Buffer is full or until there
      is no more data.

     The result  INDEXDATASTRUCT{} items are always returned in ascending 
     order. Thus, if the index was read backward, the starting item is the
     last item in Buffer, rather than the first.
 
   Values returned in CONTROL structure:
      ctl.Ans1 - total number of items returned

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