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wl-1884 storing NULL in ordered index

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2004-07-27 13:20:37 +02:00
parent 0c6d41a86e
commit 2f4d0e1e1d
9 changed files with 150 additions and 117 deletions
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27
ndb/include/ndbapi/NdbIndexScanOperation.hpp
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@ -86,26 +86,25 @@ public:
/**
* Define bound on index key in range scan.
*
* Each index key can have not null lower and/or upper bound, or can
* be set equal to not null value. The bounds can be defined in any
* order but a duplicate definition is an error.
* Each index key can have lower and/or upper bound, or can be set
* equal to a value. The bounds can be defined in any order but
* a duplicate definition is an error.
*
* The scan is most effective when bounds are given for an initial
* sequence of non-nullable index keys, and all but the last one is an
* equality. In this case the scan returns a contiguous range from
* each ordered index fragment.
* The bounds must specify a single range i.e. they are on an initial
* sequence of index keys and the condition is equality for all but
* (at most) the last key which has a lower and/or upper bound.
*
* @note This release implements only the case described above,
* except for the non-nullable limitation. Other sets of
* bounds return error or empty result set.
* NULL is treated like a normal value which is less than any not-NULL
* value and equal to another NULL value. To search for NULL use
* setBound with null pointer (0).
*
* @note In this release a null key value satisfies any lower
* bound and no upper bound. This may change.
* An index stores also all-NULL keys (this may become optional).
* Doing index scan with empty bound set returns all table tuples.
*
* @param attrName Attribute name, alternatively:
* @param anAttrId Index column id (starting from 0).
* @param anAttrId Index column id (starting from 0)
* @param type Type of bound
* @param value Pointer to bound value
* @param value Pointer to bound value, 0 for NULL
* @param len Value length in bytes.
* Fixed per datatype and can be omitted
* @return 0 if successful otherwise -1