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Improve documentation of Unique class
* size represents the size of an element in the Unique class * full_size is used when the Unique class counts the number of duplicates stored per element. This requires additional space per Unique element.
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sql/sql_class.h

Lines changed: 9 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -3923,16 +3923,21 @@ class user_var_entry
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class Unique :public Sql_alloc
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{
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DYNAMIC_ARRAY file_ptrs;
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ulong max_elements;
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ulong max_elements; /* Total number of elements that will be stored in-memory */
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ulonglong max_in_memory_size;
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IO_CACHE file;
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TREE tree;
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uchar *record_pointers;
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/* Number of elements filtered out due to min_dupl_count when storing results
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to table. See Unique::get */
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ulong filtered_out_elems;
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bool flush();
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uint size;
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uint full_size;
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uint min_dupl_count; /* always 0 for unions, > 0 for intersections */
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uint size; /* Size of element stored in unique object. */
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uint full_size; /* Size of element + space needed to store the number of
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duplicates found for the element. */
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uint min_dupl_count; /* Minimum number of occurences of element required for
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it to be written to record_pointers.
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always 0 for unions, > 0 for intersections */
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bool merge(TABLE *table, uchar *buff, bool without_last_merge);
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