mirror of https://gitee.com/bigwinds/arangodb
16 lines
637 B
Markdown
16 lines
637 B
Markdown
HashIndex {#GlossaryIndexHash}
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==============================
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@GE{Hash Index}: A hash index is used to find documents based on
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examples. A hash index can be created for one or multiple document
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attributes.
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A hash index will only be used by queries if all indexed attributes
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are present in the example or search query, and if all attributes are
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compared using the equality (`==` operator). That means the hash index
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does not support range queries.
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If the index is declared `unique`, then access to the indexed attributes
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should be fast. The performance degrades if the indexed attribute(s)
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contain(s) only very few distinct values.
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