| 摘要 |
PURPOSE:To shorten the data selecting time by selecting two data that have possibility for coincidence between the attribute contents designated as keys in terms for two data groups having the variable length data consisting of variable length attributes. CONSTITUTION:One of independent buffers 11-14 of a fixed capacity stores the length (l) of one or plural attributes designated as keys in a single tuple, a pair of values (v) and the address of the corresponding tuple. A key extracting device 17 extracts the contents of the attribute of the variable length designated as a key out of the tuple of the variable length. The variable length tuple is given from a data input terminal. A hashing device 18 contains a pair of a bit array 7 and a hashing circuit 5 which has a hashing action with an appropriate hash function. A key transmitting device 19 outputs the keys to a data output terminal 25 after selection.
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