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导入导出时直接路径比普通路径快

原创 Linux操作系统 作者:杨奇龙 时间:2010-07-19 22:50:28 0 删除 编辑
     Conventional path Export uses the SQL SELECT statement to extract data from tables. Data is read from disk into a buffer cache, and rows are transferred to the evaluating buffer. The data, after passing expression evaluation, is transferred to the Export client, which then writes the data into the export file.

    Direct path Export is much faster than conventional path Export because data is read from disk into the buffer cache and rows are transferred directly to the Export client. The evaluating buffer is bypassed. The data is already in the format that Export expects, thus avoiding unnecessary data conversion. The data is transferred to the Export client, which then writes the data into the export file

来自 “ ITPUB博客 ” ,链接:https://blog.itpub.net/22664653/viewspace-668416/ ,如需转载,请注明出处,否则将追究法律责任。

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