它们仅针对字符串列进行收集，查询优化器用它们来提高“column LIKE ' % abc '”和“column LIKE ' % abc % '”类型谓词的选择性估计。

They are collected for string columns only, and they are used by the query optimizer to improve the selectivity estimates for predicates of the type "column LIKE '% ABC'" and "column LIKE '% ABC %'".

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方法：收集6例疑诊右侧肾上腺嗜铬细胞瘤病人行腹主动脉及选择性肾上腺动脉造影检查及数字电影摄影。

Methods: the abdominal aortography, the selective angiography of suprarenal artery and digital cine photograph were performed in 6 patients with doubtful right adrenal pheochromocytomas.

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