查询词典 bitmap

Bitmap indexes can include rows that have NULL values, unlike most other types of

与其他大多数索引不同，位图索引、可以包含键值为NULL的行。

Bitmap indexes include rows that have NULL values, unlike most other types of indexes. Indexing of nulls can be useful for some types of SQL statements, such as queries with the aggregate function COUNT.SELECT COUNT FROM employees

对于select count from tab，全表扫描比使用索引效率要高，经过分析的表cbo会倾向于使用索引，这是oracle软件的判断问题，最好还是不要收集统计信息，让oracle执行全表扫描。

Insert your Logo bitmap file in your project.

在项目中插入您的标志位图文件。

Graphic File Interchange, or Bitmap format files.

。图形档案交换，或位图

The application supports the following image formats: Windows bitmap, Windows Metafile, Icon, Graphic Interchange Format, JPEG File Interchange Format and Tag Image File Format.

应用支持以下图片格式： Windows位图， Windows元文件

The contributions are listed as follows:(1) a single-pass closed frequent itemsets mining process based on reverse lexicographic order FP-tree is introduced for mining classification association rules, which uses a kind of mixed item-ordering searching policy to satisfy the single-pass requirement of data streams and uses the bitmap technology to improve the efficiency;(2) the concept of self-support for filtering rules is proposed to improve the precision.

主要贡献在于：1提出了一种基于逆文法顺序FP-Tree的频繁闭项集单遍挖掘过程，用于挖掘类关联规则，该过程采用了一种混合项顺序搜索策略以满足数据流挖掘的单遍性需求，并采用位图技术提高效率：2提出了"自支持度"概念，用于筛选规则以提高算法分类精度。

A new sequential pattern algorithm based on depth-first search strategy is introduced and the mining mechanism based on lexicographic tree is presented in this paper.The data structure of bitmap is used in order to save and calculate the support of sequences fast.

提出了基于位图深度优先挖掘算法，采用基于字典树数据结构的深度优先策略，同时采用位图保存和计算各序列的支持度，能够较迅速地挖掘出频繁序列。

Bmp bitmap can implement binarization, median filtering, compensation omitted point, refinement to deal with.

详细说明：可以对bmp位图执行二值化，中值滤波，补偿遗漏点，细化处理。

Windows 98 continues to support the older bitmap-based fonts for compatibility and small memory requirements.

为了兼容性和少量内存要求，Windows 98 继续支持旧的基于位图的字体。

To metafile : converts the selected object to Windows Metafile Format, containing both bitmap and vector graphic data.

变成图元文件：转换选定的对象为Windows图元文件格式，同时包含点阵图和矢量图形数据。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。