The system catalog does not identify which columns contain encrypted data, and the same column can include both encrypted and unencrypted values.
系统目录没有标识哪些列中包含加密的数据，同一列中可以同时包含加密和非加密数据。
Without column data-value distribution information in the catalog, DB2 will assume an even distribution of values, which may lead the optimizer to a sub-optimal access path.
如果编目中没有列数据值分布信息，DB 2就会假设值是均匀分布的，这可能导致优化器选择非最优的访问路径。
Create a database table, Catalog, for example, with an XML type column.
用xml类型列创建一个数据库表，比如catalog。
The following example illustrates using RUNSTATS to collect catalog statistics that capture column group information
下列例子说明了如何使用RUNSTATS收集捕获了列组信息的目录统计信息
Example 19: Collect catalog statistics that capture column groups.
示例19：收集捕获了列组的目录统计信息。
Example 20: Collect catalog statistics on all columns and LIKE statistics on a specific VARCHAR column.
示例20：收集所有列上的目录统计信息并指定varchar列上的LIKE统计信息。
A new version column is added to sysfragments system catalog table to keep track of changes to statistics information.
在sysfragments系统目录表格中添加一个新版本的列，跟踪统计信息更改。
Example 17: Collect catalog statistics on all indexes and on column deptname with distribution.
示例17：收集所有索引上的目录统计信息，包含列deptname 上的分布统计信息。
Example 12: Collect catalog statistics on only the table, with basic column statistics for deptno and deptname and distribution statistics on mgrno and admrdept.
示例12：只收集表上的目录统计信息，包含deptno和deptname上的基本列统计信息以及mgrno和admrdept上的分布统计信息。
By querying the STATUS column of the SYSCAT.DATAPARTITIONS catalog view for the partition in question.
通过针对问题分区来查询SYSCAT .DATAPARTITIONS目录视图的列s TATUS。
A copy of the DBRM is stored in the DB2 catalog (our DB2 "SOURCELIB") for documentation and future REBINDs (a topic left for another column).
DBRM的副本存储在DB 2目录中(DB 2“SOURCELIB”)，以便进行记录和用于未来的REBIND(留作另一专栏的主题)。
Data distributions are generated by the server for individual columns of a table, and are stored as encoded histograms in the encdat column of the sysdistrib system catalog.
服务器为表中的各个列生成数据分布，这些数据分布被以编码直方图的形式存储在sysdistrib系统编目的encdat列中。
Using the catalog table from the STORES_DEMO database as an example, we might be interested in searching the catalog descriptions (cat_descr column).
使用STORES_DEMO数据库中的catalog表作为例子，我们可能对搜索目录描述(cat _ descr栏)感兴趣。
Example 2: Collect catalog statistics on individual column names.
示例2：收集单个列上的目录统计信息。
The figure below shows a registered spatial column (location in table wells_pts) in the spatial Extender catalog.
下面的图显示Spatial Extender编目中注册的一个空间列(wells_pts中的location)。
This is because table and column names are typically folded into uppercase before being written to DB2's internal catalog.
这是因为表名和列名在被写入到DB2的内部编目之前通常要换成大写形式。
A catalog view can be based on one or more catalog tables, and the view column names are often different than their counterparts in the catalog table.
一个编目视图可以基于一个或多个编目表，并且视图中的列名常常与它们在编目表中对应的列不同。
Example 4: Collect catalog statistics on key columns and on one column that is not.
示例4：收集关键列上和一个非关键列上的目录统计信息。
The information about occurrences of NULL values is stored in the NUMNULLS column of the system catalog view SYSCAT.COLUMNS.
关于null值出现次数的信息存储在系统编目视图syscat .COLUMNS中的NUMNULLS列中。
Because XQuery is case-sensitive, lowercase table and column names would fail to match upper-case names in the DB2 catalog.
由于XQuery是大小写敏感的，因此小写的表名和列名不能与DB 2编目中的大写名称相匹配。
Clew: This method just conceals driver icon, the user still can use other method to visit the content of driver, if key in the catalog method on driver directly in address column.
提示：这个方法只是隐藏驱动器图标，用户仍可使用其他方法访问驱动器的内容，如在地址栏中直接键入驱动器上的目录路径。
Clew: This method just conceals driver icon, the user still can use other method to visit the content of driver, if key in the catalog method on driver directly in address column.
提示：这个方法只是隐藏驱动器图标，用户仍可使用其他方法访问驱动器的内容，如在地址栏中直接键入驱动器上的目录路径。
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