Table scan (TBSCAN) with partition pruning.
使用分区修剪的表扫描(TBSCAN)。
Indexes improve query performance by avoiding a full table scan.
索引能够避免全表扫描，从而能够提高查询性能。
Deterministic function calls can be extracted from the WHERE clause to avoid unnecessary table scan.
可以从WHERE子句中提取确定性函数调用，避免不必要的表扫描。
Thus, DB2 cannot use those indexes and resorts to a table scan to ensure a correct query result.
因此，DB 2不能使用那些索引，而是会采取表扫描来确保正确的查询结果。
Basically, it's weighing the choice of using the index to walk through the selected rows or doing a table scan.
基本上，它会权衡使用索引来遍历选择的行或者对表进行扫描这两种方式。
The optimizer, in the absence of current statistics, is choosing to do a table scan on both tables involved in the join.
在缺少当前统计的情况下，优化器选择对参与联接的两个表进行表扫描。
Since only one row is expected in the result set from this SELECT statement, the table scan here is considered an expensive operation.
因为该select语句的结果集中只期望一行，所以表扫描在这里被认为是代价较高的操作。
Since there is no COMMIT between the INSERT and SELECT statement, potentially the deadlock is caused by a table scan.
由于INSERT和select语句之间没有COMMIT，死锁可能是由表扫描引起的。
In this case, a table scan is very expensive, because the Informix engine has to access data randomly.
该例中，表扫描极其昂贵，因为Informix引擎必须随机地访问数据。
It looks like we are doing a sequential scan (of an entire table) to satisfy the SQL command, whatever it is.
好像我们正在进行顺序扫描(对整个表)来满足SQL命令的需求，不管它是什么。
When DB2 performs an index or table scan, DB2 will block on a row lock when it comes across an uncommitted row which another transaction has exclusively (X) locked.
DB2在执行索引或表扫描时，如果遇到一个被另一个事务独占 (X) 锁定的未提交行，那么 DB2将阻塞在行锁上。
We found a bigger difference for queries that touch a large number of rows, such as a table scan over all 20,000 XML documents with string comparison on every document.
我们发现涉及大量行的查询的性能差异比较大，比如对所有20,000个XML文档进行全表扫描并对每个文档比较字符串。
If there is no index on ucname, the DBMS still does a full table scan, but it need not do any further processing on the data to determine whether or not it satisfies the query.
如果没有为ucname创建索引，DBMS仍然执行全表扫描，但是不会对数据进行进一步处理来判断其是否满足查询。
DB2 can use both the relational and XML indexes to quickly pinpoint the data of interest, avoiding a costly scan of all rows in the table.
DB 2可以使用关系索引和xml索引来快速检索所关注的数据，避免了盲目地扫描表中的所有行。
When scanning an MDC table, block locking could be deferred for an index scan.
当扫描一个mdc表时，对于索引扫描，块锁可以推迟。
An index only scan is an index access that is not followed by a table access because the index itself contains all the requested data.
仅扫描索引是未包含表访问的索引访问，因为索引本身包含了所有被请求的数据。
An SQL optimizer may choose to scan an index rather than a table because indexes are usually smaller than tables, but this is a marginal improvement.
一个SQL优化器会选择扫描一个索引，而不是一个表，因为索引通常比表小，但是这只是一个微小的改进。
Once it has moved itself, it will proceed to scan the partition table for a bootable partition.
一旦它移动好自身，接下来就扫描分区表以寻找一个可启动分区。
To illustrate this, compare it to the predicate that is applied to the index scan numbered 5 in the plan, which is on the one and only column of the index on the child table.
为了展示这一点，将它与计划中第5号索引扫描上使用的谓词相比较，它针对子表中惟一的索引列。
Too many columns in a table can make the scan time for queries much longer than if there are just a few columns.
一个表中有太多列比仅有一些列时进行查询所需的扫描时间要长。
Typically, the optimizer chooses merge scan join when the cardinality of the outer input is not obviously small and there is no efficient access method for the inner table.
通常情况下，在外部输入的基数显然不小且对于内部表没有一种有效的访问方法时，优化器会选择合并扫描联接。
Table 2 summarizes how the performance of this table scan query has benefited from two of our design decisions: atom site separation and compression.
表2总结了此次表扫描的性能如何能从我们的两个设计决策中受益：原子站点分离和压缩。
The results can be displayed or printed in the form of peak data or scan data table.
结果可用图谱显示、打印、生成峰数据表、或扫描数据表等多种形式输出。
Number of probe scans. A probe scan is used to directly look up rows in an index or base table.
探测扫描的数目。探测扫描用于直接在索引或基表中查找行。
A probe scan is used to directly look up rows in an index or base table.
探测扫描用于直接在索引或基表中查找行。
The optimizer normally chooses a table scan if no appropriate index has been created or if an index scan would be more costly.
如果没有创建合适的索引，或者如果索引扫描的成本更高一些，优化器通常就选择表扫描。
Limited partition scan is a method that allows DB2 to limit the scan of data in a partitioned table space.
限定分区扫描允许DB 2将数据扫描限制在一个分区表空间中。
Most often, you want only a small subset of the data in the table, so a full table scan wastes a lot of disk I/O and therefore time.
通常来说，您可能只希望获得表中数据的一个子集，因此全表扫描会浪费大量的磁盘I/O，因此也就会浪费大量时间。
Since this query contains no value predicate to restrict either the books or the authors table, DB2 has to perform a table scan on either of the two tables to read all author IDs.
由于该查询没有包含用来限制books或authors表的值谓词，因此DB 2必须在两个表上执行表扫描，以便读取所有author ID。
The number of rows selected from each dimension table is less than the number of rows selected from the fact table after all scan filters are applied.
所有的扫描过滤器都应用后，每个维度表选出的行数少于事实表选出的行数。
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