This chapter is designed to review the logical models and query languages used in spatial database systems. The chapter describes how the representation and querying of geographic objects can be supported by the
Similarly, add the isDrinker column to the Patient table, update its population, and finally drop the Indulges table. In practice, the most efficient way to migrate data may depend on theDBMS(s) being used. In contrast to the simple example just discussed, it is more typical to leave the...
Data Models in DBMS TheData Modelis defined as an abstract model that organizes data description, data semantics, and consistency constraints of data. The data model emphasizes on what data is needed and how it should be organized instead of what operations will be performed on data. Data Model...
on-demand物化视图不被sql apply自动刷新,必须执行dbms_mview.refresh来刷新他,在逻辑备库上刷新视图的例子: SQL> EXECUTE DBMS_MVIEW.REFRESH ( LIST => 'HR.DEPARTMENTS_MV', METHOD => 'F'); 在逻辑备库上创建的on-commit物化视图被自动维护,额外创建的on-demand物化视图不会被sql apply维护,必须使用dbms...
EXEC DBMS_LOGSTDBY.APPLY_SET('MAX_EVENTS_RECORDED', DBMS_LOGSTDBY.MAX_EVENTS); EXEC DBMS_LOGSTDBY.APPLY_SET('RECORD_UNSUPPORTED_OPERATIONS', 'TRUE'); This captures information about any transactions running on the primary that are not supported by logical standby. When the upgrade is complete an...
ODP.NET returns a logical transaction object,OracleLogicalTransaction, which is used to determine the outcome of the last open transaction in a database session following an outage. Without Transaction Guard, applications that attempt to retry operations following outages can cause logical corruption by...
2. To maintain data in a logical stand by database, SQL Apply operations must be able to identify the columns that uniquely identify each row that has been updated in the primary database. Tables that do not have primary keys or non-null unique indexes are identified by enabling supplemental...
to send the I/O requests and then to reap the results. Although Oracle uses the asynchronous interface to perform read operations in this example, the final result is very similar to what described in Example 2 (i.e. with synchronous I/O): the Oracle wait event is the same, "db file...
The VOL management module M201is the module for executing various operations for the logical VOL18of the storage device10in accordance with a request from the management client50. The VOL management module M201, upon receiving a request from the management client50, issues an indication to the st...
5.The system of claim 1, further comprising a backup service that adds three tracking columns to a base table of data in the partition of the distributed database, the three tracking columns utilized to track insert operations. 6.A computer-implemented data management method that employs a proc...