45951. The data model produced from the reverse engineering process does not include intersection table data.
45952. If a database is built correctly the first time, it will not have to be redesigned.
45953. The SQL-92 command to change a table name is RENAME TABLE.
45954. Reverse engineering is the process of reading a database schema and producing a data model from that schema.
45955. The data model produced from the reverse engineering process is a true logical model.
45956. It is not easy to build a database correctly the first time.
45957. Typically, there should be at least two different copies of the database schema used in the redesign process.
45958. Information systems and organizations do not just influence each other; they create each other.
45959. Adding null columns to a table is straightforward.
45960. The NOT EXISTS keyword will be true if any row in the subquery meets the condition.
45961. Dependency graphs are diagrams that consist of nodes and arcs that show the dependencies of a database.
45962. The EXISTS keyword will be true if any row in the subquery meets the condition.
45963. Which of the following SQL statements are helpful in database redesign?
45964. What SQL command can be used to delete columns from a table?
45965. Database redesign is not terribly difficult if the:
45966. Which SQL-92 standard SQL command can be used to change a table name?
45967. The process of reading a database schema and producing a data model from that schema is known as:
45968. Taper needle jet is found in:
45969. Generally turbo charger is operated by:
45970. Qualitative governing is best suited for:
45971. Growler is associated with:
45972. High compression ratio result in:
45973. Some of the columns of a relation are at different sites is which of the following?
45974. Which of the following is true concerning a global transaction?
45975. A homogenous distributed database is which of the following?
45976. Replication should be used when which of the following exist?
45977. Storing a separate copy of the database at multiple locations is which of the following?
45978. A distributed database is which of the following?
45979. A semijoin is which of the following?
45980. Which of the following is a disadvantage of replication?
45981. A distributed database can use which of the following strategies?
45982. Which of the following is not one of the stages in the evolution of distributed DBMS?
45983. With failure transparency, all of the actions of a transaction are committed or none of them are committed.
45984. Each site (or node) in a distributed system is subject to the same types of failure as in a centralized system.
45985. Replication may use either synchronous or asynchronous distributed database technologies, although asynchronous technologies are more typical in a replicated environment.
45986. Synchronization for pull replication is less disruptive and occurs only when needed by each site, not when a central master site thinks it is best to update.
45987. With asynchronous technology, if any copy of a data item is updated anywhere on the network, the same update is immediately applied to all other copies or it is aborted.
45988. Databases that are stored on computers at multiple locations and are not interconnected by a network are known as distributed databases.
45989. An increasingly popular option for data distribution as well as for fault tolerance of any database is to store a separate copy of the database at each of two or more sites.
45990. Asynchronous technology can result in unsatisfactorily slow response time because the distributed DBMS is spending considerable time checking that an update is accurately and completely propagated across the network.
45991. A distributed unit of work allows various statements within a unit of work to refer to multiple remote DBMS locations.
45992. The purpose of timestamping is to avoid the use of locks.
45993. Data replication is favored where most process requests are read-only and where the data are relatively static.
45994. The cost to perform a snapshot refresh may depend on whether the snapshot is simple or complex.
45995. The semijoin approach saves network traffic.
45996. In a semijoin, only the joining attribute is sent from one site to another, and then only the required rows are returned.
45997. The problem of concurrency control is more complex in a distributed database.
45998. A distributed database has which of the following advantages over a centralized database?
45999. An autonomous homogenous environment is which of the following?
46000. A transaction manager is which of the following?