unionM,N: The row refers to the union of the rows with id values of M and N. derivedN: The row refers to the derived table result for the row with an id value of N. A derived table may result, for example, from a subquery in the FROM clause. subqueryN: The row refers to the...
7、Explain sociological triggers for language change by giving a typical example inthe history of English. 8、Explain briefly the four main individual learner factors that affect a learner's acquisition of a second language. 9、Give some lexical items to illustrate social dialects. Try to explain...
a. Viruses that integrate into the host genome, and trigger genetic instability. b. Persistent infections combined with long term inflammation What are the major points of genetic mutation? Define mutation as it relates to genes. Explain two specific types. Briefly describ...
Specifically, include the output column list for each node in the plan tree, schema-qualify table and function names, always label variables in expressions with their range table alias, and always print the name of each trigger for which statistics are displayed. The query identifier will also ...
一.OptimizingQueries with EXPLAIN The EXPLAINstatement can be used either as a way to obtain information about how MySQLexecutes a statement, or as a synonym for DESCRIBE: (1)When youprecede a SELECT statement with the keyword EXPLAIN, MySQL displays informationfrom the optimizer about the query...
The Earthquakes trigger other natural calamities such as landslides and tsunamis. Answer and Explanation: a Seismology can be defined as the study of earthquakes and seismic waves recorded at the time of an earthquake around the Earth. A seismologist......
Explain what an index trigger is and how it is different from an indemnity trigger. Explain the difference between a quota and a tariff. Which is more effective and why? Explain the relationship between aggregate output and income(Y).
Then patients in the different groups were given a suggestion to either forget or remember the memory which could later trigger the sense of déj a vu when they encountered the game or word.Other scientists have attempted to bring on déj a vu using virtual reality. One study found that ...
the variables names in expressions together with the table alias the name of each trigger for which statistics are displayed COSTS Includes the estimated start-up cost, and total cost, plus the estimated number of rows and estimated width of each row. ...
Init gangs cost: the duration that is taken to preprocess the execution plan that is generated by the QO and send the query request to the QE to trigger the start query phase. Unit: milliseconds. Start query cost: the duration of the initialization phase, which starts when the Init gangs...