Latest Answer : Rollup summarises the group of data records based on key eg you want the income of a particular city from a set of records , you can use the rollup component.example dml is customer ,city name and amount (here the key ...
What is the difference between clustered and non-clustered indices? ...and why do you use a clustered index?
Latest Answer : explain plan can be reviewed to check the execution plan of the query. This would guide if the expected indexes are used or not. ...
Latest Answer : Explicitly chooses an index scan for the specified table. You can use the INDEX hint for domain, B*-tree, and bitmap indexes.CREATE INDEX ix_customers_genderON customers(gender);set autotrace traceonly explainSELECT *FROM customersWHERE gender = 'M';SELECT ...
Describe where you would use each of the following index types in relation to query type and/or data set: Hashed, Sorted, Bitmapped (Ranked), Clustered
In a process which reads 15,000 rows from one table and either updates or inserts them into another table and given the scenario where the process may abnormally terminate, describe how you track progress within the data to ensure the process could be restarted without repeating any processing.
In the scenario outlined in #18 and given that the output table(s) will be accessed by concurrent readers describe how your SQL code would be structured to minimize lock contention.
Describe which database structural and physical elements you would review when optimizing query performance.
