Functions provide a single result by accepting input arguments and returning an output value. It has access to a single vdik B. As can be seen it is a single-AMP retrieval and the optimizer is using the unique primary index to access the row. In that sense, each AMP was a node. Also it performs any data conversion,aggregation,sorting,manipulate the disk sub system in the multi tasking and possibly parallel processing in the environment of the Teradata database. The HASHAMP function returns the identification number of the primary AMP for any Hash Bucket number. Aggregate Functions Aggregate functions are typically used in arithmetic expressions. What is the function of an AMP? However AMP worker tasks that invoke the function will be held for the period of time that a table operator executes externally. 13. Each AMP in Teradata has its own disk attached to it. 14. Which feature is unique to Teradata? A. In Teradata V1, the Access Module Processor (AMP) was the physical processing unit for all the Teradata database functions. It does output conversion and formatting C. It does the physical work associated with generating an answer set D. It develops the least expensive plan to return the requested response set ANS:: A,B,C. When no value is passed to the HASHAMP function, it returns a number that is one less than the number of AMPs in the current system configuration Aggregate functions operate on a group of rows and return a single numeric value in the result table for each group. Because Teradata Database hash functions are formally mature and mathematically sound, rows with unique primary indexes are always distributed in a uniformly random fashion across the AMPs, even when there is a natural clustering of key values. The SAMPLE clause is a Teradata extension to the ANSI SQL:2011 standard. HASHAMP function in Teradata. Each AMP then contained its own microprocessor, disk drive, file system, database software (Database Manager), Teradata Operating System (TOS), and YNET interface. The function returns the AMP number which will hold the table row in its vdisk. Some SQL functions, referred to as niladic functions… This method is much faster than randomized allocation, especially for large sample sizes. SQL Functions SQL functions return information about some aspect of the database, depending on the arguments specified at the time the function is invoked. If you drop a UDF and then recreate it to return a different type, Teradata Database ignores the existing statistics for that function during optimization. 1) First, we do a single-AMP RETRIEVE step from TDUSER.employee by way of the unique primary index "TDUSER.employee.EmployeeNo = 101" with no residual conditions. The concepts of protected mode and unprotected mode discussed earlier work the same for table functions and table operators. A. 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