avg or norton

1. Name of person who obtains the highest salary in each department First step: Get the highest salary in each department Select Max (SAL) from the EMP group by DEPTNO; The second step: according to the results of the first step and the employee table to associate, get the name of the person Select A.empno,a.ename,a.sal,a.deptno from emp a join (select Deptno, max (SAL) max_sal from EMP Group by Deptno) b on A.D eptno= B.deptno and a.sal = b.max_sal; 2. Which person's salary is above the departm

', 1, ' 48 ',], [' Average QPS ', ' 167361 ', ' avg ', '%.2f ', 1, ' 48 '], [' Max QPs ', ' 167361 ', ' Max ', '%.2f ', 1, ' 48 '], [' Maximum QPS occurrence time ', ' 167361 ', ' Max ', '%.2f ', 1, ' 48 '], [' Maximum bandwidth (in) ', ' 81291 ', ' Max ', '%.2f ', ' 1048576 ', ' 48 '], [' Average bandwidth (in) ', ' 81291 ', ' avg ', '%.2f ', ' 1048576 ', ' 48 '], [' Maximum bandwidth (out) ', ' 81292 ',

show you how a sparksql job works, and by the way, how does sparksql and hive on MapReduce compare to each other at all? The solution to the SQL on Hadoop has been everywhere, whether it's the Ganso-level Hive,cloudera impala,mapr drill,presto,sparksql or even Apache TAJO,IBM Bigsql, Companies are trying to solve the performance problem with SQL interaction scenarios because the original hive on MapReduce is too slow. So where does hive on MapReduce compare to Sparksql or other interactive engi

. The young generation of G1 GC consists of Eden region and survivor region. When a JVM allocates Eden region fails, it triggers a young generation to recycle, meaning the Eden Zone is full. Then the GC begins to free up space, and the first young generation collector moves all the storage objects from Eden Region to Survivor Region, which is the "Copy to Survivor" process. As shown in Listing 1, the collection GC output log for the younger generation, in this log, see the last line, the young g

student values (05, ' Dragon ', ' Male ', 27, 56, 02);INSERT into student values (06, ' Big Joe ', ' female ', 17, 88, 01);INSERT into student values (07, ' Little Joe ', ' female ', 16, 96, 01);INSERT into student values (08, ' Little Joe ', ' female ', 16, 90, 01);INSERT into student values (09, ' Guan brother ', ' male ', 32, 80, 02);INSERT into student values (10, ' Liu Bei ', ' Male ', 98, NULL);ALTER TABLE student drop foreign key ' student_ibfk_1 ';***************************************

10 cases of high-concurrency MySQLSQL statement optimization in the production environment: This case is a database optimization teaching case for the linux O M training of Old Boys. If any reposted, you must retain this copyright statement in your actual work, O M or DBA personnel 10 cases of high-concurrency MySQLSQL statement optimization in the production environment: This case is a database optimization teaching case for the linux O M training of Old Boys. If any reposted, you must retai

current SQL On Hadoop job has similar working principles in the first half, similar to a Compiler. Xiaohong is data analysis. She wrote an SQL statement one day to calculate the weighted average score of a department. SELECT dept, avg (math_score * 1.2) + avg (eng_score * 0.8) FROM studentsGROUP BY dept; STUDENTS table is a student Score Table (please do not care that this table does not seem to conform to

the minimum value of the sal field in the emp table)47. select avg (sal) from emp; // (avg () calculates the average salary );48. select to_char (avg (sal), '192. 99') from emp; // (keep the average salary calculated only two decimal places)49. select round (avg (sal), 2) from emp; // (round the average salary to the

the current system time in 12-hour format)41. select to_char (sysdate, 'yyyy-MM-DD HH24: MI: ss') from dual; // (displays the current system time in 24-hour format)42. select ename, hiredate from emp where hiredate> to_date ('2017-2-20 12:24:45 ', 'yyyy-MM-DD HH24: MI: ss '); // (function to-date queries the employees who have joined the company after the given time)43. select sal from emp where sal> to_number ('$1,250.00', '$9,999.99'); // (function to_number () calculates the salary with spec

Nine, advanced query (group, sub-query)To inquire about an upgraded version:Need to use three sheetsEmployee table:DESC EMPEMPNO Employee NumberENAME Employee NameJob Employee PositionsMGR Boss Employee NumberHireDate Employee Entry DateSAL Employee Monthly SalaryCOMM Employee BonusesDEPTNO Employee Department Department numberView Current User:Show Users;SELECT * from EMP;Department Table:DESC DeptDEPTNO Department NumberDname Department NameLoC Department LocationsSELECT * FROM dept;Salary sca

where C # = '002') B Where a. score> B. score and a. s # = B. s #; 2. query the student ID and average score of students whose average score is greater than 60; Select S #, avg (score) From SC Group by S # having avg (score)> 60; 3. query the student ID, name, number of course selections, and total score of all students; Select Student. S #, Student. Sname, count (SC. C #), sum (score) From Student left Ou

Oracle Study Notes (7) -- Advanced query (1) Before learning advanced queries, let's take a look at how to view all the tables in the Oracle database. This is because we need to use several tables under the SCOTT user in the Oracle database (these tables are included in the Oracle database ). Grouping functions: grouping Functions Act on a group of data and return a value for a group of data. Common grouping functions: AVG, SUM, MIN, MAX, COUNT, WM_C