32. What is Cross-Join? Cross join defines as Cartesian product where number of rows in the first table multiplied by number of rows in the second table. If suppose, WHERE clause is used in cross join then the query will work like an INNER JOIN....
SQL is a common language for Structured Query Language, which is based on general English, whereas MySQL is a database management system. Structured Query Language is the main part of the relational database, which can be utilized for gaining access to the database and also plays a major rol...
SQL Job Interview Questions and Answers 1 :: What is SQL (Structured Query Language)? SQL is an English like language consisting of commands to store, retrieve, maintain & regulate access to your database.Read More 2 :: What is the SQL*Plus? SQL*Plus is an application that recognizes &...
Astored procedure is a prepared SQL code. We can save the procedure in the database, so we can use it every time we need it without rewriting it. If we are using a query multiple times we can save it and store it as a procedure. For example, let’s we want to store the inner ...
Reference Types:Pointers to database objects, likeREF CURSORfor dynamic query processing. 4. What are the basic control structures in PL/SQL? PL/SQL includes several control structures that help manage the flow of a program: Loops:These includeLOOP,FOR LOOP, andWHILE LOOP, allowing repetitive ...
Solution of SQL Interview Question #2 The solution SQL query is: SELECT COUNT(*) FROM(SELECT user_id, COUNT(event_date_time) AS image_countFROM event_logGROUP BY user_id) AS image_per_userWHERE image_count < 2000 AND image_count > 1000; ...
4. What are the steps you will take to improve performance of a poor performing query? This is a very open ended question and there could be a lot of reasons behind the poor performance of a query. But some general issues that you could talk about would be: No indexes, table scans, ...
big query here ) SELECT * FROM YourTable1 WHERE ID IN (SELECT ID FROM YourBigCTE) UNION SELECT * FROM YourTable2 WHERE ID IN (SELECT ID FROM YourBigCTE) Scope is next immediate select command. Can be used multiple times within the same CTE command, even recursively, and will last for...
19.What is cost based optimizer? Answer: Cost Based Optimizer (CBO) uses the artificial intelligence to execute the Query. The Optimizer itself decides the execution plan based on the cost of query. The cost based method means the database must decide which query execution plan to choose. It...
请问您见过最惊艳的sql查询语句是什么？1、子查询 子查询允许将一个查询嵌套在另一个查询中，对于根据...