What is a CTE (Common Table Expression), and how is it different from a subquery?
Answers were Sorted based on User's Feedback
Answer / nashiinformaticssolutions
• CTE: Temporary result set defined using WITH and reusable within the query. Improves readability for complex queries.
• Subquery: Nested query executed each time it is called. Example:
WITH SalesCTE AS (
SELECT employee_id, SUM(sales) AS total_sales
FROM sales
GROUP BY employee_id
)
SELECT * FROM SalesCTE WHERE total_sales > 5000;
| Is This Answer Correct ? | 0 Yes | 0 No |
Answer / glibwaresoftsolutions
• CTE: Temporary result set defined using WITH and reusable within the query. Improves readability for complex queries.
• Subquery: Nested query executed each time it is called. Example:
WITH SalesCTE AS (
SELECT employee_id, SUM(sales) AS total_sales
FROM sales
GROUP BY employee_id
)
SELECT * FROM SalesCTE WHERE total_sales > 5000;
| Is This Answer Correct ? | 0 Yes | 0 No |
• CTE: Temporary result set defined using WITH and reusable within the query. Improves readability for complex queries.
• Subquery: Nested query executed each time it is called. Example:
WITH SalesCTE AS (
SELECT employee_id, SUM(sales) AS total_sales
FROM sales
GROUP BY employee_id
)
SELECT * FROM SalesCTE WHERE total_sales > 5000;
| Is This Answer Correct ? | 0 Yes | 0 No |
How would you go about increasing the buffer cache hit ratio? 0. Explain the difference between a hot backup and a cold backup and the benefits associated with each 1. You have just had to restore from backup and do not have any control files. How would you go about bringing up this database? 2. How do you switch from an init.ora file to a spfile? 3. Explain the difference between a data block, an extent and a segment. 4. Give two examples of how you might determine the structure of the table DEPT. 5. Where would you look for errors from the database engine? 6. Compare and contrast TRUNCATE and DELETE for a table. 7. Give the reasoning behind using an index. 8. Give the two types of tables involved in producing a star schema and the type of data they hold. 9. What type of index should you use on a fact table? 10. Give two examples of referential integrity constraints. 11. A table is classified as a parent table and you want to drop and re-create it. How would you do this without affecting the children tables? 12. Explain the difference between ARCHIVELOG mode and NOARCHIVELOG mode and the benefits and disadvantages to each. 13. What command would you use to create a backup control file? 14. Give the stages of instance startup to a usable state where normal users may access it. 15. What column differentiates the V$ views to the GV$ views and how? 16. How would you go about generating an EXPLAIN plan?
Explain the advantages and disadvantages of stored procedure?
Does normalization improve performance?
What are pl sql data types?
what is a constraint? : Sql dba
what is difference between stored procedures and application procedures,stored function and application function?
How do I tune a sql query?
Can we create view in stored procedure?
what are sequences
What is Highwatermark?
What is a left join?
How many types of functions are there in sql?
Oracle (3259)
SQL Server (4518)
MS Access (429)
MySQL (1402)
Postgre (483)
Sybase (267)
DB Architecture (141)
DB Administration (291)
DB Development (113)
SQL PLSQL (3330)
MongoDB (502)
IBM Informix (50)
Neo4j (82)
InfluxDB (0)
Apache CouchDB (44)
Firebird (5)
Database Management (1411)
Databases AllOther (288)