Drop Down MenusCSS Drop Down MenuPure CSS Dropdown Menu

Basic SQL Interview Questions

-
1. What is difference between decode and case?
2. How will you delete duplicate records?
3. how will select first 5 records from a table?
4. what are the psedu columns?
5. Difference between delete and truncate?
6. What are the type of constraints?
7. Under which constraints the index will be created?
8. What is the difference between union and union all?
9. How will you fetch nth max salary?
10. Difference between inner join and outer join?

Comments

Post a Comment

Popular posts from this blog

Pgbadger Feature In Postgresql

-
1. pgBadger reports everything about your SQL queries            Overall statistics            The most frequent waiting queries.            Queries that waited the most.            Queries generating the most temporary files.            Queries generating the largest temporary files.            The slowest queries.            Queries that took up the most time.            The most frequent queries.            The most frequent errors.            Histogram of query times.            Histogram of sessions times.            Users involved in top queries.            Applications involved in to...
Read more

rman interview and scenario based questions and answer and also rman(backup and recovery) discussions panel

-
set 1 1.What is RMAN? Recovery Manager (RMAN) is a utility that can manage your entire Oracle backup and recovery activities. 2.What is the difference between using recovery catalog and control file?  When new incarnation happens, the old backup information in control file will be lost. It will be preserved in recovery catalog. In recovery catalog we can store scripts.  Recovery catalog is central and can have information of many databases. 3.Can we use same target database as catalog?      No, The recovery catalog should not reside in the target database (database should be backed up), because the database can’t be    recovered in the mounted state. 4.How do you know that how much RMAN task has been completed?    By querying v$rman_status or v$session_longops 5.From where list & report commands will get input? Both the commands command quering v$ and recovery catalog views. V$BACKUP_FILES or many of the recovery catalog views such as RC_...
Read more

ERROR: operator does not exist: text ->> unknown LINE 1: ...stomer' as customer_name,sales_info ->>'PRODUCTS' ->>'produc... ^ HINT: No operator matches the given name and argument type(s). You might need to add explicit type casts.

-
postgres=# select * from sales; id | sales_info ----+---------------------------------------------------------------------------------- 1 | { "customer": "NIJAM", "PRODUCTS": {"product_name": "choclate","total_item": 6}} 2 | { "customer": "ABU", "PRODUCTS": {"product_name": "badam","total_item": 5}} 3 | { "customer": "UMAR", "PRODUCTS": {"product_name": "mobile","total_item": 1}} (3 rows) postgres=# SELECT sales_info ->>'customer' as customer_name,sales_info ->>'PRODUCTS' ->>'product_name' as name_of_product from sales where sales_info ->>'customer'='UMAR'; ERROR: operator does not exist: text ->> unknown LINE 1: ...stomer' as customer_name,sales_info -...
Read more

PostgreSQL Enterprise Manager - PEM Monitoring Tools

-
Image
Database administration and management is required for any database on which there are continuous business transactions.  If databases across enterprises are not monitored and maintained, then such databases are vulnerable to disasters, which eventually brings downtime to missions-critical application and, of course, it will incur losses in the business. Data is now one of the key assets for running a business, globally. Hence, it is one of the major responsibilities of enterprises to invest in resources for database monitoring and management. There are many database management and monitoring tools available for proactive database monitoring. In this article, we will look at  PEM – “PostgreSQL Enterprise Manager” .Enterprise Manager, or PEM, is a graphical database management/monitoring tool that can help database administrators, system administrators, database developers, database managers, system architects, and performance analysts manage databases efficiently and proacti...
Read more

VMWARE WORKSTATION 3,4,5,6,7,8,9,10,11,12,14,15...etc LICENSE KEYS COLLECTION

-
Image
Below tutorialdba.com collected and sorted out hundreds of universal License Keys for all major versions of VMware Workstation Pro (not for VMware Workstation Player) 4.x, 5.x, 6.x, 7.x, 8.x, 9.x, 10.x, 11.x, 12.x and v14.x on Windows and Linux platforms (support both 32-bit and 64-bit operating system) in this single post. Besides, we also provide some license keys for VMware other projects. Just enjoy and share them. // 4~14 Universal License Keys // Version License Keys VMware Workstation VMware Workstation 4.x.x ZHDH1-UR90N-W844G-4PTN6 G1NP0-T88AL-M016F-4P8N2 ZC14J-4U16A-0A04G-4MEZP J1WF8-58LDE-881DG-4M8Q3 VMware Workstation 5.x.x LUXRM-WP0DN-A256U-4M9Q3 DJXDR-NDT27-Y2NDU-4YTZK DA925-HP80U-Z8HDC-4WXXP 3KW2W-AYR2C-88M6F-4MDQ2 VMware Workstation 6.x.x A0E8R-YUDFV-6AK2F-4GAN2 CRX0D-VWL0V-7CJ6C-46C7A NA8RX-QPNDU-D2LA9-4WAZL 1H4WM-N21FZ-7GK2A-44U5U 6AJ6N-THY2P-42KEF-4WTFG FK8R9-LPCDT-88H4Y-4WRN3 KAR8R-T8MAL-K8J6A-4WDXQ YJEKW-JMFF4-YA1DC-4WTQ...
Read more