What is SYSDATE?<\/strong><\/li>\n<\/ol>\n\n\n\nSYSDATE is a built-in Oracle function. It returns the current system date and time from the database server.<\/p>\n\n\n\n
Example:<\/strong><\/p>\n\n\n\nSELECT SYSDATE FROM DUAL; <\/p>\n\n\n\n
<\/span>Oracle Interview Questions for Experienced<\/span><\/h2>\n\n\n\nThis section covers advanced Oracle interview questions and answers often asked to professionals with hands-on experience in Oracle technologies.<\/p>\n\n\n\n
\n- How does Oracle manage memory in the SGA?<\/strong><\/li>\n<\/ol>\n\n\n\n
SGA (System Global Area) is a shared memory structure. It holds data like SQL execution plans, cached data blocks, and redo log info. Oracle divides SGA into components like the shared pool, buffer cache, large pool, and redo log buffer. These components help with efficient data access and query execution.<\/p>\n\n\n\n
\n- How do you perform backup using RMAN?<\/strong><\/li>\n<\/ol>\n\n\n\n
I use RMAN for both full and incremental backups. <\/p>\n\n\n\n
For example:<\/strong><\/p>\n\n\n\nBACKUP DATABASE PLUS ARCHIVELOG; <\/p>\n\n\n\n
RMAN automates backup validation, cataloging, and can be integrated with a recovery catalog for centralized control.<\/p>\n\n\n\n
\n- How does Oracle handle deadlocks?<\/strong><\/li>\n<\/ol>\n\n\n\n
Oracle detects deadlocks automatically. It rolls back one of the conflicting transactions to break the cycle. Deadlocks usually happen when two sessions wait for each other’s locks.<\/p>\n\n\n\n
\n- Explain flashback query and flashback table.<\/strong><\/li>\n<\/ol>\n\n\n\n
Flashback Query retrieves past data using AS OF timestamp. Flashback Table restores a table to a past state without recovery. Useful for fixing accidental changes.<\/p>\n\n\n\n
\n- What are Oracle hints and how are they used?<\/strong><\/li>\n<\/ol>\n\n\n\n
Hints guide the optimizer to use a specific plan. They are placed in comments:<\/p>\n\n\n\n
SELECT \/*+ INDEX(emp emp_idx) *\/ * FROM emp; <\/p>\n\n\n\n
Used to override the default plan when needed.<\/p>\n\n\n\n
\n- Describe the ANALYZE command and when you would use it.<\/strong><\/li>\n<\/ol>\n\n\n\n
The ANALYZE command gathers statistics or checks for corruption. It helps with optimizer decisions and object validation.<\/p>\n\n\n\n
Example:<\/strong><\/p>\n\n\n\nANALYZE TABLE emp COMPUTE STATISTICS; <\/p>\n\n\n\n
Note \u2013<\/strong> Although we have covered the commonly asked oracle experience interview questions, here are a few more based on your experience level.<\/p>\n\n\n\n