SQL INSERT
Q1. What is the SQL INSERT command?
INSERT is used to add new rows to a table. It validates constraints, updates indexes, and records changes in transaction logs.
Q2. What happens internally when INSERT is executed?
The database allocates space, writes data to disk, updates indexes, and logs changes to ensure durability.
Q3. INSERT vs BULK INSERT – what is the difference?
Bulk insert operations reduce logging and improve performance for large data loads.
Q4. What is INSERT SELECT used for?
INSERT SELECT copies data from one table to another and is commonly used in ETL and migration scenarios.
Q5. What are common INSERT performance considerations?
Indexes and constraints slow inserts. Minimizing indexes and using batch inserts improves throughput.