Postgresql Ctid

• Ctid is for the location of a tuple.
• Ctid is a hidden and unique record for each table in PostgreSQL.
• Itempointer is the data type of the system column ctid. A tuple ID is a pair (block number, tuple index within the block).
• If you update or move a Row Version of ctid by using VACUUM FULL or AUTO-VACUUM to increase the overall performance.
• Ctid can be used to delete duplicate records, old version rows or dead rows in a table.

Syntax:

SELECT CTID,* FROM students;