Are temporary tables in postgresql visible over all client sessions?

Question

I want to create a temp table so as to be able to join it to a few tables because joining those tables with the content of the proposed temporary table takes a lot of time (fetching the content of the temporary table is time consuming.Repeating it over and over takes more and more time). I am dropping the temporary table when my needs are accomplished. I want to know if these temporary tables would be visible over other client session(my requirement is to make them visible only for current client session). I am using postgresql. It would be great if you could suggest better alternatives to the solution I am thinking of.

Answer 1

PostgreSQL then is the database for you. Temporary tables done better than the standard. From the docs,

Although the syntax of CREATE TEMPORARY TABLE resembles that of the SQL standard, the effect is not the same. In the standard, temporary tables are defined just once and automatically exist (starting with empty contents) in every session that needs them. PostgreSQL instead requires each session to issue its own CREATE TEMPORARY TABLE command for each temporary table to be used. This allows different sessions to use the same temporary table name for different purposes, whereas the standard's approach constrains all instances of a given temporary table name to have the same table structure.

Answer 2

Pleas read the documentation.

Temporary tables are only visible in the current session and are automatically dropped when the database session ends.

If you specify ON COMMIT, the temporary table will automatically be dropped at the end of the current transaction.

If you need good table statistics on a temporary table, you have to call ANALYZE explicitly, as these statistics are not collected automatically.