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Does Postgres use multiple cores?
The PostgreSQL server is process-based (not threaded). Each database session connects to a single PostgreSQL operating system (OS) process. Since version 9.6, portions of some queries can be run in parallel, in separate OS processes, allowing use of multiple CPU cores.
Is Postgres multi threaded?
The PostgreSQL server is process-based (not threaded). Each database session connects to a single PostgreSQL operating system (OS) process. Multiple sessions are automatically spread across all available CPUs by the OS. The OS also uses CPUs to handle disk I/O and run other non-database tasks.
How does a single PostgreSQL query use multiple cores?
The PostgreSQL server is process-based (not threaded). Each database session connects to a single PostgreSQL operating system (OS) process. Multiple sessions are automatically spread across all available CPUs by the OS. The OS also uses CPUs to handle disk I/O and run other non-database tasks.
What do you need to know about PostgreSQL cursors?
The query must be a SELECT, or something else that returns rows (such as EXPLAIN ). The query is treated in the same way as other SQL commands in PL/pgSQL: PL/pgSQL variable names are substituted, and the query plan is cached for possible reuse.
How to declare cursor variables in PL / pgSQL?
Declaring Cursor Variables All access to cursors in PL/pgSQL goes through cursor variables, which are always of the special data type refcursor. One way to create a cursor variable is just to declare it as a variable of type refcursor. Another way is to use the cursor declaration syntax, which in general is:
What do scroll and no scroll mean in PostgreSQL?
The SCROLL and NO SCROLL options have the same meanings as for a bound cursor. In this example, the table name is inserted into the query textually, so use of quote_ident () is recommended to guard against SQL injection. The comparison value for col1 is inserted via a USING parameter, so it needs no quoting.