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Can I use for loop in PostgreSQL?

Can I use for loop in PostgreSQL?

In PostgreSQL, we can also use a for loop without creating a function. Instead, we will create an anonymous block and in the block, we will define a for loop. In the above code, first, we created an anonymous block and in the block, we created an array variable with some values.

How do I create a loop in PostgreSQL?

The syntax of the for loop statement to iterate over a range of integers: [ <> ] for loop_cnt in [ reverse ] from.. to [ by step ] loop statements end loop [ label ]; If we analyse the above syntax: An integer variable loop_cnt is created at first, which is accessible inside the loop only.

How streaming replication works in PostgreSQL?

PostgreSQL saves the updated information of the primary server as a transaction log known as write-ahead log, or WAL, in preparation for crash recovery or rollback. Streaming replication works by transferring, or shipping, the WAL to the standby server in real time, and applying it on the standby server.

Does PostgreSQL support replication?

The process of copying data from a PostgreSQL database server to another server is called PostgreSQL Replication. The source database server is usually called the Master server, whereas the database server receiving the copied data is called the Replica server.

How do I loop a record in PostgreSQL?

Postgresql loop insert In Postgresql, the loop can be used to insert data into the table, suppose we want to insert some kind of data, again and again, then we can use the loop. Let’ create a table named dummy. CREATE TABLE dummy(id int); The above code will create a new table named dummy with one column named id.

What is the difference between streaming replication and logical replication?

TL;DR: Logical replication sends row-by-row changes, physical replication sends disk block changes. Logical replication is better for some tasks, physical replication for others. Note that in PostgreSQL 12 (current at time of update) logical replication is stable and reliable, but quite limited.

What is cascading replication PostgreSQL?

Cascading replication, introduced with PostgreSQL 9.2, enables a standby server to replicate from another standby server rather than directly from the primary, meaning replication changes “cascade” down through a hierarchy of servers.

How do I replicate a Postgres database?

For replication to be achieved in PostgreSQL there must be two servers that can communicate with each other. It will identify this server as master, which is the master server or the production server and the other one is the Slave server or Replica server or standby server that will have a copy of master server data.

What is PostgreSQL logical replication?

Logical replication is a method of replicating data objects and their changes, based upon their replication identity (usually a primary key). We use the term logical in contrast to physical replication, which uses exact block addresses and byte-by-byte replication.

Can we use for loop in SQL query?

In SQL Server, there is no FOR LOOP. However, you simulate the FOR LOOP using the WHILE LOOP.

How does PostgreSQL replication work?

Working of PostgreSQL Replication In PostgreSQL, there is usually one database server on which all the modification relate operations and requests are served. Those changes are applied to other database servers called the slave servers or standby database servers.

What is the use of for loop in PostgreSQL?

The for loop can be used effectively and conveniently as per our necessity to loop around or execute certain statements repetitively. Besides this, even the result set retrieved from a particular query can be iterated using for loop in PostgreSQL. This is a guide to PostgreSQL For Loop.

How do I stop looping in PostgreSQL?

We can use a plain loop with the EXIT WHEN statement to stop looping. Another type of looping statement is the loop, and the last one is the while loop. To understand the examples, you need to have basic knowledge of PostgreSQL functions and CRUD operation statements like SELECT, UPDATE, INSERT and DELETE.

How to print each row of an array in PostgreSQL?

Copy and paste the above code in your PostgreSQL /psql command prompt to create a function named displayRowValues that will return the value and print the notice for each row of the array passed the function while calling it.