Why SQL cursor is bad?
But, when you open a cursor, you are basically loading those rows into memory and locking them, creating potential blocks. Then, as you cycle through the cursor, you are making changes to other tables and still keeping all of the memory and locks of the cursor open.
What are the disadvantages of cursor in SQL?
What are the disadvantages of cursors?
- Uses more resources because Each time you fetch a row from the cursor, it results in a network roundtrip.
- There are restrictions on the SELECT statements that can be used.
- Because of the round trips, performance and speed is slow.
How do I fix my cursor in SQL?
Using SQL Server Management Studio
- In Object Explorer, right-click a server and select Properties.
- Click the Advanced node.
- Under Miscellaneous, change the Cursor Threshold option to the value you want.
Is it good to use cursor in SQL?
Cursors could be used in some applications for serialized operations as shown in example above, but generally they should be avoided because they bring a negative impact on performance, especially when operating on a large sets of data.
Why cursors are used in SQL?
In SQL procedures, a cursor make it possible to define a result set (a set of data rows) and perform complex logic on a row by row basis. By using the same mechanics, an SQL procedure can also define a result set and return it directly to the caller of the SQL procedure or to a client application.
What is the DISadvantage of cursor?
Disadvantages of using Cursor: So occupies more resources and temporary storage. Each time when a row is fetched from the cursor it may result in a network round trip. This uses much more network bandwidth than the execution of a single SQL statement like SELECT or DELETE etc that makes only one round trip.
What are the drawbacks of implicit cursors?
The implicit cursor has the following drawbacks:
- It is less efficient than an explicit cursor (in PL/SQL Release 2.2 and earlier)
- It is more vulnerable to data errors.
- It gives you less programmatic control.
Can cursor be part of a trigger body?
SQL Statements Allowed in Trigger Bodies statements or the SELECT statement in the definition of a cursor. DDL statements are not allowed in the body of a trigger. Also, no transaction control statements are allowed in a trigger.