- How does bulk collect work in Oracle?
- What is the difference between bulk collect and forall?
- Does Oracle have stored procedures?
- Can we use bulk collect in cursor?
- What is bulk load in Oracle?
- What are cursors in SQL?
- Why do we use save exceptions clause during bulk binding?
- Which cursor is faster in Oracle?
- How do you handle exceptions in bulk collect?
- How do I pass one cursor to another cursor?
- What is cursor for loop in Oracle?
- What is bulk collect and bulk bind in Oracle?
- How do I choose my bulk collect limit?
- What are ref cursors in Oracle?
- What is Oracle performance tuning?
How does bulk collect work in Oracle?
A bulk collect is a method of fetching data where the PL/SQL engine tells the SQL engine to collect many rows at once and place them in a collection.
The SQL engine retrieves all the rows and loads them into the collection and switches back to the PL/SQL engine.
All the rows are retrieved with only 2 context switches..
What is the difference between bulk collect and forall?
Bulk collect: is a CLAUSE. is used to fetch the records from the cursor. Forall: is a STATEMENT. is used to do dml operation of fetched records. The body of the FORALL statement is a single DML statement — an INSERT, UPDATE, or DELETE.
Does Oracle have stored procedures?
Stored procedures and functions (subprograms) can be compiled and stored in an Oracle Database XE, ready to be executed. Once compiled, it is a schema object known as a stored procedure or stored function, which can be referenced or called any number of times by multiple applications connected to Oracle Database XE.
Can we use bulk collect in cursor?
This BULK COLLECT can be used in ‘SELECT’ statement to populate the records in bulk or in fetching the cursor in bulk. Since the BULK COLLECT fetches the record in BULK, the INTO clause should always contain a collection type variable.
What is bulk load in Oracle?
The bulk loader, bulkload , is a bulk management tool. It takes input data in LDIF or SQL*Loader format and loads the data directly into Oracle Internet Directory’s schema in the metadata repository. It has three main phases: check , generate and load .
What are cursors in SQL?
A cursor holds the rows (one or more) returned by a SQL statement. The set of rows the cursor holds is referred to as the active set. You can name a cursor so that it could be referred to in a program to fetch and process the rows returned by the SQL statement, one at a time.
Why do we use save exceptions clause during bulk binding?
Description Add the SAVE EXCEPTIONS clause to your FORALL statement when you want the PL/SQL runtime engine to execute all DML statements generated by the FORALL, even if one or more than fail with an error. If you use INDICES OF, you will need to take some care to find your way back to the offending statement.
Which cursor is faster in Oracle?
The output from the procedure clearly demonstrates that implicit cursors are faster than explicit cursors. The interesting thing is that the implicit cursor is not only faster, but it is actually doing more work, since it includes a NO_DATA_FOUND and a TOO_MANY_ROWS exception check.
How do you handle exceptions in bulk collect?
Key components of bulk DML with exception handling:A collection variable to hold the data.The FORALL construct which iterates through values in the collection variable.The SAVE EXCEPTIONS clause which tracks the exceptions being raised during bulk DML.More items…•
How do I pass one cursor to another cursor?
The trick to declaring a cursor within a cursor is that you need to continue to open and close the second cursor each time a new record is retrieved from the first cursor. That way, the second cursor will use the new variable values from the first cursor.
What is cursor for loop in Oracle?
The cursor FOR LOOP statement implicitly declares its loop index as a record variable of the row type that a specified cursor returns, and then opens a cursor. With each iteration, the cursor FOR LOOP statement fetches a row from the result set into the record.
What is bulk collect and bulk bind in Oracle?
Oracle uses two engines to process PL/SQL code. … If PL/SQL code loops through a collection performing the same DML operation for each item in the collection it is possible to reduce context switches by bulk binding the whole collection to the DML statement in one operation.
How do I choose my bulk collect limit?
How to Pick the Limit for BULK COLLECTStart with 100. … Test to see if that’s fast enough (likely will be for many cases).If not, try higher values until you reach the performance level you need – and you are not consuming too much PGA memory.Don’t hard-code the limit value: make it a parameter to your subprogram or a constant in a package specification.More items…•
What are ref cursors in Oracle?
Using REF CURSOR s is one of the most powerful, flexible, and scalable ways to return query results from an Oracle Database to a client application. A REF CURSOR is a PL/SQL data type whose value is the memory address of a query work area on the database. … A REF CURSOR refers to a memory address on the database.
What is Oracle performance tuning?
Performance tuning is the process of optimizing Oracle performance by streamlining the execution of SQL statements. In other words, performance tuning simplifies the process of accessing and altering information contained by the database with the intention of improving query response times and application operations.