QueryLocator object when you are using a simple query (SELECT) to generate the scope of objects used in the batch job. If you use a querylocator object, the governor limit for the total number of records retrieved by SOQL queries is bypassed but we can retrieve up to 10,000 records.
What is difference between Database query and Database QueryLocator?
Database. query() is used to construct dynamic query instead of using SOQL query where as Database. getQueryLocator() is the return type of start method of a Batch class. Hope this helps!
Why do we use Database query locator?
The query locator can return upto 50 million records and should be used in instances where you want to bactha a high volume of data up (pagination or batch apex). The database. query method should be used in instances where you are wanting to do a dynamic runtime SOQL query for your code.
What is the difference between Database QueryLocator and iterable?
It depends on your need , if you want to run batch on records that can be filtered by SOQL then QueryLocator is preferable, but if records that you want to bee processed by batch can not be filtered by SOQL then you will have to use iteratable.
What is the return type of Database QueryLocator?
QueryLocator Methods
Returns the query used to instantiate the Database. QueryLocator object. This is useful when testing the start method. Returns a new instance of a query locator iterator.
Can we call future method from batch class?
Yes, we can’t call future method from batch class. Some restriction of the future method are: No more than 50 method {Methods with the future annotation} calls per Apex invocation.
What is Database stateful?
The only time you need Database. Stateful is when the execute method modifies a class variable in a way meant to be used across multiple execute methods or in the finish method. The majority of batches you will ever write will not need Database. Stateful.
What is the difference between SOQL and Database query ()?
Database. query can be used wherever a static SOQL query can be used, such as in regular assignment statements and for loops. Unlike inline SOQL, fields in bind variables are not supported. So the fundamental difference is the lack of support for variable binding.
What is Database Batchablecontext in Salesforce?
Represents the parameter type of a batch job method and contains the batch job ID. This interface is implemented internally by Apex.
What does a database contain?
A database is a data structure that stores organized information. Most databases contain multiple tables, which may each include several different fields. For example, a company database may include tables for products, employees, and financial records.
What is the maximum batch size in Salesforce?
Default batch size is 200 ,However maximum batch size is 2000. In BatchApex Governer LImit section you can find more details .
What is the use of Iterable Sobject?
Use iterable object when you have complex criteria to process the records.
What is the use of Iterable in batch apex?
Use the iterable to create a complex scope for the batch job. You can also use the iterable to create your own custom process for iterating through the list. To do the required processing for each chunk of data, use the execute method. This method is called for each batch of records that you pass to it.
Can we insert records using batch apex?
The batch Apex class can be tested by simply inserting some sample records in a test class and processing them using the batch class. Only one execution of the ‘execute’ method is possible in a test class.
How many callouts we can call in batch apex?
It’s per each call of execute() in the batch, so for each “batch”, you can call up to 10 HTTP callouts. If the callout can handle multiple records at a time, do so, and batch up to 10 callouts per batch, otherwise, set the batch scope to 1, so each apex batch handles one record at a time.
What is asynchronous apex in Salesforce?
Asynchronous Apex. In a nutshell, asynchronous Apex is used to run processes in a separate thread, at a later time. An asynchronous process is a process or function that executes a task “in the background” without the user having to wait for the task to finish.
How do I run a Queueable apex?
To add this class as a job on the queue, call this method: ID jobID = System. enqueueJob(new AsyncExecutionExample()); After you submit your queueable class for execution, the job is added to the queue and will be processed when system resources become available.
