[Anjali]

Action poller acts as a timer in visualforce page. It is used to send an AJAX request to the server depending on the time interval whereas Rerender is used to refresh a particular section of the visualforce page.

[Anjali]

You can differentiate while considering where to use it:

Use SOQL when

1. You know in which objects or fields the data resides.
2. You want to retrieve data from a single object or from multiple objects that are related to one another.
3. You want to count the number of records that meet specified criteria.
4. You want to sort results as part of the query.
5. You want to retrieve data from number, date, or checkbox fields.

Use SOSL when

1. You don't know in which object or field the data resides and you want to find it in the most efficient way possible.
2. You want to retrieve multiple objects and fields efficiently, and the objects may or may not be related to one another.
3. You want to retrieve data for a particular division in an organization using the divisions feature, and you want to find it in the most efficient way possible.

[Anjali]

The only rule is that setters fire before action methods but yes there is no guaranteed order.

[Anjali]

Basically, actionPollar is a timer that sends an AJAX request to the server according to a time interval that you specify. Each request can result in a full or partial page update.

An <apex:actionPoller> must be within the region it acts upon. For example, to use an <apex:actionPoller> with an <apex:actionRegion>, the <apex:actionPoller> must be within the <apex:actionRegion>.

Hope this helps!

[Anjali]

To track the status of bulk data load jobs and their associated batches, you can achieve this from following steps:

1. From Setup, enter Bulk Data Load Jobs in the Quick Find box,
2. Then select Bulk Data Load Jobs.
3. Click the Job ID to view the job detail page.

[Anjali]

Dynamic apex in Salesforce provide freedom to create more flexible applications. It provides-

1. Access to sObject and field describe information.
2. Access Salesforce app information
3. It supports dynamic DML

[Anjali]

You can use outbound messages which can send a soap request to an endpoint using workflow, or you can use the streaming api where you can create push topics to send push notifications to subscribers.

You can get the help from here about outbound message- https://developer.salesforce.com/docs/atlas.en-us.api.meta/api/sforce_api_om_outboundmessaging_setting_up.htm

 

[Anjali]

Coarse-grained: A few objects hold a lot of related data that's why services have broader scope in functionality. Example: A single "Account" object holds the customer name, address, account balance, opening date, last change date, etc. Thus: Increased design complexity, smaller number of cells to various operations

Fine-grained: More objects each holding less data that's why services have more narrow scope in functionality. Example: An Account object holds balance, a Customer object holds name and address, a AccountOpenings object holds opening date, etc. Thus: Decreased design complexity , higher number of cells to various service operations. These are relationships defined between these objects.

Hope this helps !

[Anjali]

All these annotations are used at the Method level and enables us to expose an Apex method as a REST resource. And here are the differences -

HttpPut - Used for Create and Update
HttpPost - Used for Create

and there is another method also present- HttpPatch - Used for Update
So if you only wish to create a new record then you can use HttpPost. If you wish to first check if a record exists and only when it does not exists then create a new record, use HttpPut. And if you are sure that the record exists and in case it does not then you wish to throw error then use HttpPatch.

Hope this helps!