[SalesForce] Cloning opportunities – identifying which deals are “clones”

merry you get the exception, because you run out of opportunities that meet the criteria StageName = '09-Win' and Type 'Reseller / Partner Registration'. That is because your code does not necessarily clones the opportunity the user updates, but the first opportunity that is returned by your query

Opportunity opp = [select Id, closedate, account.name, account.id from Opportunity where StageName = '09-Win' and type = 'Reseller / Partner Registration'  LIMIT 1];

I strongly recommend you read https://force.siddheshkabe.co.in/2012/01/basic-of-writing-apex-trigger.html

Below the code, that archives what you are looking for

trigger partnerOpClone on Opportunity (after update) {

// accounts ids to query
Set<Id> oppAccountIds = new Set<Id>();
// opportunities we have to clone
Opportunity[] oppsToClone = new Opportunity[]{};
// clones to save
Opportunity[] oppsToSave = new Opportunity[]{};

String STAGE_WON = '09-Win';
String TYPE_PARTNER = 'Reseller / Partner Registration';

// bulkified handling
for (Opportunity record:trigger.new)
{

    // make sure the opportunity stage has been changed to new
    if (record.StageName == STAGE_WON && trigger.oldMap.get(record.Id).StageName !=  STAGE_WON
    && record.Type == TYPE_PARTNER)

    // keep for query
    oppAccountIds.add(toCheck.Id);

    // keep opps that meet the criteria for further processing
    oppsToClone.add(record);
}


// make sure we only continue , if there are any opps we have to cline
if (oppsToClone.size() > 0)
{

    // query accounts and store by there name to lookup it up quickly
    Map<Id,Account> accountMap = new Map<Id,Account>([
        select Id
             , Name
          from Account
         where Id IN: oppAccountIds]);

    // clone the opps
    for (Opportunity record:oppsToClone)
    {
        Opportunity theClone = record.clone(false,true);
        theClone.Amount = null;
        theClone.Name = accountMap.get(record.AccountId).Name + ' Partner';
        oppsToSave.add(theClone);
    }

    insert oppsToSave;
}

}

Here is the solution that I was discussing in the comments. It's very similar in concept to your's except it tries to reduce the number of DML and SOQL statements by grouping the Attachments into batches of 5MB (this will need adjusting, I just chose it to prove the concept).

The code could do with cleaning up a bit, and you'll want to change how the ParentIds are selected/assigned, but hopefully the concept is clear:

List<List<Id>> batches = new List<List<Id>>();
List<Integer> batchSizes = new List<Integer>();

for(Attachment attachment : [SELECT Id, BodyLength from Attachment WHERE ParentId = '5002000000ahX5f'])
{ 
    Boolean batched = false;

    for(Integer i = 0; i < batches.size(); i++)
    {
        Integer batchSize = batchSizes[i];

        if(batchSize + attachment.BodyLength < 10000000)
        {
            batches[i].add(attachment.Id);
            batchSizes[i] += attachment.BodyLength;
            batched = true;
            break;
        }
    }

    if(!batched)
    {
        batches.add(new List<Id>{attachment.Id});
        batchSizes.add(attachment.BodyLength);
    }

    System.debug('>>>first loop heap=' + Limits.getHeapSize());
}

for(List<Id> batchIds : batches)
{
    List<Attachment> attachmentsToInsert = new List<Attachment>();

    for(Attachment attachment : [SELECT Name, Body FROM Attachment WHERE Id IN :batchIds])
    {
        attachmentsToInsert.add(new Attachment(Name = attachment.Name, Body = attachment.Body, ParentId = '5002000000ahX5v'));
    }

    System.debug('>>> second loop heap=' + Limits.getHeapSize());
    insert attachmentsToInsert;
}

The output for an object with 5 Attachments (4.28MB, 1.23MB, 1.24MB, 3.59MB, 4.29MB) is as follows:

>>>first loop heap=1871
>>>first loop heap=1917
>>>first loop heap=1955
>>>first loop heap=1993
>>>first loop heap=2015

>>> second loop heap=4503453
>>> second loop heap=2589001
>>> second loop heap=4489577
>>> second loop heap=3759972

Number of SOQL queries: 5 out of 100
Number of DML statements: 4 out of 150

In this case it has only saved 1 DML, but with a lot of small Attachments or increasing the limit this will save a lot more.

For example, using a limit of 10MB gives you the following:

>>>first loop heap=1871
>>>first loop heap=1901
>>>first loop heap=1939
>>>first loop heap=1961
>>>first loop heap=1983

>>> second loop heap=9549616
>>> second loop heap=5788869

Number of SOQL queries: 3 out of 100
Number of DML statements: 2 out of 150