Hi,

I have a trigger on Contact that will trigger an update on Account as below:
 

trigger calAccountLifeCycleStatus on Contact (after insert, after update) {
    List<id> acc_ids = new List<id>();
    List<Account> acc_toUpdate = new List<Account>();
    
    if(trigger.isInsert){
        for(Contact ctc : Trigger.new){
            acc_ids.add(ctc.AccountId);
        }
        
    }

    if(acc_ids.size() > 0){
        
        for(Account acc: [Select id, CalculateALC__c from Account where id in: acc_ids]){
            acc.CalculateALC__c = true;
            acc_toUpdate.add(acc);
        }
    }
    
    if(acc_toUpdate.size() > 0){
        update acc_toUpdate;
    }

}

then in my account i have this triggger -> class

my account trigger

trigger AccountLifeCycleUpdate on Account (before update) {
    AccountLifeCycleCal.calculate(trigger.New ,Trigger.NewMap, Trigger.OldMap);
}

my apex class

public without sharing class AccountLifeCycleCal{
     
    public static void calculate( List<Account> newAcc, Map<ID, Account> newAccMap, Map<ID, Account> oldAccMap){
		Map<Id, String> AccountStatusMap = new Map<Id, String>();
	
		for(Account acc_trigger: newAcc){
		
			if(acc_trigger.CalculateALC__c == true){
					acc_ids.add(acc_trigger.id);
			}
		}
				
		for(Account acc: [select id, name, Status__c,(select id, contact_type__c from Contacts) from Account where Id IN :acc_ids])
        {
			String AccountStatus = '';
			
			for(Contact c : acc.contacts){
				if(c.contact_type__c = 'A'){
					AccountStatus = 'customer';
					break;
				}			
			}			
			AccountStatusMap.put(acc.id, AccountStatus);
		}
		
		for(Account upd_acc: newAcc){
            if(acc_ids.size() > 0){
				upd_acc.Status__c = AccountStatusMap.get(upd_acc.id);
			}
		}
	}
}

when i do a batch import of 50k contacts, i kept getting this error 'unable to obtain exclusive access to this record' but when i import this error file again and it go through but still not all imported, still left a portion of contacts with that error, then i keep repeat import the error file.

is it due to the the trigger above?

Thanks.