Below are the Pre transaction limits
Description Synchronous Limit Asynchronous Limit
Total number of SOQL queries issued (This limit doesn’t apply to custom metadata types. In a single Apex transaction, custom metadata records can have unlimited SOQL queries.) 100 200
Total number of records retrieved by SOQL queries 50,000
Total number of records retrieved by Database.getQueryLocator 10,000
Total number of SOSL queries issued 20
Total number of records retrieved by a single SOSL query 2,000
Total number of DML statements issued 150
Total number of records processed as a result of DML statements, Approval.process, ordatabase.emptyRecycleBin 10,000
Total stack depth for any Apex invocation that recursively fires triggers due to insert, update, or delete statements 16
Total number of callouts (HTTP requests or Web services calls) in a transaction 100
Maximum timeout for all callouts (HTTP requests or Web services calls) in a transaction 120 seconds
Maximum number of methods with the future annotation allowed per Apex invocation 50
Maximum number of Apex jobs added to the queue with System.enqueueJob 50
Total number of sendEmail methods allowed 10
Total heap size 6 MB 12 MB
Maximum CPU time on the Salesforce servers 10,000 milliseconds 60,000 milliseconds
Maximum execution time for each Apex transaction 10 minutes
Maximum number of unique namespaces referenced 10
Maximum number of push notification method calls allowed per Apex transaction 10
Maximum number of push notifications that can be sent in each push notification method call 2,000