# LDV load performance: Bulk API and sharing deferral

*Platform Data Architect Study Guide · Data Migration · Last updated October 26, 2026 · https://www.certifyforce.com/study-guide/platform-data-architect/data-migration/ldv-load-performance-bulk-api-and-sharing-deferral*

Make tens of millions of records load fast: Bulk API 2.0 versus Bulk API batching and allocations, parallel versus serial mode and lock handling, sequencing roles, users, data and sharing rules, Public Read/Write and deferred sharing with the full recalculation, and trimming fields, automation and network overhead.

- Certification: Salesforce Platform Data Architect
- Exam section: Data Migration
- Study guide: https://www.certifyforce.com/study-guide/platform-data-architect

**Official exam objective:**

> Compare and contrast various techniques for improving performance when migrating LDVs into Salesforce.

## What the exam expects

- Choose Bulk API 2.0 or Bulk API for a large ingest, and explain batching, batch size and daily allocations.
- Pick parallel or serial mode, group children by parent, and handle lock failures and requeued batches.
- Sequence an initial load (roles, users, data, groups, then sharing rules one at a time) and use Public Read/Write or deferred sharing, ending with a full recalculation.
- Cut per-record work: only needed fields, triggers and flows bypassed for the load, clean data, session reuse, compression.
- Restart a failed Data Loader job without reloading what succeeded, and script repeatable loads with Data Loader batch mode or an ETL platform.

Key terms: **Bulk API 2.0** (asynchronous API that batches and retries automatically); **concurrency mode** (parallel or serial processing of Bulk API batches); **lock contention** (batches competing for the same parent or sharing rows); **defer sharing calculation** (a Support-enabled permission to suspend sharing rule and group membership calculations); **full recalculation** (the sharing rule recalculation required after resuming).

## Key facts

| Fact | Detail | Source |
|---|---|---|
| Batch allocation | 15,000 batches per rolling 24 hours, shared by both APIs | [Limits and Allocations](https://developer.salesforce.com/docs/atlas.en-us.salesforce_app_limits_cheatsheet.meta/salesforce_app_limits_cheatsheet/salesforce_app_limits_platform_bulkapi.htm) |
| Records uploaded per 24 hours | 150,000,000 for each API; separate from Data Loader's 150,000,000-record CSV maximum | [Limits and Allocations](https://developer.salesforce.com/docs/atlas.en-us.salesforce_app_limits_cheatsheet.meta/salesforce_app_limits_cheatsheet/salesforce_app_limits_platform_bulkapi.htm) |
| Bulk API 2.0 daily limit | Records uploaded per day, visible at /limits | [Bulk API 2.0 vs Bulk API](https://developer.salesforce.com/docs/platform/api-asynch/guide/bulk-common-diff-two-versions.html) |
| Bulk API batch size | Start at the 10,000 maximum | [General Guidelines for Data Loads](https://developer.salesforce.com/docs/platform/api-asynch/guide/asynch-api-planning-guidelines.html) |
| Queue throttling | Over 2,000 unprocessed requests from one org are delayed | [General Guidelines for Data Loads](https://developer.salesforce.com/docs/platform/api-asynch/guide/asynch-api-planning-guidelines.html) |
| Requeued batch | Up to 10 reprocessing attempts; failed records not retried | [General Guidelines for Data Loads](https://developer.salesforce.com/docs/platform/api-asynch/guide/asynch-api-planning-guidelines.html) |
| Data Loader command line | Windows only; encrypted password and process-conf.xml | [Command Line Introduction](https://developer.salesforce.com/docs/platform/data-loader-impl/guide/command-line-intro.html) |
| Deferral enablement | Not on by default; Customer Support enables it | [Defer Sharing Calculations](https://help.salesforce.com/s/articleView?id=sf.security_sharing_defer_sharing_calculations.htm&type=5) |
| After deferral | Resume and run a full sharing rule recalculation | [Defer Sharing Calculations](https://help.salesforce.com/s/articleView?id=sf.security_sharing_defer_sharing_calculations.htm&type=5) |

## Check yourself

- Why can sorting a child file by parent ID avoid serial mode?
- When should a Bulk API job run in serial mode?
- Why are Data Loader's batch size settings irrelevant when Use Bulk API 2.0 is selected?

## Sources

- [Loading Data from the API](https://developer.salesforce.com/docs/platform/salesforce-large-data-volumes-bp/guide/ldv-deployments-best-practices-api-loading-data.html)
- [General Guidelines for Data Loads](https://developer.salesforce.com/docs/platform/api-asynch/guide/asynch-api-planning-guidelines.html)
- [What's the Difference Between Bulk API 2.0 and Bulk API?](https://developer.salesforce.com/docs/platform/api-asynch/guide/bulk-common-diff-two-versions.html)
- [Defer Sharing Calculations](https://help.salesforce.com/s/articleView?id=sf.security_sharing_defer_sharing_calculations.htm&type=5)
- [Defer Sharing Calculation (Large Data Volumes)](https://developer.salesforce.com/docs/platform/salesforce-large-data-volumes-bp/guide/ldv-deployments-techniques-deferred-sharing-calculation.html)
- [Bulk API and Bulk API 2.0 Limits and Allocations](https://developer.salesforce.com/docs/atlas.en-us.salesforce_app_limits_cheatsheet.meta/salesforce_app_limits_cheatsheet/salesforce_app_limits_platform_bulkapi.htm)
- [Configure Data Loader](https://developer.salesforce.com/docs/platform/data-loader-impl/guide/configuring-the-data-loader.html)
- [Insert, Update, or Delete Data Using Data Loader](https://developer.salesforce.com/docs/platform/data-loader-impl/guide/inserting-updating-or-deleting-data.html)
- [When to Use Data Loader](https://developer.salesforce.com/docs/atlas.en-us.dataLoader.meta/dataLoader/when_to_use_the_data_loader.htm)
- [Extreme Force.com Data Loading, Part 1: Tune Your Data Model](https://developer.salesforce.com/blogs/engineering/2013/02/extreme-salesforce-data-loading-part-1-tune-your-data-model)
- [When to Use Data Loader (earlier version, doc 244.0)](https://developer.salesforce.com/docs/atlas.en-us.244.0.dataLoader.meta/dataLoader/when_to_use_the_data_loader.htm)
- [Data Loader Command Line Introduction](https://developer.salesforce.com/docs/platform/data-loader-impl/guide/command-line-intro.html)
- [Run in Batch Mode (Windows Only)](https://developer.salesforce.com/docs/atlas.en-us.dataLoader.meta/dataLoader/loader_batchmode_intro.htm)
- [Data Integration with Salesforce](https://architect.salesforce.com/docs/architect/decision-guides/guide/data-integration.html)

## About the full unit

The "Core concepts", "Exam traps" and "Worked scenario" sections of this unit, its 18 linked practice questions, and unlimited timed mock exams are included with the Platform Data Architect pack (USD $19): https://www.certifyforce.com/practice-exams