Question 1

Do I need an External ID field in Salesforce?

Accepted Answer

No, which surprises most people. Identity can be any Salesforce field that is filterable and otherwise eligible, so an account number, domain or email column already on the object can serve as the key without creating a dedicated External ID field. Exact equality is standard, and string identities also support substring, domain and hostname matching as well as matching against a list of values.

Question 2

Does a frequent sync get expensive on the BigQuery side?

Accepted Answer

It can, and this is the part teams underestimate. BigQuery bills for bytes scanned, so a model reading a wide unpartitioned table every fifteen minutes costs real money regardless of how few records reach Salesforce. Set a tracking field, which incremental reads need alongside a unique identity, partition and ideally cluster the source, select only the columns you map, and avoid SQL that defeats partition pruning. Model syncs are differential after the first backfill, so the write side stays small even when the read side is not.

Question 3

How are lookups set?

Accepted Answer

Either by writing the reference identifier directly, or through generated find by fields that resolve the related record for you. That means a contact can be pointed at its account using the account's own identifier or an External ID style lookup, so Salesforce record identifiers do not have to be carried through your data warehouse. Where a reference does not resolve, you choose whether to fail the row, omit the relationship, or skip the record.

Question 4

What happens on a large first load?

Accepted Answer

The connector selects between the REST and Bulk APIs automatically based on volume, so a large backfill goes through Bulk rather than burning per record calls, and operations pause at 80 percent of your daily API allowance. Two settings matter at scale: only updating when values differ costs extra reads, and orgs prone to row locking usually want a smaller Bulk batch size with serial processing.

Connect BigQuery with Salesforce

Connect BigQuery and Salesforce with Polytomic

Match on any filterable field

API quota protected

Differential after backfill

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Step-by-step integration guide

Connect BigQuery in Polytomic

Connect Salesforce in Polytomic

Create a sync between BigQuery and Salesforce

Map fields and enable the sync

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